Medical News

Blood test could provide an early arthritis warning

Medical News - Mon, 03/23/2015 - 17:50

"Arthritis breakthrough as new test diagnoses condition up to a decade earlier," the Mail Online reports. The test measures proteins linked with arthritis.

The study aimed to see whether a blood test could be developed that could distinguish between different types of early stage arthritis.

The study included groups of people with established diagnoses, including those diagnosed with early-stage osteoarthritis (so-called "wear and tear arthritis") and rheumatoid arthritis (caused by the immune system).

It then measured and compared levels of different proteins in their blood.

Overall, it found that looking at a combination of the levels of three proteins in the blood could distinguish between the different types of early-stage arthritis. This suggested such a test could have promise.

This is still early-stage research. Further study needs to look at whether this test is reliable for identifying and distinguishing between the different forms of early-stage arthritis in practice.

Most importantly, it needs to be seen whether use of the test leads to earlier treatment, and whether this leads to an improvement in patient outcomes.

 

Where did the story come from?

The study was carried out by researchers from the University of Warwick and other institutions in the UK. No sources of funding were reported. Some of the authors have a patent based on this work.

The study was published in the peer-reviewed scientific journal Scientific Reports.

The Mail’s headline is premature, as we do not know how accurate this test will prove to be on further study or whether it would be introduced. The subheadings saying “There is currently no test, meaning some patients are only diagnosed when disease is so progressed that surgery is the only option” is also a little overdramatic and inaccurate. This reporting makes it sound like osteoarthritis currently has no diagnosis and management pathways in place, which is not the case. Osteoarthritis is usually diagnosed based on a person’s symptoms, examination findings and X-ray findings.

 

What kind of research was this?

This was laboratory research, which aimed to develop a blood test to allow the detection and differentiation between different types of early-stage arthritis.

Blood tests are already used to help diagnose or exclude certain types of arthritis, such as rheumatoid arthritis, which is linked to having particular proteins and inflammatory markers in the blood. However, osteoarthritis (OA) has no diagnostic blood test. OA is a degenerative joint condition, where the cartilage covering the ends of the bones becomes worn and thin, causing symptoms including pain, stiffness, swelling and crunching feelings in the joints.

It is currently diagnosed based on a combination of a person’s symptoms and findings from a clinical examination. X-rays can also detect characteristic changes to the joints, though these are often not present in early stages of the disease.

This study aimed to look at if there were any biochemical markers that could be detected in the blood that would help diagnose early-stage OA and distinguish it from other types of arthritis. Ideally, a diagnosis could be made before any of the more advanced joint changes set in, which could be detected by X-ray.

 

What did the research involve?

This study included groups of people (181 people in all) with different established diagnoses:

  • advanced OA
  • early OA
  • advanced rheumatoid arthritis (RA)
  • early RA
  • early non-RA inflammatory arthritis – people with early symptoms of an inflammatory arthritis, but not having the diagnostic features of RA
  • a healthy control group with no joint problems

The researchers took blood samples from these people and samples of the fluid in the joints (synovial fluid) from those with early-stage arthritis. They used advanced laboratory techniques to measure the amount of different proteins in these fluids. They particularly looked at the amount of:

  • anti–cyclic citrullinated peptide (CCP) antibodies – a marker for RA
  • citrullinated protein – a marker for inflammation
  • hydroxyproline – a building block that is part of the protein collagen – a structural protein found in cartilage and bone

They compared the levels of these markers in people from the different groups. They also assessed whether looking for a particular combination of levels of these markers would allow them to tell the different groups apart.

 

What were the basic results?

The researchers found that compared to healthy controls, blood levels of citrullinated proteins were increased in people with early OA and early RA. Generally, people with early arthritis tended to have higher levels of these proteins in the blood, while in advanced disease, levels were lower in the blood and higher in the joint fluid.

Levels of citrullinated proteins were not increased in people with other non-RA early-stage inflammatory arthritis.

Anti–CCP antibodies were found mainly in the blood of people with early RA.

Compared to health controls, increased levels of hydroxyproline were found in people with early OA and early non-RA, but not in people with early RA.

The researchers found that looking at the levels of all three proteins enabled them to discriminate between people with early OA, early RA, other non-RA early inflammatory arthritis, and healthy joints. This combination test correctly identified:

  • 73% of people with early OA
  • 57% of people with early RA
  • 25% of people with non-RA early inflammatory arthritis
  • 41% of people with healthy joints

The test also correctly identified:

  • 87% of people who did not have early OA
  • 91% of people who did not have early RA
  • 76% of people who did not have non-RA early inflammatory arthritis
  • 75% of people who did not have healthy joints

 

How did the researchers interpret the results?

The researchers say their study provides a novel biochemical blood test that could be used for the diagnosis and discrimination of early-stage arthritis. They say that this could help to support improved treatment and patient outcomes.

 

Conclusion

This laboratory study suggests that for people presenting with early joint symptoms, examining blood levels of a combination of proteins could help to distinguish people who have early-stage OA from those who have early-stage RA or other inflammatory arthritis. 

However, this study is in the early stages and so far has only looked at relatively small samples of people with confirmed diagnoses of these different conditions. A lot of further work needs to be done to examine the accuracy of such a blood test, and to see whether it could reliably identify and distinguish between people with these conditions presenting to doctors in real world practice. These studies should assess whether it offers an improvement on the current approach to diagnosis based on symptoms, clinical examination, imaging findings and other blood tests currently used – such as measurement of inflammatory markers, rheumatoid factor, or anti-CCP antibodies.

Even if such studies find that the test performs well, it is likely that it would not replace all other diagnostic tests, instead being used in combination with other methods, especially as it performed better at detecting some forms of arthritis than others.

Most importantly, it also needs to be seen whether using this blood test as a diagnostic method would actually lead to improved disease outcomes for people with arthritis, as suggested in the news reports.

While several of the risk factors associated with OA are unavoidable (e.g. increasing age, female gender, previous joint damage or abnormalities), maintaining a healthy weight and staying active could help prevent onset of the disease. RA is an autoimmune disease (where the body’s own immune cells attack the joints) with no established cause. However, smoking is associated with the development of the condition.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Arthritis breakthrough as new test diagnoses condition up to a decade earlier - with just a single drop of blood. Mail Online, March 22 2015

DISCOVERY of proteins could lead to diagnosis of arthritis up to ten years before symptoms. Daily Express, March 22 2015

Links To Science

Ahmed U, Anwar A, Savage RS, et al. Biomarkers of early stage osteoarthritis, rheumatoid arthritis and musculoskeletal health. Scientific Reports. Published online March 19 2015

Categories: Medical News

Climate change 'might bring rise in UK mosquito-borne diseases'

Medical News - Mon, 03/23/2015 - 14:00

"Mosquitoes heading for warmer UK," Sky News reports after a new review predicted climate change will make the UK a more hospitable environment for disease-carrying mosquitoes and ticks, leading to an outbreak of conditions normally seen in more tropical climates.

In the review, two authors searched the literature to identify evidence looking at the effect climate change in Europe could have on diseases carried by mosquitoes or other insects, such as ticks.

Mosquitoes thrive in warm and wet environments, so a rise in the average temperature could make the UK a more attractive destination. This could then lead to an increase in three diseases – malaria, dengue fever and chikungunya (a viral infection with symptoms similar to malaria) – in the UK by as early as 2030.

A review of this kind can only provide an estimate and cannot predict the future with 100% accuracy. However, it does show the potential public health dangers that could arise from climate change: a rise in the average temperature by just a few degrees centigrade could have a range of unpredictable effects on our environment.

Where did the story come from?

This study was written by two researchers from the Emergency Response Department, Public Health England (PHE), Porton Down. PHE is the NHS body responsible for protecting and improving public health in England.

One of the researchers received partial finding from the National Institute for Health Research's Health Protection Research Unit.

The study was published in the peer-reviewed medical journal Lancet Infectious Diseases.

What kind of research was this?

This was a literature review, where the researchers identified and discussed research on the effect climate change could have on the risk of vector-borne disease in the UK. Vector-borne disease is disease carried by a non-human organism (such as mosquitoes or ticks) that is then transmitted to humans.

The researchers searched literature databases to identify any published papers that had looked at vector-borne disease in Europe, and focused on reports that were potentially relevant to the UK.

They present a discussion of the issue and the evidence they identified. They also make various recommendations on monitoring and studying these vector-borne diseases, including how they are impacted by weather and climate.

The researchers clearly state that the views expressed in the article are theirs and "not necessarily those of the National Health Service, the NIHR, the Department of Health, or PHE".

What do the researchers say about mosquito-borne disease and climate change?

Insects regulate their body temperature by taking in heat from the environment. This means that increases in temperature could help them survive and incubate, thereby spreading any disease-causing organisms they carry, such as parasites, bacteria and viruses.

The researchers present evidence that has looked at the effects that 2C, 4C or 6C rises in average temperature could have on vectors carrying the following pathogens:

Of these pathogens, some (but not all) of the most extreme modelling scenarios suggest malaria could be present in the UK as early as 2030.

Climate assessment has suggested one type of mosquito that spreads dengue fever and chikungunya could theoretically live in warmer parts of the UK, and that by 2030 the climate could be even more well suited to this mosquito.

What do they say about malaria?

The researchers explain how malaria was regularly found in certain parts of the UK in the 1800s. The UK still has several species of mosquito capable of carrying the malaria parasite, albeit the less severe kind (Plasmodium vivax).

However, the researchers say rising summer temperatures could also support the development of the more severe malaria parasite (Plasmodium falciparum).

One group of researchers have modelled the effect climate change could have on P. falciparum. They estimate there will be between 1.5C and 5C increases in temperature between 2030 and 2100. Sustained transmission of the malaria parasite is still unlikely at these temperatures.

However, one of the most extreme model scenarios they looked at suggested there could be sustained transmission of the parasite (lasting at least one month of the year) in southern England by 2080 or, to a lesser extent, even as early as 2030.  

But, as the researchers say, antimalarial drugs and the UK health system should be able to minimise transmission.

What do they say about dengue fever and chikungunya?

The researchers say that since 1990, five different tropical species of mosquito have become adapted to the temperate climate of Europe. These species are potential vectors of the tropical diseases dengue, chikungunya and yellow fever.

In the past decade, there have been cases where one of these tropical mosquito species has been implicated in outbreaks of chikungunya and dengue in southern France, Italy and Croatia.

Climate change is predicted to permit the expansion of this species across Europe, including the south of the UK.

If these mosquitoes do become established in the UK, people with dengue or chikungunya who travel to the UK would then be a source of infection for the established mosquitoes.

Ongoing transmission would then depend on the local climate conditions controlling mosquito populations.

Two models suggested that by 2030-50, the climate in southern England could be more suitable for one species of mosquito that carries chikungunya and dengue.

Models also predicted transmission periods of one month to be possible in London by 2041, and one to three months of activity possible in southern England by 2071-2100.

What do the researchers conclude?

The researchers make the following recommendations about how the potential threat from vector-borne disease could be managed:

  • Continue to enhance UK surveillance of endemic and non-native vectors.
  • Improve understanding of the effect of climate change and develop strategies to deal with changing public health risks in a changing environment (such as wetland management).
  • Better understand the effect of extreme weather events (such as flooding and drought) on the risk of infectious disease, and work with environmental organisations to develop management plans to prepare for a disease outbreak resulting from an extreme event.
  • Develop improved models that incorporate the many drivers for change (such as climate and land use) for a range of vector-borne diseases.
  • Continue to work collaboratively across Europe sharing data on vector-borne diseases and risk assessment.
Conclusion

Overall, this review provides insights into how climate change might lead to the transmission of tropical diseases in what are currently temperate parts of the world, such as the UK. Predicting what may happen in the future can help countries make sure they are prepared for such an eventuality.

This review was informed by a search for relevant literature, but may not have captured or included all relevant studies. Most of the studies were modelling studies, which are reliant on various assumptions that may or may not turn out to be correct.

It's not possible to say with any certainty what will occur in the future. The authors also note that climate change is not the only factor affecting vector-borne diseases.

Many other factors are equally important, such as socioeconomic development and changes in how land is used. This adds to the difficulty in predicting exactly how much climate change might impact these diseases.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Mosquitoes Heading For Warmer UK - Experts. Sky News, March 23 2015

Mosquitoes 'could bring exotic diseases to UK'. BBC News, March 23 2015

Plague of mosquitos carrying deadly diseases is headed for Britain, scientists warn. The Daily Telegraph, March 23 2015

Warmer weather means mosquitoes carrying killer diseases including dengue fever 'could be in the UK by 2030'. Mail Online, March 22 2015

Links To Science

Medlock JM, Leach SA. Effect of climate change on vector-borne disease risk in the UK. The Lancet Infectious Diseases. March 23 2015. (Article not yet online)

Categories: Medical News

Research casts doubt on aspartame sensitivity

Medical News - Fri, 03/20/2015 - 13:31

"Sweetener linked to cancer is safe to use," reports the Mail Online.

Aspartame – a commonly used artificial sweetener – has been dogged by controversy, despite being deemed safe by food regulators in the UK, EU and US.

Some believe they are sensitive to the sweetener. Anecdotal reports suggest it can cause headaches and stomach upsets.

This study recruited 48 "aspartame-sensitive" individuals and tested whether giving them a cereal bar with or without aspartame would elicit the suspect symptoms. The study was a gold-standard double blind randomised controlled trial (RCT), meaning neither the participants nor those analysing the results knew which bar they had eaten. This made it a fairer and more rigorous test.

It showed that there was no difference in the symptoms reported after eating the aspartame-laced bar compared with the normal bar.

This provides evidence that aspartame fears may not be warranted in some people who believe they are sensitive to the ingredient. However, the study may have failed to recruit those most fearful of the sweetener, so we can’t rule out aspartame-related symptoms in this group.

This study also can’t tell us whether regular aspartame consumption may have any health effects in the longer term.

To find out more, read "The truth about aspartame".

 

Where did the story come from?

The study was carried out by researchers from the University of Hull, the Food Standards Agency (FSA), Imperial College London, University College Dublin, Institute of Food Research (UK) and Weill Cornell Medical College, Qatar.

It was funded by the Food Standards Agency.

The study was published open-access in the peer-reviewed medical journal PLOS One. This means it is free to view and download this aspartame research.

The Mail Online reported the story accurately. However, in stating that aspartame does not cause harm, it would be better to make clear that this study has only looked at short-term effects. This study also had nothing to do with verifying aspartame’s safety in regards to cancer, despite what the headlines may lead you to believe.

 

What kind of research was this?

This was a double-blind randomised control crossover study looking at whether aspartame causes any harmful symptoms in people who report sensitivity to it.

Aspartame is a commonly used artificial sweetener that is around 200 times sweeter than normal sugar. Since its introduction in the 1980s, there have been concerns over whether aspartame is safe. There are many anecdotal reports of it causing stomach upsets, headaches and other problems. However, this concern doesn’t match the evidence.

Aspartame has been approved as a safe food ingredient after assessment of the evidence by regulators in the UK, EU and US, all of which have independently assessed the best available evidence. Despite the regulatory assurance, some people report they are sensitive to aspartame and are convinced that it causes them problems. The current study wanted to investigate this "aspartame-sensitive" group, to see if the claims were true.

A double blind RCT like this is the gold standard of single study research. It is one of the best ways to investigate whether aspartame is affecting people who report being sensitive to it. Neither the study participants nor those analysing the results knew whether they were consuming aspartame. This helps to eliminate bias caused by pre-conceived ideas of whether it is harmful or not. The only thing more convincing in the evidence stakes than an RCT like this is a meta-analysis of many of them.

 

What did the research involve?

Researchers gave 48 UK adults who said they were sensitive to aspartame two cereal bars, at least one week apart. One of the bars was laced with 100mg aspartame. This is equivalent, the researchers say, to the amount found in a can of diet fizzy drink. The other was a normal cereal bar. After eating each bar, standard questionnaires were used to assess psychological condition, and 14 symptoms were rated repeatedly over the next four hours. Blood samples were also taken immediately after eating and four hours later – the same was done for urine samples, but at four-, 12-, and 24-hour intervals.

One of the cereal bars was laced with aspartame and one was not. However, neither the participant nor the person analysing the results knew which was which, making the test more objective and eliminating many sources of bias.

Individuals volunteering were classified as "aspartame-sensitive" if they reported suffering one or more symptoms on multiple occasions, and as a consequence were actively avoiding consumption of any aspartame in their diet.

A further 48 people who didn’t report aspartame sensitivity (controls) repeated the same experiment under the same conditions. This group was chosen to match the characteristics of the aspartame-sensitive group in terms of age and gender. The aspartame-sensitive group had 21 men and 31 women; the control group had 23 men and 26 women. The groups did not differ significantly for age (around 50), weight, BMI, waist or hip circumference.

The 14 aspartame sensitivity symptoms assessed were:

  • headache
  • mood swings 
  • hot or flushed 
  • nausea 
  • tiredness 
  • dizziness
  • nasal congestion 
  • visual problems 
  • tingling
  • bloating 
  • hunger 
  • thirst 
  • happiness
  • arousal

The researchers’ main analysis looked for differences in symptoms after eating the aspartame-laced bar in those reporting aspartame sensitivity, compared with those reporting no sensitivity.

 

What were the basic results?

The main finding was that none of the rated symptoms differed between aspartame and control bars, or between sensitive and control participants.

They also found aspartame and control bars affected levels of chemicals in the blood (GLP-1, GIP, tyrosine and phenylalanine levels) equally in both aspartame-sensitive and non-sensitive subjects.

However, there were intriguing differences between the aspartame-sensitive group and the aspartame non-sensitive group. For example, the aspartame-sensitive people rated more symptoms, particularly in the first test session, whether this was after eating the placebo bar or the aspartame bar.

The two groups also differed psychologically in how they handled feelings and perceived stress.

 

How did the researchers interpret the results?

The authors’ conclusion was firm: "Using a comprehensive battery of psychological tests, biochemistry and state of the art metabonomics, there was no evidence of any acute adverse responses to aspartame.

"This independent study gives reassurance to both regulatory bodies and the public that acute ingestion of aspartame does not have any detectable psychological or metabolic effects in humans."

 

Conclusion

This study shows that an aspartame-laced cereal bar caused no more adverse symptoms than a bar without aspartame in a group or people who said they were sensitive to aspartame. It also had no more adverse symptoms in a control group of people who did not think they were sensitive to aspartame.

The effects were monitored up to four hours after eating. This provides compelling evidence that aspartame doesn’t cause any short-term symptoms, even in people who think they are particularly susceptible to it, and report avoiding it as a result.

Limitations with the study include some missing symptom data, because not everyone was able to complete the ratings scale after eating the bars. However, you might expect someone with symptoms to fill it in, so not filling it in might signal a lack of symptoms. The sample size of around 90 participants was also relatively small. A larger sample size would have increased the conviction of the results.

The study authors reported problems recruiting participants, which brings us to the biggest limitation to consider. They anticipated 48 aspartame-sensitive people would be recruited within a year, but it took 2.5 years, despite high-level media coverage. A lot more non-aspartame-sensitive people (147 individuals) initially volunteered for the study before just one aspartame-sensitive individual participated. The researchers say this may reflect their genuine fear of aspartame consumption. Consequently, the 48 who participated may not be representative of the population of people who believe they are aspartame-sensitive, but it was impossible to recruit those most fearful, as they avoid taking part.

A further limitation is that the study looked only at short-term effects and cannot exclude the possibility of long-term, cumulative effects of aspartame on biological parameters and on a person’s psychological state. The dose given was also reported to be smaller than the daily intake of many individuals, but was greater than the intake at which the people reporting aspartame sensitivity believe they suffer symptoms.

Overall, this study provides evidence that aspartame fears may not be warranted in some people who believe they are sensitive to the ingredient. However, the study probably failed to recruit those most fearful of the sweetener. We don’t know if this group have symptoms caused by aspartame.

The conclusions of this study, and aspartame’s approval by food safety agencies in the US, UK and EU, provide quite robust reassurance that aspartame is safe for the vast majority of people. As with any ingredient, you can’t say for sure that some individuals won’t react badly to it. However, the findings from this study suggest this may be a perception of harm that is not necessarily borne out when tested rigorously.

The FSA website says that in December 2013, the European Food Safety Authority (EFSA) published an opinion on aspartame: "following a full risk assessment after undertaking a rigorous review of all available scientific research on aspartame and its breakdown products, including both animal and human studies. The EFSA opinion concluded that aspartame and its breakdown products are safe for human consumption at current levels of exposure".

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Controversial sweetener aspartame found in fizzy drinks and diet products 'does NOT cause harm', report declares. Mail Online, March 20 2015

Links To Science

Sathyapalan T, et al. Aspartame Sensitivity? A Double Blind Randomised Crossover Study. PLOS One. Published Match 18 2015

Categories: Medical News

Are half of all children's teeth really rotten?

Medical News - Fri, 03/20/2015 - 13:30

"Rotten teeth are secret reason why teens don't smile," revealed The Times today.

The Daily Mirror expressed shock over revelations that, "More than a quarter of British children are afraid to smile because they have such bad tooth decay".

It explained how "poverty and sugar" were to blame after evidence has emerged that the poorest in British society are "twice as likely" to suffer from oral disease.

Public Health England's director of dental public health, Dr Sandra White, said the survey highlighted "the need to urgently reduce the amount of sugary snacks and drinks in our children's diets".

She went on: "Fluoride is indisputable in preventing tooth decay, and by brushing teeth using fluoride toothpaste and also introducing water fluoridation where needed, we can significantly improve our children's dental health."

Quoted in The Independent, Professor Damien Walmsley, scientific adviser to the British Dental Association, said: "These inequalities [between rich and poor] are persistent, but avoidable, and both parents and government must accept their share of responsibility."

What is the basis for these current reports?

These figures were revealed in the latest of five large-scale Children's Dental Health Surveys covering England, Wales and Northern Ireland. These surveys have been carried out every 10 years since 1973 to monitor the oral health of the nation.

The new survey report outlines changes in oral health since the last survey in 2003, and provides information on the distribution and severity of oral diseases and conditions in 2013.

The latest survey gives estimates of the dental health of 5-, 8-, 12- and 15-year-olds using data collected on a random sample of children by NHS dentists and nurses at dental examinations in schools.

Information on the children's experiences, perceptions and behaviours relevant to their oral health was collected from parents and 12- and 15-year-old children using self-completion questionnaires.

What did it find?

There was some good news. There were reductions in the extent and severity of tooth decay present in the permanent teeth of 12- and 15-year-olds overall in England, Wales and Northern Ireland in the last 10 years (2003 to 2013).

Decay was found in around a third of 12-year-olds (down from 43% in 2003) and half of 15-year-olds (46%, reduced from 56% in 2003). Around a third of 5-year-olds and almost half of 8-year-olds were found to have decay in their milk teeth.

However, large proportions of children continue to be affected by poor oral health. This directly affects their lives in significant and serious ways, such as not wanting to smile or problems eating food.

Children from poor families (judged by eligibility for free school meals) were more likely to have oral disease than other children of the same age:

  • a fifth (21%) of the 5-year-olds from poor backgrounds had severe or extensive tooth decay, compared with 11% of 5-year-olds whose families were richer
  • a quarter (26%) of the 15-year-olds from poor backgrounds had severe or extensive tooth decay, compared with 12% of 15-year-olds who were not eligible for free school meals

Oral health affected the health and wellbeing of older children and their families, too:

  • a fifth of 12- and 15-year-olds (22% and 19% respectively) reported experiencing difficulty eating in the past three months
  • more than a third (35%) of 12-year-olds and more than a quarter (28%) of 15-year-olds reported being embarrassed to smile or laugh because of the condition of their teeth
  • 58% of 12-year-olds and 45% of 15-year-olds reported that their daily life had been affected by problems with their teeth and mouth in the past three months

The majority of older children were positive about their oral health. About half of 12-year-olds (51%) and 60% of 15-year-olds were satisfied with the appearance of their teeth.

However, problems with oral health were common, and these impacted on children and their families:

  • a fifth of 12- and 15-year-olds (22% and 19% respectively) reported having difficulty eating in the past three months, and 35% of 12-year-olds and 28% of 15-year-olds reported being embarrassed to smile or laugh because of the condition of their teeth
  • nearly a quarter (23%) of the parents of 15-year-olds said they had taken time off work in the last six months because of their child's oral health, and 7% of parents of 5-year-olds said this

Severe or extensive decay was seen in around one in seven of the 5- and 15-year-old children (13% and 15% respectively).

How does this news affect me?

This study is a stark reminder to children, young people and parents of the importance of good oral health from the time a baby gets their first milk teeth. Poor oral health can have a significant impact on a person's life.

Today's report does not suggest or endorse ways to combat the issues raised, but we have covered stories in the past that offer potential solutions for discussion.

These include adding fluoride to water to prevent tooth decay, more consistent advice on how to brush teeth, and teaching and supervising tooth brushing in schools.

Read more about preventing tooth decay.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Half of children have tooth decay - with poverty and sugar blamed for epidemic. Daily Mirror, March 19 2015

Nearly half British children and teenagers have tooth decay. The Independent, March 19 2015

Almost HALF of eight year olds and a third of five year olds have fillings or missing teeth because of decay. Daily Mail, March 19 2015

'Half of eight-year-olds have tooth decay'. BBC News, March 19 2015

Half of children have tooth decay, national survey finds. The Times, March 19 2015

Categories: Medical News

Following UK dietary advice may cut heart disease risk

Medical News - Thu, 03/19/2015 - 16:00

"Sensible diet cuts heart attack risk in months," The Times reports after a randomised controlled trial found evidence that following current UK diet guidelines can reduce cardiovascular disease risk factors such as blood pressure and cholesterol levels.

We know that being a healthy weight and not smoking can help lower the risk of cardiovascular diseases such as heart attacks and strokes, but the evidence that healthy people benefit from low-salt, low-fat diets is weaker.

One of this study's strengths is its randomised design, which is actually uncommon with diet studies. This helps reduce the possibility that other factors influenced the results. Limitations include the fact this was a small study (165 participants) carried out over a relatively short time period.

Blood pressure and cholesterol measures are good indicators of the chances of someone having a heart attack or stroke, but not as reliable as waiting to see whether people in the study actually did so. It would be difficult (and possibly unethical) to do a dietary study that lasted long enough to show these outcomes.

The study suggests that if healthy middle-aged people follow current UK dietary recommendations, there may well be benefits, but we can't be sure of the size of the protective effect.

Where did the story come from?

The study was carried out by researchers from King's College London and was funded by the UK Food Standards Agency, the Department of Health, and the National Institute for Health Research.

It was published in the peer-reviewed medical journal The American Journal of Clinical Nutrition. It has been published on an open access basis, so it is free to read online.

A number of the authors have worked, or are currently working, for food manufacturers and medical companies, which could represent a conflict of interest.

The UK media reported the study with enthusiasm, with the Daily Mirror describing fruit and veg as a "lifesaver".

The Guardian did a good job of reporting the different outcomes, but did not report that some of the key measures did not show any improvement.

But none of the papers questioned how the overall "one-third" reduction figure mentioned by the researchers was calculated.

What kind of research was this?

This was a randomised controlled trial that compared the effects of following two types of diet.

One was based on a nutritionally balanced standard UK diet. The other included current UK nutritional guidelines, which recommend reduced salt, saturated fat and sugar intake, and an increased consumption of oily fish, fruit, wholegrain and vegetables.

Randomised controlled trials are a good way of comparing the true effects of a treatment or diet. However, the 12-week study could only look at the effects the diets had on markers such as blood pressure and cholesterol levels, but not long-term outcomes such as heart disease and stroke.

What did the research involve?

The researchers recruited 165 healthy non-smoking UK volunteers aged 40 to 70. They all had health checks at the start of the study, and were then split randomly into two groups. One group was asked to follow a standard UK diet while the others followed a diet based on healthy eating guidelines.

After 12 weeks, the health checks were repeated and the researchers looked for differences in blood pressure, cholesterol and other measures of heart attack risk that could have been caused by the different diets.

People selected to be in the study had an average risk of having a heart attack or stroke in the next 10 years.

The researchers ensured health check measurements, such as blood pressure, were reliable by using 24-hour blood pressure monitors rather than just taking one-off measurements.

Volunteers also had urine tests throughout the study so the researchers could estimate how well they were sticking to their allotted diets by checking their nutrient levels.

The dietary guidelines group were given dietary advice to help them reach the salt, fat, sugar and other targets in the healthy guidelines, and were advised to choose low-fat dairy products and lean cuts of meat.

The standard group were advised to eat a balanced "British" diet with no salt or sugar restrictions, based on bread, pasta and rice, potatoes with meat, limited oily fish, and wholegrain cereals. They were asked to eat full-fat dairy products.

Both groups were asked to limit their intake of sweets, cakes, biscuits and crisps, and to drink alcohol within safe limits.

Before the study began, the researchers agreed to look for three main outcomes, which they said would indicate an important change in people's heart attack risk. These were:

  • a reduction in daytime systolic blood pressure of 4mmHg (the higher blood pressure figure, which shows the pressure of the blood when it is pumped out of the heart)
  • a 5% change in the ratio of total cholesterol to HDL (or "good") cholesterol
  • a 1% reduction in blood vessel stiffness (flow mediated dilation)

While they reported on many other outcomes in the study, these are the key ones to look at. The researchers reported the effects of treatment as the comparison between the diet groups at the end of the study, adjusted to take account of differences between the participants before the study began.

However, it is not clear from the study how the researchers calculated the overall reduction in risk of having a heart attack or stroke from all the changes combined.

What were the basic results?

The main result was that people who followed healthy dietary recommendations reduced their daytime blood pressure measurement by an average of 4.2mmHg compared with the standard diet group, which was more than the researchers had hoped.

However, the average change in cholesterol ratio was less than expected – 4%, below the hoped-for 5%. There was no significant difference in change in blood vessel stiffness.

The people following the dietary recommendations lost weight compared with the standard diet group (average difference 1.9kg), even though that was not the intention of the study.

How did the researchers interpret the results?

The researchers said the change in blood pressure was "remarkable" and would "suggest" a reduction in the risk of having a fatal stroke of 54%, as well as a 39% drop in the risk of getting heart disease, for people following the healthy diet, depending on age.

They attribute about half of the drop in blood pressure to the effect of eating less salt. They say the change in cholesterol levels for the dietary guidelines group, although "modest compared with drugs such as statins", would still reduce the risk of heart disease by about 6%.

They concluded that, "selecting a diet consistent with current dietary guidelines compared with a traditional United Kingdom dietary pattern" would be likely to cut the chances of having a heart attack or stroke for people in the general population by 30% based on previous research.

Conclusion

This study showed that following dietary recommendations closely for 12 weeks can reduce blood pressure by a significant amount, which is likely to cut the chances of having a heart attack or stroke for an average healthy middle-aged person. The diet also affects cholesterol levels, but the overall effect of this may be modest.

The study appears to have been carefully conducted to avoid biasing the results. The researchers gave butter or margarine spread and cooking oil to people in both groups, for example, and asked everyone to fill out food diaries, as well as taking urine samples for nutrient analysis.

This may have improved the chances of people sticking to the diet they were allocated to. The methods used to analyse blood pressure and other health checks were rigorous and likely to produce reliable results.

However, it is disappointing that the study report is not clear about how the researchers reached the headline figure of a one-third drop in the risk of a heart attack or stroke.

The report includes much detail about changes to individual risk factors, such as different ways to measure cholesterol, but does not explain how the researchers calculated the overall risk reduction.

That said, this is a well-conducted study that offers good-quality evidence of the effects of following the current UK dietary recommendations.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Sensible diet cuts heart attack risk in months. The Times, March 19 2015

Diet with more fruit, fish and nuts cuts heart attack risk, say researchers. The Guardian, March 18 2015

Healthy diet means heart attack risk reduction says study. ITV News, March 19 2015

Links To Science

Reidlinger DP, Darzi J, Hall WL, et al. How effective are current dietary guidelines for cardiovascular disease prevention in healthy middle-aged and older men and women? A randomized controlled trial. The American Journal of Clinical Nutrition. Published online March 18 2015

Categories: Medical News

New blood test could help prevent antibiotic misuse

Medical News - Thu, 03/19/2015 - 14:40

"A new blood test can help doctors tease out whether an infection is caused by a bacteria or a virus within two hours," BBC News reports. The test, which looks at protein pathways in the blood, could help to appropriately target the use of both antibiotics and antivirals.

In many cases, it is unclear whether a person’s symptoms are being caused by a viral or bacterial infection, and current testing can take up to several days to find out.

In cases of severe illness, antibiotics are usually prescribed while waiting for the results, and this can contribute to antibiotic resistance.

Israeli-based researchers who developed the test used 1,002 children and adults who had been admitted to hospital. The test was good at distinguishing between viral and bacterial infections, and separating people with and without an infectious disease.

However, it needs to be used by a greater number people, to test its effectiveness, and has not yet been used to influence treatment. Further research, including randomised controlled trials, will be required before it could be used in a clinical setting.

Where did the story come from?

The study was carried out by researchers from several institutes and medical centres in Israel. It was funded by MeMed, a company based in Israel that designs and manufactures diagnostic tests. Most of the researchers were employed by MeMed and some reported owning stock options with the company.

The study was published in the peer-reviewed medical journal PLOS One. It is published on an open-access basis, so is free to read online.

The research was accurately reported by BBC News.

What kind of research was this?

This was a laboratory study, which used blood samples from a cohort of patients admitted to hospital. It aimed to develop a blood test that could distinguish between viral and bacterial infections.

Overuse or incorrect use of antibiotics leads to the inadvertent selection of bacteria that have resistance to them. Over time, the resistant bacteria can become more common, making the drugs less useful.

This is causing global concern, as infections that have been easy to treat with antibiotics may now emerge as serious, life-threatening conditions. This can happen by people being given "broad spectrum antibiotics". This happens when an infection is suspected, but before any microbiological results can show the exact type of infection. This means that some people will be given the wrong antibiotic, too many antibiotics or an antibiotic for illness caused by viruses, which will be ineffective.

Current tests that can be speedily obtained when an infection is suspected include non-specific markers of infection and the number of different white blood cells. These cells are specialised to fight different types of infections, with neutrophils mainly fighting bacteria and lymphocytes mainly fighting viruses. However, the interpretation of these tests is not straightforward, as both can be increased in each type of infection.

The researchers wanted to develop a test that could show whether the infection is from a bacteria or virus, so that fewer

What did the research involve?

The researchers took blood samples from 30 people and measured a number of proteins that are produced by the immune system in response to bacterial or viral infections. They used this information to create a blood test that measured these proteins. They then tested how accurate it was in 1,002 children and adults admitted to hospital with or without a suspected infection.

They used a systematic literature review to identify 600 proteins that can increase during bacterial and viral infections. Using samples from 20 to 30 people, half of whom had a viral infection and half a bacterial infection, they whittled down the number of proteins that are distinctly raised in each type of infection to 86. They then looked at the level of these proteins in 100 people, half with each infection, and found that 17 of the proteins were the most useful. Using statistical programmes, they chose three proteins for their final test. These were:

  • CRP (C-Reactive Protein) – a protein that increases in response to tissue injury, infection and inflammation; this is routinely used in clinical practice
  • IP-10 (Interferon gamma-induced protein-10)
  • TRAIL (Tumour necrosis factor [TNF] related apoptosis-inducing ligand)

The researchers then used the test on blood samples from children and adults from two medical centres who were suspected of having an infection due to a fever of over 37.5C developing within 12 days of the onset of symptoms. A control group consisted of people who were not suspected of having an infection – such as people with suspected trauma, stroke or heart attack – or healthy people.

People were excluded who had:

  • evidence of acute infection in the previous two weeks
  • immune deficiency from birth
  • immunosuppressant treatment
  • cancer
  • HIV
  • hepatitis B or C

After all usual test results were obtained, a panel of three clinicians individually reviewed the clinical notes and test results, and recorded whether each person had a bacterial infection, viral infection, no infection, or that it was unclear. The three doctors made their assessment independently and were not told what the other doctors had decided, and did not know the result of the test in development. They compared findings from this expert panel with the results of their blood test.

What were the basic results?

A total of 765 participants were diagnosed with either a viral infection, bacterial infection or no infection. Additionally, there were 98 people who did not have a clear diagnosis.

The test was good at distinguishing between viral and bacterial infections, and separating people with and without an infectious disease. The test remained robust regardless of where the infection was, such as in the lungs or the gut, or variables such as age.

Results were not clearly presented for the 98 people without a firm clinical diagnosis.

How did the researchers interpret the results?

The researchers concluded that "the accurate differential diagnosis provided by this novel combination of viral- and bacterial-induced proteins has the potential to improve management of patients with acute infections and reduce antibiotic misuse".

Conclusion

This new test shows promising results in distinguishing between viral and bacterial infections. This is important because of increasing antibacterial resistance and could help doctors to tailor treatment quicker when someone is admitted with a suspected infection.

At present, distinguishing between different types of infections is complex and relies on symptoms, signs, a variety of clinical tests and clinical judgement. One of these tests is the CRP, which is used as an indicator of the severity of infection or inflammation, and is often used to monitor this over time. It is surprising that it has been used as one of the determinants in this new test, as it is considered to be a non-specific marker of inflammation or infection and increases in both viral and bacterial infections.

While the results of the study are positive, it’s important to realise that the test is not ready to be used on the general population. It will need to be tested on larger groups of people to confirm its accuracy. In addition, studies will need to show that it delivers benefits to patients in the way it is hoped – for example, finding out whether using this test leads to more accurate prescribing of antibiotics, less antibiotics being prescribed, or speeds up the process of diagnosing infection. Further research along these lines, including randomised controlled trials, will be required before it could be used in the clinical setting.

Although the test appeared to be good at distinguishing between viral and bacterial infections, it is unclear what results were obtained for people who did not end up with a clear diagnosis using the best existing methods. We do not know if the new test gave a result for these people or was inconclusive. This group doesn’t appear to benefit from the old or new testing methods, so will need to be explored in the next phases of research.

You can help slow down antibiotic resistance by always completing a course of prescribed antibiotics, even if you feel well before the end of the suggested course of treatment. Remember: antibiotics are not effective against colds, most sore throats and flu.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Rapid blood test to 'cut antibiotic use'. BBC News, March 19 2015

Links To Science

Oved K, Cohen A, Boico O, et al. A Novel Host-Proteome Signature for Distinguishing between Acute Bacterial and Viral Infections. PLOS One. Published online March 18 2015

Categories: Medical News

Damage to 'heart health' may start in childhood

Medical News - Wed, 03/18/2015 - 15:30

"Children are suffering damage to their hearts as early as 12 due to poor diets," the Mail Online reports.

A US study has found high levels of known risk factors for heart disease in children. The study has not shown the direct effect these risks have in this age group, but it has raised concerns that they may affect the heart from childhood.

The study looked at four related risk factors known to contribute towards heart disease in adults:

They are:

Researchers surveyed 8,961 children and found that less than 1% of children aged two to 11 ate a healthy diet. Nearly a third of the children were overweight or obese.

80% of the children only met one of the five elements considered to be part of an "ideal" diet:

  • four or five portions of fruit and vegetables a day
  • fish twice a week
  • low salt
  • low added sugar in drinks
  • regular wholegrains

While heart damage in later life was not directly assessed in this study, it does highlight the need for further health promotion strategies. Heart disease has now overtaken cancer as the leading cause of death in developed countries.

While it is not clear to what extent these US findings relate to the UK population, the UK is in the midst of its own obesity epidemic. The latest figures suggest that the UK is now the "fat man of (Western) Europe", with one in four British adults now obese.

 

Where did the story come from?

The study was carried out by researchers from Northwest University in Chicago, the University of North Carolina at Chapel Hill and the University of Colorado School of Medicine. No external funding was reported.

The study was published in the peer-reviewed medical journal Circulation: Cardiovascular Quality and Outcomes.

On the whole, the Mail Online reported the story well, but there were some inaccuracies. The headline that stated damage to the heart starts before the age of 12 was not confirmed by the study. While it is likely that the increased cholesterol, BMI, poor diet and high blood pressure in this age group may be bad for the heart, the study did not directly check for any damage to the heart. They did point out some of the limitations of the study – specifically, using adult dietary recommendations for children and not adjusting this for the amount of exercise they take.

 

What kind of research was this?

This was a cross-sectional study, which measured how common risk factors for cardiovascular disease are in childhood.

Cardiovascular diseases (which affect the heart and blood vessels) are the leading cause of death globally. There are several known risk factors for cardiovascular disease, which are smoking, high blood pressure, obesity, high cholesterol, diabetes, low levels of physical activity and poor diet. Previous research has shown that managing these risk factors from adolescence is associated with reduced risk of cardiovascular disease.

This research aimed to provide a national reference point for these risk factors in children under the age of 12 in the US. This will help researchers to assess how successful future strategies are in tackling childhood obesity, by looking for changes in these measures over time.

 

What did the research involve?

The researchers used information from a large US study called The National Health and Nutrition Examination Survey (NHANES). These surveys collect data from adults and children across the US every two years, using a home interview and a health examination.

This study looked at four cardiovascular risk factors for 8,961 children who had participated between 2003 and 2010. These were:

  • diet
  • cholesterol level
  • blood pressure
  • BMI

Dietary intake was assessed by two interviews with the child’s carer (parent or guardian) and recorded dietary intake over the previous 24 hours. An "ideal diet" was considered to meet the following five criteria:

  • 4.5 or more cups of fruit and vegetables per day
  • two or more servings of fish per week
  • three or more servings of wholegrains per day
  • less than 1.5 grams of salt per day
  • less than 450 calories of added sugar in drinks per week

This broadly matches current UK recommendations for a healthy diet for children.

Children were then classified into three groups, according to how many of these criteria they fulfilled:

  • "ideal diet" – meeting four or five criteria
  • "intermediate diet" – meeting two or three criteria
  • "poor diet" – meeting none or one of the criteria

Similarly, they also classed the children’s other measurements (such as BMI, blood pressure and cholesterol) as "ideal", "intermediate" or "poor", based on standard criteria.

 

What were the basic results?

The main results were:

  • 99.9% of children did not have an ideal healthy diet, with most (over 80%) having a poor diet
  • 38% did not have an ideal cholesterol level
  • about 8% did not have ideal blood pressure
  • about 30% of children did not have an ideal BMI (were overweight or obese)

When combining the results for children aged eight to 11:

  • no children had ideal levels for all four cardiovascular health measures (diet, cholesterol, BMI and blood pressure)
  • 39% of boys and 38% of girls had three ideal measures
  • all children had ideal levels for at least one measure

 

How did the researchers interpret the results?

The researchers concluded that "with the exception of diet rated as intermediate or poor for nearly all children, the majority of children observed from ages two to 11 years had ideal CVH [cardiovascular health] for BMI, total cholesterol and blood pressure, thereby starting life with generally favourable CVH metrics". However, they are concerned about the rise in obesity and the effect this has on cardiovascular health. They say that "promoting the recommended dietary habits, physical activity as part of daily life, and arresting the growing trend of obesity are keys to achieving more favourable CVH metrics and long-term freedom from cardiovascular disease".

 

Conclusion

This large US survey has found high rates of poor diet, as well as overweight and obesity in children, some of whom also had high blood pressure and cholesterol. The data was collected over a number of years, and should be nationally representative, but may not be representative of each year individually.

Other limitations acknowledged by the researchers include the following:

  • Potential inaccuracies in parental reporting of the children’s diet over the previous 24 hours. This could be due to poor recall or being unaware of food the child consumed outside of the home.
  • An average ideal dietary intake for adults was used, rather than individual estimates of the required dietary intake per child according to their level of energy expenditure, height, weight, growth rate and age.
  • Some children participated in each of the two-yearly surveys, so their results will be included at each age group. This may have affected the results.
  • The survey did not collect data on smoking or secondhand smoke exposure, physical activity level or type 2 diabetes.

While the study did not directly assess heart damage, as might be assumed from the news coverage, it does suggest that children in the US frequently have risk factors for developing cardiovascular disease. It is not clear whether the results are representative of what might be seen in the UK, but it is known that overweight and obesity are becoming more common.

Overall, the study highlights the need for measures to encourage healthy diet and lifestyle from an early age. Installing healthy habits at a young age may make it more likely that said habits will persist into adulthood.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Damage to the heart can start before the age of 12 if young people have a poor diet. Mail Online, March 18 2015

Links To Science

Ning H, Labarthe DR, Shay CM, et al. Status of Cardiovascular Health in US Children Up to 11 Years of Age - The National Health and Nutrition Examination Surveys 2003–2010. Circulation: Cardiovascular Quality and Outcomes. Published online March 17 2015

Categories: Medical News

Breastfed babies 'grow up to be brainier and richer'

Medical News - Wed, 03/18/2015 - 15:00

"Breastfed babies grow up smarter and richer, study shows," The Daily Telegraph reports. A study from Brazil that tracked participants for 30 years found a significant association between breastfeeding and higher IQ and income in later life.

This study followed almost 3,500 infants from birth to adulthood in Brazil. It found babies who were breastfed longer had higher IQs at the age of 30, as well as higher incomes. The authors say this is the first study to directly assess the impact of breastfeeding on income.

Another novel feature of the study was that the majority of the mothers were from low-income backgrounds. Studies in developed countries, such as the UK, may be skewed by the fact there is a trend for breastfeeding mothers to come from medium- to higher-income backgrounds.

The study used a good design and had a relatively high follow-up of participants (almost 60%) given how long it was. Although factors other than breastfeeding may have been influencing the results, the researchers did try to reduce their impact by making adjustments. The results for income may also not be as representative of more developed countries.

While it's difficult to conclusively state that breastfeeding itself definitely directly caused all of the differences seen, overall this research supports the view that breastfeeding can potentially benefit children long-term.

Current UK advice is that exclusive breastfeeding for around the first six months of life provides a range of health benefits for babies

Where did the story come from?

The study was carried out by researchers from the Federal University of Pelotas and the Catholic University of Pelotas in Brazil.

It was funded by the Wellcome Trust, the International Development Research Center (Canada), CNPq, FAPERGS, and the Brazilian Ministry of Health.

The study was published in the peer-reviewed medical journal Lancet Global Health on an open-access basis, so it is free to read online or download as a PDF.

The majority of the UK media provided a very balanced report of this study, noting the results and their implications, as well as the study's limitations.

What kind of research was this?

This was a prospective cohort study looking at whether breastfeeding was associated with higher IQ and income in adulthood. The short-term benefits of breastfeeding on a baby's immunity are well known.

The researchers also report that a meta-analysis of observational studies and two randomised controlled trials (RCT), which looked at the promotion of breastfeeding or compared breast milk versus formula in preterm babies, found longer-term benefits on IQ in childhood and adolescence.

There have been fewer studies looking at the effect on IQ in adults, all from developed high-income countries, but none looking at income.

Although two out of these three studies found a link with higher IQ, there is concern that this may at least in part be related to the fact that mothers of higher socioeconomic status in these countries tend to breastfeed for longer.

In the UK, women from a middle or upper class background are more likely to breastfeed than women from a working class background, so the researchers wanted to look at the link in a lower-income country (Brazil) where this pattern does not exist.

This is likely to be the best study design for assessing this question, as randomised controlled trials allocating babies to be breastfed or not are unlikely to be unethical.

As with all observational studies, the main limitation is that factors other than the one of interest (breastfeeding in this case) could be having an impact on the results, such as socioeconomic status.

Researchers can reduce the impact of these factors (confounders) by using statistical methods to take them into account in their analyses.

In this study, they also chose to analyse a population where a major confounder was thought to have less impact. There may still be some residual effect of these or other unmeasured factors, however.

What did the research involve?

The researchers recruited 5,914 babies born in 1982 in Pelotas, Brazil and their mothers, and recorded whether the babies were breastfed or not. They then followed them up and assessed their IQ, educational achievements and income as 30 year olds in 2013.

The researchers invited all mothers of babies born in five maternity hospitals in Pelotas in 1982 and who lived in the city to take part in their study, and almost all agreed.

When the babies were infants (19 months or 3.5 years old) the researchers recorded how long they were breastfed and whether they were mainly breastfed (that is, without foods other than breast milk, teas or water).

Researchers who did not know about the participants' breastfeeding history assessed their IQ using a standard test when they reached about 30 years of age. They also recorded the highest level of education participants had reached and their income in the previous month.

The researchers then compared outcomes in those who were breastfed longer against those who were breastfed for a shorter period of time or not at all.

They took into account a large range of potential confounders assessed around the time of the baby's birth (such as maternal smoking in pregnancy, family income, and baby's gestational age at birth) and during infancy (household assets). 

What were the basic results?

The researchers were able to follow-up and analyse data for 59% (3,493 individuals) of the participants they recruited.

About a fifth of babies (21%) were breastfed for less than a month, about half (49%) were breastfed for between one and six months, and the rest (about 30%) for longer than this. Most babies were mainly breastfed for up to four months, with only 12% mainly breastfed for four months or longer.

Longer duration of any breastfeeding or mainly being breastfed was associated with higher levels of education, adult IQ and income.

For example, compared with those who were breastfed for less than one month, those who had received any breastfeeding for a year or longer had:

  • IQ scores 3.76 points higher on average (95% confidence interval [CI] 2.20 to 5.33)
  • 0.91 more years of education on average (95% CI 0.42 to 1.40)
  • a higher than average monthly income (95% CI 93.8 to 588.3) – this was equivalent to around an extra 30% of the average income in Brazil

The researchers carried out a statistical analysis that suggested the difference seen in income with longer breastfeeding was largely a result of differences in IQ.

How did the researchers interpret the results?

The researchers concluded that, "Breastfeeding is associated with improved performance in intelligence tests 30 years later, and might have an important effect in real life by increasing educational attainment and income in adulthood."

Conclusion

This large long-term study found an association between being breastfed for longer and subsequent educational attainment, IQ and income at the age of 30 in participants from Brazil.

The authors say this is the first study to directly assess the impact of breastfeeding on income. The study used a good design and had a relatively high follow-up of participants (almost 60%) given its duration.

However, there are some points to note:

  • As with all observational studies, factors other than breastfeeding may have been influencing the results. The researchers did try to reduce their impact by making statistical adjustments, but some residual impact may remain.
  • There was less awareness of the benefits of breastfeeding in Brazil when the study started, so less association with socioeconomic status and education was expected. However, researchers did find that women who had the least, as well as the most, education and those with a higher family income tended to breastfeed more, although the differences tended to be small (less than 10% difference in frequency of breastfeeding at six months).
  • The results for IQ support those seen in higher-income countries, but there have not been any direct assessments of the effect of breastfeeding on income in these countries so far, and these may differ from lower-income countries.

While it's difficult to conclusively state that breastfeeding itself definitely directly caused all of the differences seen in this study, this research supports the belief that breastfeeding potentially has long-term benefits.

Breastfeeding is known to bring health benefits, and current UK advice is that this can be achieved through exclusive breastfeeding for around the first six months of life.

However, as experts noted on the BBC News website, breastfeeding is only one of many factors that can contribute to a child's outcomes, and not all mothers are able to breastfeed.

For more advice on breastfeeding, visit the NHS Choices Pregnancy and baby guide.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Breast-fed babies grow up smarter and richer, study shows. The Daily Telegraph, March 18 2015

The longer babies breastfeed, the more they achieve in life – major study. The Guardian, March 18 2015

Breastfeeding 'linked to higher IQ'. BBC News, March 18 2015

Longer breastfeeding 'boosts IQ'. Daily Mail, March 18 2015

Breastfeeding 'linked to success and higher IQ'. The Independent, March 18 2015

Breastfed babies earn more as adults. The Times, March 18 2015

Links To Science

Victoria CG, Horta BL, de Mola CL, et al. Association between breastfeeding and intelligence, educational attainment, and income at 30 years of age: a prospective birth cohort study from Brazil. The Lancet Global Health. Published online March 18 2015

Categories: Medical News

Obese people 'underestimate how much sugar they eat'

Medical News - Tue, 03/17/2015 - 14:30

"Obese people are 'in denial' about the amount of sugar they eat," the Mail Online reports. Researchers looking into the link between sugar consumption and obesity found a "huge gap" between overweight people's self-reported sugar consumption and the reality, according to the news story.

Researchers assessed the self-reported sugar consumption (based on food diaries) and sugar levels in urine samples in about 1,700 people in Norfolk. After three years, they had their body mass index (BMI) measured.

The researchers found those whose urine test suggested they actually consumed the most sugar were more likely to be overweight after three years compared with those who consumed the least. However, the opposite was true for self-reported sugar intake.

The specific role of sugar (rather than calorie intake as a whole) in obesity is unclear, and previous studies have had inconsistent results.

One limitation of this study is that the spot-check urinary sugar test may not be representative of sugar intake over the whole study period. Also, the results may be affected by factors not taken into account by the analyses.

Although the news story focuses on the suggestion that overweight people are "in denial" about what they eat, this study itself did not attempt to explain the discrepancy between diet diaries and urine sugar measurements.

Overall, the main conclusion of this study is that more objective measures, rather than subjective diet-based records, may help future studies to better disentangle the effects of sugar on outcomes such as being overweight. 

Where did the story come from?

The study was carried out by researchers from the universities of Reading and Cambridge in the UK and Arizona State University in the US.

It was funded by the World Cancer Research Fund, Cancer Research UK, and the Medical Research Council.

The study was published in the peer-reviewed medical journal Public Health Nutrition. It is available on an open-access basis, so is available to download for free.

The Mail focuses on the suggestion that overweight people are "in denial" about what they eat. But this study did not assess why the discrepancies between diet diaries and urine sugar measurements exist. It also does not question some potential problems with the urine tests, which could undermine the results.

What kind of research was this?

This was a prospective cohort study, part of the European Prospective Investigation into Cancer and Nutrition (EPIC), a long-running investigation. It aimed to see whether people who ate more sugar were more likely to be overweight using two different ways of measuring sugar intake.

Observational studies assessing whether total sugar intake is linked to obesity have had conflicting findings. Such studies usually ask people to report what they eat using food frequency questionnaires or a food diary, and then use this information to calculate sugar intake.

However, there is concern that people under-report their food intake. Therefore, the researchers in this study used both food diaries and an objective measure (the level of sugar in urine) to assess sugar intake. They wanted to see if there was any difference in results with the two approaches.

The main limitation of observational studies such as this is that it is difficult to prove that a single factor, such as a particular type of food, directly causes an outcome such as being overweight. This is because other differences between people may be affecting the results.

However, it would not be ethical to expose people to potentially unhealthy diets in a long-term randomised controlled trial, so this type of observational study is the best practical way of assessing the link between diet and weight.

What did the research involve?

Researchers recruited adults aged 39 to 79 in Norfolk in the UK. They took measurements including their body mass index (BMI), lifestyle information, and tested their urine for sugar levels. Participants were also asked to record their diet over seven days.

Three years later, the participants were invited back and measured again for BMI and waist circumference. Researchers looked for links between people's sugar levels as shown in urine samples, the amount of sugar they reported eating based on their diet records, and whether they were overweight at this three-year assessment.

The entire EPIC study included more than 70,000 people, but researchers took a single urine sample from around 6,000 people as a "spot check" biomarker on sugar levels.

These single spot check samples measured recent sugar intake, and may be a less reliable measure of overall sugar intake than the more expensive and difficult test of collecting urine over a 24-hour period for analysis.

Almost 2,500 people did not come back for the second health check, and 1,367 people's urine tests were either not possible to analyse or the results were outside the standard range and so discarded.

This means only 1,734 of the original sample could be included in the final analysis. Because the people finally included were not randomly selected, it's possible that their results are not representative of all the people in the study.

The researchers ranked both the urine sugar results and sugar based on the dietary record results into five groups, from lowest to highest sugar intake. The specific sugar they were assessing was sucrose, found in normal table sugar.

For the analyses of people's self-reported sugar intake based on dietary record, the researchers took into account how many calories each person ate so this did not affect the analysis.

They then looked at how well the two types of sugar consumption measurement compared, and how likely people at the five different levels of sugar consumption were to be overweight or obese after three years, based on their BMI and waist circumference.

What were the basic results?

Results showed a striking difference between the urine sugar measurements and the sugar intake based on the diet diaries.

People who had the highest levels of sugar in their urine were more likely to be overweight after three years than those with the lowest levels.

The reverse was true when researchers looked at the people whose diet diaries suggested they ate the most sugar relative to their overall calorie intake compared with the least.

Using the urine sugar measurement, 71% of people with the highest concentration were overweight three years later, compared to 58% of people with the lowest concentration.

This meant that having the highest urinary levels of sugar was associated with a 54% increase in the odds of being overweight or obese after three years (odds ratio [OR] 1.54, 95% confidence interval [CI] 1.12 to 2.12).

Using people's seven-day diet diaries, 61% of people who said they ate the most sugar relative to their overall calorie intake were overweight, compared to 73% of people who said they ate the least sugar.

This meant those who reported the highest sugar intake relative to their overall calorie intake were 44% less likely to be overweight or obese after three years (OR 0.56, 95% CI 0.40 to 0.77).

How did the researchers interpret the results?

The researchers conclude that, "Sucrose measured by objective biomarker, but not self-reported sucrose intake, is positively associated with BMI."

They say there are "several possible reasons" for the discrepancies between the methods used to assess sugar intake. They admit the spot check urinary sugar marker may have disadvantages, but conclude that under-reporting of foods with high sugar content, particularly among those who are overweight or obese, may be a contributing factor.

As a result, they say future researchers looking at sugar as part of diet should consider using an "objective biomarker" such as urinary sugar, rather than relying on people's own estimates of what they have consumed.

Conclusion

This study has found conflicting associations between an objective measure of sugar intake and a subjective measure of sugar intake based on food diaries, and the risk of a person becoming overweight.

While more sugar in urine samples was associated with a greater risk of becoming overweight, consuming more sugar (based on food diary records) was actually associated with a reduced risk.

If the urine biomarker is a more accurate reflection of sugar consumed than diet diaries, then this research may explain why some previous diet studies have failed to show a link between sugar and being overweight.

However, there are some limitations to consider with the urine biomarker. Because the test used was a one-off snapshot of sugar intake, it can only show us how much sugar was in the person's urine at the time they were tested. Similar to a short-term food diary, we don't know whether that is representative of their sugar consumption over time.

The urine test is also not able to measure very high or very low sugar levels. The analyses of urine sugar levels did not adjust for overall calorie intake, while those for self-reported sugar intake did. It would have been interesting to see whether the association between urinary sugar levels remained once calorie intake was taken into account.

The current study did not assess why the dietary records and urinary measures of sugar differed. It also did not assess whether the discrepancies were larger among people who were overweight or obese at the start of the study – only how these measures were related to the outcomes at the end.

So it is not possible to say from this study alone that people who were overweight or obese had greater discrepancies between what they reported eating and their urinary sugar measurements.

However, the authors report that other studies have shown overweight people, especially women, are prone to under-reporting diet, particularly between-meal snacks.

As with all observational studies, it is difficult to rule out that factors other than those being assessed might be having an effect on the results. The researchers adjusted their analyses for age and gender, and say that results "did not change materially" after they adjusted the figures to take account of people's physical activity levels.

The results do not appear to have been adjusted to take account of other factors, such as people's level of education, income or other components of their diet, which may have an effect on weight.

The effect of sugar on health, independent of calorie intake, is still being debated by health organisations. If the findings of the current study are correct, using objective measures of sugar intake could help assess its effect on obesity and more widely on health. 

 

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Obese people are 'in denial over how much sugar they eat': Huge gap exists between how much fat people think they consume and the reality, landmark study warns. Mail Online, March 16 2015

Links To Science

Kuhnlea GC, Tasevska N, Lentjes MA et al. Association between sucrose intake and risk of overweight and obesity in a prospective sub-cohort of the European Prospective Investigation into Cancer in Norfolk. The journal Public Health Nutrition. Published online February 2015

Categories: Medical News

Could epilepsy drug help treat Alzheimer's disease?

Medical News - Tue, 03/17/2015 - 13:37

A drug commonly used to treat epilepsy could help "slow down" the progress of Alzheimer's disease, reports The Daily Express. According to the news story, the drug levetiracetam was shown to "help restore brain function and memory". 

The story is based on a study analysing the short-term effect of the drug in 54 people with mild cognitive impairment (MCI). This is where people have problems with their memory and are at an increased risk of developing dementia, including Alzheimer's disease.

Dementia is a common condition that affects about 800,000 people in the UK. Most types of dementia cannot be cured.

Researchers found people with the condition showed overactivity in one part of the brain during one memory test involving image recognition.

This overactivity and performance on the test was better when participants had been taking 125mg of levetiracetam twice a day for two weeks, compared with when they had taken inactive "dummy" capsules.

This study was small, short-term and showed improvement on a single memory test. It is not possible to say from this study whether continuing to take the drug would reduce a person's chances of developing dementia.

Larger and longer-term trials would be needed to assess this. For now, levetiracetam remains a prescription-only medication that is only licensed for the treatment of epilepsy.

Where did the story come from?

The study was carried out by researchers from the Johns Hopkins University, and was funded by the US National Institutes of Health. It was published in the peer-reviewed medical journal NeuroImage: Clinical.

The Daily Express' headline, "Epilepsy drug found to slow down slide into Alzheimer's", overstates the findings of this study. It did not assess whether the drug affected a person's risk of Alzheimer's disease.

The study actually focused on how the drug affected short-term performance on one memory test in people with a specific type of MCI.

The news story also refers to "younger victims", but it is not clear what this means – the participants in this study were, on average, aged in their 70s.

What kind of research was this?

The main part of this study was a crossover randomised controlled trial looking at the effect of the anti-epileptic drug levetiracetam on brain function in people with amnestic mild cognitive impairment (aMCI). This type of study design is suitable if testing a drug or intervention that does not have lasting effects. 

The researchers report that previous studies have suggested people with aMCI have more activity in one part of one area of the brain (the dentate gyrus/CA3 region of the hippocampus) during certain memory tasks relating to recognising patterns.

Levetiracetam had been shown to reduce activity in these areas in animal research, so the researchers wanted to test whether low doses could reduce this excess activity and improve performance in memory tests in people with aMCI.

MCI is a decline in cognitive abilities (such as memory and thinking) that is greater than normal, but not severe enough to be classed as dementia. aMCI mainly affects a person's memory. A person with MCI is at an increased risk of developing dementia, including Alzheimer's disease.

What did the research involve?

The researchers recruited 69 people with aMCI and 24 controls (people of similar ages who did not have the condition). They gave levetiracetam to the people with aMCI and then tested their cognitive ability and monitored their brain activity with a brain scan (MRI).

They then repeated these tests with identical-looking dummy pills (placebo) and compared the results. They also compared the results with those of the controls taking the dummy pills.

All participants completed standard cognitive tests, such as the mini-mental status exam and other verbal and memory tests, as well as brain scans, at the start of the study.

Those with aMCI had to meet specific criteria – such as impaired memory, but without problems carrying out their daily activities – but not meet criteria for dementia. The control participants were tested to make sure they did not have MCI or dementia.

People with aMCI were randomly allocated to have either the levetiracetam test first and then the placebo test four weeks later, or the other way around. This aims to make sure that the order the tests were carried out does not affect the outcomes of the study.

In each test, participants took the capsules twice a day for two weeks before doing the cognitive test while having a brain scan. The researchers used three different doses of levetiracetam in their study (62.5mg, 125mg or 250mg, twice a day).

The cognitive test called the "three-judgement memory task" involved being shown pictures of common objects, such as a frying pan, beach ball, or a piece of luggage, shown one after the other.

Some of the pictures in the sequence were identical, some were similar but not identical (for example, different coloured beach balls), and most were unique pictures with no similar pictures shown.

The participants were asked whether each picture was new, identical to the one they had seen before, or similar to the one they had seen before. During the test, their brains were scanned using MRI to see which parts of the brain were active.

The researchers were able to analyse data from 54 people with aMCI and 17 controls, as some people dropped out of the study or did not have useable data – for example, if they moved too much while the brain scans were being taken.

What were the basic results?

After taking a placebo, people with aMCI tended to incorrectly identify more items as identical to ones they had seen before than control participants on the three-judgement memory task.

They identified fewer items as being similar to ones shown before compared with the control participants. This suggested people with aMCI were not as good at discriminating between items that were just similar to ones they had seen before and those that were identical.

When people with aMCI had been taking 62.5mg or 125mg of levetiracetam twice a day, they performed better on the three-judgement memory task than when they took placebo.

They correctly identified more items as being similar and fewer items incorrectly as similar, and performed similar to the controls. The highest dose of levetiracetam (250mg twice a day) did not improve test performance in people with aMCI.

Brain scans showed that when people with aMCI who had been taking placebo recognised identical items, they showed more activity in one area within a part of the brain called the hippocampus than controls recognising a match.

Taking 125mg of levetiracetam twice a day reduced this activity compared with placebo, but the lower and higher doses of levetiracetam did not.

The researchers say levetiracetam did not affect the performance of people with aMCI on standard neuropsychological tests. Results on these tests were not reported in detail.

How did the researchers interpret the results?

The researchers concluded that people with aMCI have overactivity of the dentate gyrus/CA3 region of the hippocampus during an image recognition memory task. Low doses of the epilepsy drug levetiracetam reduced this activity and improved performance on the tasks.

Conclusion

This small-scale study found that low doses of the epilepsy drug levetiracetam improved performance on an image recognition task for people with aMCI. This condition causes memory problems, and people who have it are at an increased risk of developing dementia.

While the news reporting has focused on the potential for levetiracetam to slow the onset of dementia, this is not something the research has assessed or focused on.

It instead focused on the short-term impact of the drug on a single test of memory, plus brain activity. There was reported to be no impact on other neuropsychological tests, which appeared to include other memory tests.

It's also important to note that the effect of taking the drug for two weeks was not lasting. It is not possible to say from this study whether continuing to take the drug would reduce a person's chances of developing dementia. Larger and longer-term trials would be needed to assess this. 

The researchers noted that they only looked at very specific brain areas, and this will not capture wider changes in brain networks.

Testing an existing drug that already has approval for treating another condition means that we already know it is safe enough for use in humans. This can mean that human trials can get started more quickly than if a completely new drug was being tested.

However, the benefits and risks still need to be weighed up for each new condition a drug is used for.

For now, levetiracetam remains a prescription-only medication that is only licensed for the treatment of epilepsy.

Analysis by Bazian. Edited by NHS ChoicesFollow Behind the Headlines on TwitterJoin the Healthy Evidence forum.

Links To The Headlines

Epilepsy drug found to slow down slide into Alzheimer's, study finds. Daily Express, March 14 2015

Links To Science

Bakker A, et al. Response of the medial temporal lobe network in amnestic mild cognitive impairment to therapeutic intervention assessed by fMRI and memory task performance. NeuroImage: Clinical. Published February 21 2015

Categories: Medical News

All teens should be vaccinated against rare strain of meningitis

Medical News - Mon, 03/16/2015 - 15:00

"A vaccination for meningitis is to be offered to all 14-18 year-olds in England and Wales, after a spike in a rare strain of the disease," The Guardian reports. The strain – meningitis W (MenW) – is described as rare, but life-threatening.

There has been a year-on-year increase in the number of meningitis cases caused by MenW since 2009, and infection has been associated with particularly severe disease and high fatality rates in teenagers and young adults. The increasing trend looks set to continue unless action is taken, so the government’s Joint Committee on Vaccination and Immunisation (JCVI), the body that advises on vaccination for England and Wales, has advised that immunisation against MenW should be routinely offered to all 14 to 18 year-olds.

 

What is meningitis?

Meningitis means inflammation (-itis) of the membrane (meninges) that covers the brain and spinal cord. It can be caused by infection with bacteria or viruses, but bacterial infection causes the most severe illness. The most common type of bacterial meningitis is meningococcal, caused by the bacteria Neisseria meningitidis. There are six main types of this bacterium – A, B, C, W, X and Y – with group B responsible for the majority of cases to date (over 90%).

Meningitis can cause different symptoms in different people, including:

  • fever with cold hands and feet
  • vomiting
  • severe headache
  • stiff neck
  • dislike of bright lights
  • tiredness
  • drowsiness
  • confusion
  • agitation
  • in some cases, convulsions or seizures

In babies, the soft spot on their head (fontanelle) may bulge. If infection spreads to the bloodstream (septicaemia), this can cause a non-blanching rash. This appears because the toxins released from the bacteria cause damage to the blood vessels, causing them to bleed.

Meningitis is a life-threatening medical emergency and requires immediate medical attention if suspected.

 

How many cases of MenW have there been?

Since 2009, Public Health England (PHE) reports a steady rise in the number of cases of meningitis caused by a particularly virulent W strain of meningitis. There were 22 cases in 2009, rising to 117 cases in 2014. In January 2015 alone, there were 34 confirmed cases in England, compared to 18 in January 2014, and nine in January 2013.

Andrew Pollard, Chair of JCVI, said: "We have seen an increase in MenW cases this winter, caused by a highly aggressive strain of the bug. We reviewed the outbreak in detail at JCVI and concluded that this increase was likely to continue in future years, unless action is taken. We have therefore advised the Department of Health to implement a vaccination programme for teenagers as soon as possible, which we believe will have a substantial impact on the disease and protect the public’s health."

 

When will the MenW vaccine be introduced?

The JCVI advises that immunisation against MenW should be offered to all 14 to 18 year-olds.

There is a quadrivalent MenACWY conjugate vaccine currently available that can give protection against MenW. However, this vaccine is currently not included in the UK’s immunisation schedule. It has, to date, only been recommended for groups at increased risk, including those with splenic dysfunction or who are travelling to certain parts of the world.

There doesn’t appear to be a set date for the introduction of the vaccine, but the Department of Health says it accepts JCVI’s advice on routine introduction of the vaccine and is now planning the implementation of a combined MenACWY immunisation programme.

John Watson, Deputy Chief Medical Officer for England, says on the PHE website: "We accept JCVI’s advice for an immunisation programme to combat this devastating disease. We are working with NHS England, PHE and the vaccine manufacturer to develop a plan to tackle the rising number of MenW cases."

Until the vaccine is introduced, remaining vigilant to the signs and symptoms of the disease will be the best form of protection.

As Dr Shamez Ladhani, Paediatric Infectious Disease Consultant at PHE, advises: "Meningococcal group W disease is a rare but life-threatening infection in children and adults. It’s crucial that we all remain alert to the signs and symptoms of the disease, and seek urgent medical attention if there is any concern. The disease develops rapidly ... be aware of all signs and symptoms – and don’t wait for a rash to develop before seeking urgent medical attention."

PHE is also reminding health professionals to be aware of the increase in MenW disease and to keep a high index of suspicion for this strain of the disease, across all age groups.

 

What other meningitis vaccines are currently available?

The current NHS immunisation programme offers protection against various other bacterial causes of meningitis.

The meningitis C vaccine is given as part of the childhood immunisation programme, with a routine booster jab given at ages 13 to 15 years. For non-vaccinated children and adults, like those going to university, they can also receive a single catch-up booster. Two decades ago meningitis C was responsible for a number of severe cases and deaths, particularly among adolescents and young adults at college. Introduction of the meningitis C vaccine in 1999 caused a big fall in the number of cases caused by this bacterium.

A new meningitis B vaccine was introduced last year, and the JCVI also recommended this is given as part of the child immunisation programme. However, there are still some cost-effectiveness issues to be resolved before it is routinely offered. There are also no current plans for this to be given as a booster jab in adolescence or young adulthood.

Protection against other non-meningococcal bacterial causes of meningitis is also given through the routine child immunisation programme. These are:  

  • the MMR vaccine
  • the 5-in-1 vaccine – which provides protection against diphtheria, tetanus, whooping cough (pertussis), polio and Hib (Haemophilus influenzae type b)
  • the pneumococcal vaccine

Regardless of immunisation status, as PHE advises, being vigilant to possible signs and symptoms of meningitis is the best protection against this potentially life-threatening disease.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Meningitis vaccine to be offered to teenagers between 14 and 18. The Guardian, March 13 2015

Over three million teenagers to be vaccinated against 'virulent' new Meningitis strain. The Independent, March 13 2015

Jabs drive to combat new deadly strain of meningitis after a number of cases rise by 431%. Mail Online, March 14 2015

All UK teenagers 'should be vaccinated' against aggressive meningitis strain. The Daily Telegraph, March 13 2015

Meningitis vaccine plan after steep rise in new strain. BBC News, March 13 2015

Links To Science

Public Health England. Meningococcal group W (MenW) immunisation advised for 14 to 18 year-olds (Press Release). March 13 2015

Categories: Medical News

Does light at night pose a health risk?

Medical News - Mon, 03/16/2015 - 03:00

"Britons should fit blackout blinds and ban electronic gadgets from the bedroom to avert the risk of diseases such as cancer," the Mail Online warns.

This alarmist advice is prompted by a review looking at the theory that electrical light at night disrupts our normal body block and could therefore pose a risk to our health.  

In the review, researchers looked at various studies, including research linking night-shift work with breast or colon cancer, and light levels in the bedroom being linked to depression and obesity.

As the authors of this review acknowledge, the main problem with this type of evidence is that much of it is circumstantial, and may be influenced by bias and confounding from other factors.

Another drawback is this study does not appear to be systematic. The researchers provide no methods for how they identified the studies they discuss, and we do not know that all relevant studies have been included.

This effectively makes the review an opinion piece, albeit with lashings of supporting evidence. This means there is the risk that the authors have cherry-picked evidence that backs up their claims, while ignoring research that doesn't fit in with their theories.

The potentially large public health impact of even a small increase in disease risk linked with light at night seems worthy of further study. But this study doesn't prove that light at night harms our health.

Regardless, getting a good night's sleep is important. Read more about how to have a restful night.

 

Where did the story come from?

This opinion piece was written by two researchers from the University of Connecticut and Yale University in the US, and was jointly funded by the two universities.

It was published in the peer-reviewed Philosophical Transactions B on an open-access basis, so it is free to read online or download as a PDF.

The Mail appears to have taken the study at face value, recommending that Britons need to use blackout blinds on their windows, and clearly hasn't considered some of the drawbacks of this particular piece of research.

Because this wasn't a systematic review, we can't be certain that the studies used to inform the authors' conclusions are representative of the literature on the subject, and could also be of questionable quality. 

 

What kind of research was this?

This was an evidence-informed opinion piece, or narrative review, where the researchers discussed the theory that electrical light, especially at night, disrupts our normal body block. They consider whether this poses a risk to our health.

This narrative discussion is referenced throughout, but no methods are provided. It does not appear to be a systematic review, where researchers search all the available evidence to identify studies related to the issue of the effects that electrical light may have on the body clock.

This means we do not know that all the relevant studies related to this issue have been identified. As such, this review must largely be considered to be an article outlining the researchers' opinions, as informed by the evidence they looked at.

 

What do the researchers discuss?

The researchers present sleep deprivation or disruption at night as a result of exposure to electrical light as being a burden of modern life.

While they say light at night has been linked to sleep disruption, "What has not been 'proven' is that electric light at night causally increases risk of cancer, or obesity, or diabetes, or depression."

They say these links are plausible given that disturbed sleep can have an effect on cellular processes and DNA repair. The problem, they say, is that much of the evidence linking disturbed sleep and light at night to these diseases is circumstantial. They then describe what this circumstantial evidence looks like.

 

What do they say about light at night and disease risk?

The researchers discuss the issue of light at night and disease risk, supported by various studies.

They first discuss studies that have linked night-shift work in women with an increased risk of breast cancer, thought to possibly be a result of the influence of melatonin on oestrogen levels.

Melatonin is a sleep hormone, while high oestrogen levels are linked to breast cancer development.

Similarly, a handful of studies have linked shift work or sleep disruption with bowel cancer in both sexes, and with prostate cancer in men, as discussed in our special report on shift working and health last year.

But the researchers fail to mention that these studies may be influenced by various confounders.

The International Agency for Research on Cancer (IARC) currently defines the confidence that something may cause cancer as:

  • 1 – human carcinogen
  • 2a – probable carcinogen
  • 2b – possible carcinogen
  • 3 – inadequate evidence
  • 4 – probably not a carcinogen

In 2007 the IARC classified shift work that involves circadian disruption as a class 2a probable carcinogen, putting it in a category alongside anabolic steroids, vinyl fluoride and mustard gas.

This categorisation was based on a "compelling animal model", but limited epidemiological studies, where signs were consistent with a causal relationship but probably influenced by bias and confounding.

The researchers then discuss other observational studies linking light level in the bedroom (either self-reported or measured) with depression and obesity risk.

They acknowledge a risk of bias and confounding in these studies, but say that, "If these reported associations are causal, then there would be obvious and easy interventions, such as to use black-out shades and elimination of all light sources in the bedroom, no matter how minute."

The researchers go on to present other small experimental studies where participants were exposed to different amounts of light at night. The effects on body chemicals were then measured, including the sleep chemical melatonin.

Some of the broad conclusions were:

  • blue light has the greatest effect upon sleep disruption; red the least
  • there is a dose-response relationship
  • light exposure during the day influences night-time sensitivity
  • individuals have different levels of sensitivity to light
  • even through closed eyelids, a very bright light can suppress melatonin levels

The researchers go on to discuss the possible effect light has on genes involved in the control of the body clock, and how these could potentially be linked to cancer.

 

How did the researchers interpret the results?

In response to their overall question of whether electrical light exposure at night is a risk factor for our health, the researchers say this "cannot yet be answered with assurance, but is important to ask".

They say that, "It must be stressed that there is ample evidence for the disruptive effect of electric light on physiology in short-term experiments in humans.

"There is some epidemiologic evidence on the long-term impact on disease, but this evidence is not yet adequate to render a verdict."

However, they stress this is "an urgent issue given the increasing pervasiveness of electric lighting in our built environment."

 

Conclusion

This opinion piece discusses the evidence related to whether exposure to electrical light night is a health risk.

Much of the article considers various experimental studies where small numbers of participants were exposed to different light levels at night, as well as observational studies reportedly linking night-shift work with cancer, including breast and colon cancer.

The researchers also identified some studies linking self-reported or measured light in the bedroom with depression and obesity.

But this study has two prominent limitations. It does not appear to have been a systematic review. No methods are provided, and we do not know whether the researchers have searched the entire global literature on the subject to identify all relevant studies.

We also do not know whether studies linking light at night with disease could have been preferentially discussed as examples, while other studies that did not find any links were either not identified or not discussed in this review.

As such, this review must largely be considered to be the opinion of the researchers as informed by the evidence they looked at.

The second limitation is the strength and quality of the evidence linking light exposure at night to disease.

Most of the experimental studies discussed, where people were exposed to different light levels at night, were very small (one included 12 people, another eight).

These results are specific to the small sample included. This means they may be heavily biased and confounded by the characteristics of the participants, and therefore not apply to wider populations.

The small sample size may also fail to identify any real differences because of a lack of statistical power.

And just measuring body chemicals after a couple of nights of artificially manipulated light levels may not give us reliable evidence of health effects that would be seen with longer-term patterns.

Much of the evidence looked at is also circumstantial and based on observational studies. Though the design and quality of these underlying studies was not examined as part of this appraisal, it is likely the studies may be subject to various sources of bias or confounding, making it difficult to establish direct cause and effect.

The IARC study reportedly classified shift work that involves circadian disruption as a probable carcinogen. But the organisation acknowledged that this is based on limited epidemiological studies that may have been influenced by bias and confounding factors.

Overall, the possible links between electrical light exposure at night and disease is definitely worthy of further study. But, for now, people should not be overly alarmed by these findings and feel the need to rush out to buy blackout blinds for their bedroom windows.

That said, creating a calming environment in your bedroom, free from visual and audio distractions, can enhance the quality of your sleep.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Cancer warning over lights in the bedroom: Fit blackout blinds and ban gadgets to avert disease, say experts. Mail Online, March 16 2015

Links To Science

Stevens RG, Zhu Y. Electric light, particularly at night, disrupts human circadian rhythmicity: is that a problem? Philosophical Transactions B. Published online March 16 2015

Categories: Medical News

Do people with depression perceive time differently?

Medical News - Fri, 03/13/2015 - 14:00

"How depression affects our sense of time: Hours drag on and even stand still," is the somewhat over-hyped headline from the Mail Online.

As the old saying goes – Time flies when you’re having fun. So does the reverse also ring true? Does feeling depressed slow down your perception of time? Two German researchers tried to find out.

They pooled the results of previous studies, which lead to 433 depressed people being compared with 485 non-depressed people. The results tentatively suggest that some people with depression may perceive time as going more slowly than those without.

No difference was found in their ability to estimate actual time durations in tests (for example, trying to judge when a minute had passed).

The study has a number of limitations, meaning we should be cautious in assuming that the findings are reliable. Their statistical methods, for example, made it more likely to find a statistically significant result by chance and they noted that using other methods would have wiped out any differences between the groups.

The clinical implications of this potential time perception difference are also unclear. Can knowing that people with depression perceive time as progressing slowly help their care or support?

The study provides little in the way of answers, but may stimulate useful debate.

 

Where did the story come from?

The study was carried out by researchers from Johannes Gutenberg-Universität Mainz, Germany, who report receiving no external funding for the work.

The study was published in the peer-reviewed Journal of Affective Disorders.

The Mail Online reported the story at face value and did not discuss any of its limitations. Its choice of headline, "Hours drag on and even stand still", is an exaggeration of the findings.

It included interviews with the study authors, who said their results confirmed anecdotal reports from hospital and private practice staff that: "depressed patients feel that their time only creeps forward slowly or is passing in slow motion". Anecdotal reports, while interesting, are not evidence.

 

What kind of research was this?

This was a meta-analysis pooling the results of studies looking at time perception of people with depression.

The study authors say that "depressive patients frequently report to perceive time as going by very slowly", but previous studies on the topic have given inconsistent results. They wanted to pool the past results to see if there was any overall effect. This pooling of many independent studies is called a meta-analysis.

A meta-analysis is an appropriate and potentially powerful way of studying the issue. However, the meta-analysis is only as good as the studies feeding it.

 

What did the research involve?

The team pooled the results from 16 individual studies in which 433 depressed people (cases) and 485 non-depressed people (controls) participated. The main analysis looked for differences in measures of time perception between the two groups.

To identify as much relevant material as possible, the researchers searched for published evidence online (using a Web of Science search) and called for unpublished information to be submitted by more than 100 experts in the field.

Studies were only included if they were in adults, had a control group of non-depressed people, had diagnosed depression using standardised criteria, and had sufficient statistical information to enable the pooling of estimates.

In the included studies, the participants were asked to estimate the duration of periods of time.

For example, they were asked to estimate the length of a film in minutes, press a button for five seconds, or discriminate the duration of two sounds. Studies measured time durations ranging from the ultra-short (less than a second) to the long (greater than 10 minutes).

They were also asked about their perception of whether time flowed quickly or slowly. This typically used visual scales, requiring the participant to mark a point on a line ranging from very fast to very slow.

 

What were the basic results?

The main results showed that people with depression were no different than people without at judging time duration.

However, the subjective perception of how time flowed did differ between the groups. People with depression perceived time as going more slowly than those without.

In effect, this meant that both groups could estimate time to the same accuracy, but the people with depression perceived the time to be passing much more slowly.

 

How did the researchers interpret the results?

The team concluded: "Depression has medium effects on the subjective flow of time, whereas duration judgments basically remain unaffected."

 

Conclusion

Having compared 433 depressed people with 485 non-depressed people, the study suggests that some people with depression perceive time as going more slowly than those without. No difference was found in their ability to actually estimate duration of time on testing, but people with depression rated time generally as flowing more slowly.

People with low mood often have associated feelings of little enjoyment in daily life and normal activities, and feelings of being hopeless or helpless. As such, the idea that they may perceive time as passing by more slowly seems plausible, and point to a possible phenomenon to be investigated further. However, the findings do not prove this outright. The study authors themselves advised caution when interpreting the findings. For example, the results weren’t able to take account of any influence of the use of medications or treatments for depression, such as psychotherapy. These could potentially influence time perception.

More importantly, their use of statistical methods made it more likely to find a statistically significant result by chance. They note that by using other methods, none of their findings would have reached statistical significance.

The clinical implications of this time perception are also unclear. Can knowing that people with depression perceive time as progressing slowly help their care or support?

As a result, it would be beneficial to see more robust research in this area before believing this is a widespread occurrence, and a clearer rationale for its importance.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

How depression affects our sense of time: Hours drag on and even stand still for those battling the condition, study reveals. Mail Online, March 12 2015

Links To Science

Thönes S, Oberfeld D. Time perception in depression: A meta-analysis. Journal of Affective Disorders. Published online January 14 2015

Categories: Medical News

Loneliness 'increases risk of premature death'

Medical News - Fri, 03/13/2015 - 13:31

"Loneliness as big a killer as obesity and as dangerous as heavy smoking," the Daily Express reports. Researchers pooled the results of previous studies, estimating that loneliness can increase the risk of premature death by around 30%.

The headline follows a new analysis of more than 3.4 million participants, which showed evidence that people who feel, or are, socially isolated or live alone are at about a 30% higher risk of early death.

The study has many strengths: its large sample size, adjustment for initial health status, and use of prospective studies being the main three. This provided some evidence that the isolation was causing ill health, rather than the other way round, but we can't be certain.

Causation bias could still be a factor in some cases – in other words, people with a chronic disease are less likely to socialise with others. This makes it difficult to nail down cause and effect.

The results of this study remind us that health has a strong social element and is not merely physical. Connecting with others can improve both mental and physical wellbeing.

 

Where did the story come from?

The study was carried out by researchers from Brigham Young University in the US and was funded by grants from the same university.

It was published in the peer-reviewed journal, Association for Psychological Science.

The UK media generally covered the study accurately. Many news sources based their reporting on an assertion made by the lead author, Julianne Holt-Lunstad, who said the harmful effects of loneliness are akin to the harm caused by smoking, obesity or alcohol misuse.

Professor Holt-Lunstad was quoted in the Daily Mail as saying that, "The effect is comparable to obesity, something that public health takes very seriously ... we need to start taking our social relationships more seriously."

This assertion appears to be based on a previous study carried out by Professor Holt-Lunstad published in 2010. We were not able to appraise this study, so we cannot comment on the accuracy of this comparison. The 2010 research was published in the online journal PLOS One.

 

What kind of research was this?

This was a systematic review and meta-analysis investigating whether loneliness, social isolation, or living alone affects your chances of dying early.

The researchers say there are many lifestyle and environmental factors that increase our risk of dying early, such as smoking, being inactive and air pollution.

However, they say much less attention is paid to social factors, despite evidence they may carry an equal or greater influence on early death.

This study wanted to be the first to quantify the influence of loneliness and social isolation on early death.

 

What did the research involve?

The researchers searched online databases for studies reporting numerical data on deaths affected by loneliness, social isolation, or living alone. They then pooled all the studies to calculate the overall effect.

The literature search included relevant studies published between January 1980 and February 2014. These were identified using the online databases MEDLINE, CINAHL, PsycINFO, Social Work Abstracts, and Google Scholar.

Loneliness and social isolation were defined objectively and subjectively:

  • social isolation (objective) – pervasive lack of social contact or communication, participation in social activities, or having a confidant (example measure: Social Isolation Scale or Social Network Index)
  • living alone (objective) – living alone versus living with others (example measure: answer to a yes/no question on living alone)
  • loneliness (subjective) – feelings of isolation, disconnectedness and not belonging (example measure: University of California, Los Angeles Loneliness Scale)

Some studies made no adjustment for potential confounders. Others controlled for just a few variables (partial adjustment), usually age and gender.

A final group adjusted for several factors (fully adjusted), such as measures relevant to depression, socioeconomic status, health status, physical activity, smoking, gender and age.

Sensibly, the researchers presented separate results for the different categories of adjustment to see to what extent the results were potentially influenced by the confounders.

The bigger studies counted more towards the meta-analysis than the smaller ones – a "weighted" effect size.

 

What were the basic results?

In total, the study analysed 70 independent prospective studies containing more than 3.4 million participants followed for an average of seven years. Overall, the researchers found social isolation resulted in a higher likelihood of death, whether measured objectively or subjectively.

Pooling the best studies – those with full adjustment for confounding – showed the increased likelihood of death was 26% for reported loneliness, 29% for social isolation, and 32% for living alone. All were statistically significant increases compared with those reporting less loneliness or social isolation.

The researchers found no differences between measures of objective and subjective social isolation, and the results remained consistent across gender, length of follow-up and world region.

However, initial health status influenced the findings, as did participant age. For example, social deficits were more predictive of death in people under the age of 65 than over 65.

 

How did the researchers interpret the results?

The researchers said that, "Substantial evidence now indicates that individuals lacking social connections (both objective and subjective social isolation) are at risk for premature mortality.

"The risk associated with social isolation and loneliness is comparable with well-established risk factors for mortality, including those identified by the US Department of Health and Human Services (physical activity, obesity, substance abuse, responsible sexual behaviour, mental health, injury and violence, environmental quality, immunisation, and access to health care)."

They say there is mounting evidence that social isolation and loneliness are increasing in society, so it would be prudent to add social isolation and loneliness to lists of public health concerns.

 

Conclusion

This meta-analysis of more than 3.4 million participants indicates social isolation, living alone and loneliness are linked with about a 30% higher risk of early death.

The study has many strengths, including its huge sample size, adjustment for initial health status, and use of prospective studies.

This provided some evidence that the isolation was causing ill health, rather than the other way round, but we can't be certain. Poor health can lead to loneliness and social isolation and vice versa, so cause and effect are tricky to nail down.

The researchers believe the study of the effects of loneliness and social isolation is currently at the stage that research into the risks of obesity was decades ago. They have identified a problem and predict it will increase in years to come.

The findings also challenge assumptions. The study team said that, "The data should make researchers call into question the assumption that social isolation among older adults places them at greater risk compared with social isolation among younger adults [who may be at risk of alcohol and drug misuse, as well as suicide].

"Using the aggregate data, we found the opposite to be the case. Middle-age adults were at greater risk of mortality when lonely or living alone than when older adults experienced those same circumstances."

The results of this study remind us all that psychosocial and emotional feelings can be just as relevant to our overall health and wellbeing as physical factors. Read more about how how connecting with others can improve wellbeing and find out how to overcome feelings of loneliness.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Loneliness as big a killer as obesity and as dangerous as heavy smoking. Daily Express, March 12 2015

How loneliness leads to an early grave: Feeling alone 'shortens lifespan as much as obesity'. Mail Online, March 12 2015

Links To Science

Holt-Lunstad J, Smith TB, Baker M, et al. Loneliness and Social Isolation as Risk Factors for Mortality - A Meta-Analytic Review. Perspectives on Psychology. Published online March 11 2015

Categories: Medical News