Medical News

No proof orange juice boosts brain power

Medical News - Mon, 05/18/2015 - 16:00

"Drinking orange juice every day could improve brain power in the elderly, research shows," the Mail Online reports. Despite the encouraging words from the media, the small study this headline is based on does not provide strong evidence that an older person would see any noticeable difference in their brain power if they drink orange juice for two months.

The study involved 37 healthy older adults, who were given orange juice or orange squash daily for eight weeks before switching to the other drink for the same amount of time. The 100% orange juice contains more flavonoids, a type of plant compound that has been suggested to have various health benefits.

The researchers gave participants a whole battery of cognitive tests before and after each eight-week period. Both drinks caused very little change on any of the test results and were not significantly different from each other on any of the tests individually.

The researchers also carried out analyses where they combined the test results and looked at the statistical relationships between the drink given and when the test was given. On this occasion, they did find a significant result – overall cognitive function (the pooled result of all the tests combined) was better after the juice than after the squash.

But the overall pattern of the results doesn't seem very convincing. This study does not provide conclusive evidence that drinking orange juice has an effect on brain function.  

Where did the story come from?

The study was carried out by researchers from the University of Reading, and was funded by Biotechnology and Biological Sciences Research Council grants and the Florida Department of Citrus, also known as Florida Citrus.

Florida Citrus is a government-funded body "charged with the marketing, research and regulation of the Florida citrus industry", a major industry in the state. Florida Citrus was reported to have helped design the study.

The study was published in the peer-reviewed American Journal of Clinical Nutrition.

The Mail Online took the study at face value without subjecting it to any critical analysis. Looking into the research reveals rather unconvincing evidence that drinking orange juice would have any effect on a person's brain function.  

What kind of research was this?

This was a randomised crossover trial that aimed to compare the effects of 100% orange juice, which has high flavanone content, and orange-flavoured cordial, which has low flavanone content, on cognitive function in healthy older adults.

Flavonoids are pigments found in various plant foods. It has been suggested they have various health benefits – for example, some studies have suggested that high consumption of flavonoids can have beneficial effects on cognitive function. Flavanones are the specific type of flavonoids found in citrus fruits. This trial investigated the effect of flavanones in orange juice.

This was a crossover trial, meaning the participants acted as their own control, taking both the high and low flavanone content in random order a few weeks apart. The crossover design effectively increases the sample size tested, and is appropriate if the interventions are not expected to have a lasting impact on whatever outcome is being tested. 

What did the research involve?

The study recruited 37 older adults (average age 67) who were given daily orange juice or orange squash for eight weeks in a random order, with a four-week "washout" period in between. They were tested to see whether the drinks differed in their effect on cognitive function.

All participants were healthy, without significant medical problems, did not have dementia and had no cognitive problems. In random order, they were given:

  • 500ml 100% orange juice containing 305mg natural flavanones daily for eight weeks
  • 500ml orange squash containing 37mg natural flavanones daily for eight weeks

The drinks contained roughly the same calories. The participants were not told which drink they were drinking, and the researchers assessing the participants also did not know.

Before and after each of the eight-week periods, participants visited the test centre and had data collected on height, weight, blood pressure, health status and medication. They also completed a large battery of cognitive tests assessing executive function (thinking, planning and problem solving) and memory.

The researchers analysed change in cognitive performance from baseline to eight weeks for each drink, and compared the effects of the two drinks. 

What were the basic results?

On the whole, the two drinks caused very minimal change from baseline on any of the individual tests. There was no statistically significant difference between the two drinks when comparing score change from baseline on any of the tests individually.

There was only a single significant observation when looking at the individual tests at the end of treatment (rather than change from baseline). A test of immediate episodic memory was higher eight weeks after drinking 100% orange juice compared with squash (score 9.6 versus 9.1). However, when this was compared to the change from baseline, it didn't translate into any significant difference between the groups.

The researchers also carried out a statistical analysis looking at the interactions between the drink given and the testing occasion. In this analysis, they did find an interaction between the drink and testing for global cognitive function (when all test results were combined). This showed that, overall, this was significantly better at the eight-week visit after the orange juice intake. 

How did the researchers interpret the results?

The researchers concluded that, "Chronic daily consumption of flavanone-rich 100% orange juice over eight weeks is beneficial for cognitive function in healthy older adults."

They further say that, "The potential for flavanone-rich foods and drinks to attenuate cognitive decline in ageing and the mechanisms that underlie these effects should be investigated." 

Conclusion

Overall, this small crossover study does not provide conclusive evidence that drinking orange juice has an effect on brain function.

A wide variety of cognitive tests were performed in this study before and after the two drinks (orange juice and squash). The individual test results do not indicate any large effects. Notably, both drinks caused very little change from baseline on any of the test results, and were not significantly different.

The only significant results were found for overall cognitive function when combining test results and looking at statistical interactions. The fact a consistent effect wasn't seen across individual measures and the different analyses means the results are not very convincing.

The trial is also quite small, including only 37 people. These participants were also a specific sample of healthy older adults who volunteered to take part in this trial, and none of them had any cognitive impairment, so the results may not be applicable to other groups.

While the participants were not told what they were drinking and the drinks were given in unlabelled containers, they did have to dilute them differently. This and the taste of the drinks may have meant the participants could tell the drinks apart. The researchers did ask participants what they thought they were drinking, and although about half said they did not know, most of those who gave an opinion (16 out of 20) got it right.

There is also only comparison of high- and low-flavanone orange juice. There is no comparison with a flavanone-free drink, or foods or drinks that contain other types of flavonoid.

The possible health benefits of flavonoids or flavanones specifically will continue to be studied and speculated. However, this study can't conclusively tell us that they have an effect on brain power.

A good rule of thumb is what's good for the heart is also good for the brain – taking regular exercise, eating a healthy diet, avoiding smoking, maintaining a healthy weight, and drinking alcohol in moderation.

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

Links To The Headlines

Two daily glasses of orange juice 'boosts elderly brainpower': Significant improvements can be seen in less than two months, research shows. Mail Online, May 16 2015

Orange juice 'improves brain function'. The Daily Telegraph, May 15 2015

Links To Science

Kean RJ, Lamport DJ, Dodd GF, et al. Chronic consumption of flavanone-rich orange juice is associated with cognitive benefits: an 8-wk, randomized, double-blind, placebo-controlled trial in healthy older adults. The American Journal of Clinical Nutrition. Published online January 14 2015

Categories: Medical News

Drug combination for cystic fibrosis looks promising

Medical News - Mon, 05/18/2015 - 15:00

"A 'groundbreaking' new therapy for cystic fibrosis could hugely improve patients' quality of life," The Daily Telegraph reports after a combination of two drugs – lumacaftor and ivacaftor – was found to improve lung function.

The headline is prompted by a trial looking at a new treatment protocol for cystic fibrosis, a genetic condition caused by a mutation in a gene that normally creates a protein that controls salt balance in a cell. This leads to thick mucus build-up in the lungs and other organs, causing a persistent cough, poor weight gain and regular lung infections.

The prognosis for cystic fibrosis has improved dramatically over the past few decades, but the condition is still life-limiting. This new drug combination works together to make the faulty cell protein work better.

More than 1,000 people with cystic fibrosis were given the new protocol or a placebo for 24 weeks. The treatment led to meaningful improvements in lung function compared with the placebo. It also reduced the number of lung infections, improved quality of life, and helped people gain weight.

Further study of the drugs' effects in the longer term will be needed, in addition to collecting more information on side effects.

But this treatment won't work for all people with cystic fibrosis. There are various gene mutations, and this treatment only targeted the most common one, which affects half of people with the condition.  

Where did the story come from?

The study was carried out by researchers from various international institutions, including the University of Queensland School of Medicine in Australia, and Queens University Belfast.

There were various sources of funding, including Vertex Pharmaceuticals, which makes the new treatment.

The study was published in the peer-reviewed New England Journal of Medicine.

The UK media provided balanced reporting of the study, including cautions that the treatment should work in around half of people with cystic fibrosis. Researchers were quoted as saying that although they hope this could improve survival for people with cystic fibrosis, they don't know this for sure.

However, some of the reporting focusing on the quality of life improvements does not take note of the researchers' caution that, overall, these improvements fell short of what was considered meaningful.

The media also debated the cost of the treatment protocol. The Guardian reports one year's course of lumacaftor alone costs around £159,000. The new treatment protocol is being assessed by the National Institute for Health and Care Excellence (NICE) to see if it is a cost effective use of resources.  

What kind of research was this?

This was a randomised controlled trial (RCT) aiming to investigate the effects of a new treatment for cystic fibrosis.

Cystic fibrosis is a hereditary disease caused by mutations in a gene called cystic fibrosis transmembrane conductance regulator (CFTR). The protein made by the CFTR gene affects the balance of chloride and sodium inside the cells.

In people with cystic fibrosis, the CFTR protein does not work. This causes mucus secretions in the lungs and other parts of the body to be too thick, leading to symptoms such as a persistent cough and frequent chest infections.

There is no cure for cystic fibrosis, and current management focuses on breaking down mucus and controlling the symptoms with treatments such as physiotherapy and inhaled medicines.

We have two copies of all of our genes – one inherited from each parent. To develop cystic fibrosis, you need to inherit two abnormal copies of the CFTR gene. One in 25 people carry a copy of the abnormal CFTR gene. If two people carrying an abnormal gene have a child and the child receives the abnormal gene from both parents, they will develop cystic fibrosis.

This trial looked at the effects of a treatment that helps the abnormal CFTR protein work better, called lumacaftor. It was tested in combination with another treatment called ivacaftor, which also boosts the activity of CFTR proteins.

There are various different types of CFTR gene mutations. One, called Phe508del, is the most common and affects 45% of people with the condition. Lumacaftor specifically corrects the abnormality caused by the Phe508del mutation, so this trial only included people with this mutation. An RCT is the best way of examining the safety and effectiveness of a new treatment. 

What did the research involve?

This study reports the pooled results of two identical RCTs that have investigated the effects of two different doses of lumacaftor, in combination with ivacaftor, for people with cystic fibrosis who have two copies of the Phe508del CFTR mutation.

The study recruited 1,122 people aged 12 or older; 559 in one of the trials and 563 in the other. Participants in both trials were randomly assigned to one of three study groups:

  • 600mg of lumacaftor every 24 hours in combination with 250mg of ivacaftor every 12 hours
  • 400mg of lumacaftor every 12 hours in combination with 250mg of ivacaftor every 12 hours
  • placebo pills every 12 hours

The placebo pills looked just like the lumacaftor and ivacaftor pills and were taken in the same way, so researchers and participants could not tell whether they were taking placebo or not. All treatments were taken for 24 weeks.

The main outcome examined was how well the participants' lungs worked, measured as a change in percentage of predicted forced expiratory volume (FEV1). This is the amount of air that can be forcibly exhaled in the first second after a full in-breath, which provides a well-validated method of assessing lung health and function.

The percentage of predicted FEV1 shows how much you exhale as a percentage of what you would be expected to, based on your age, sex and height.

The researchers also looked at the change in body mass index (BMI) and in people's quality of life in terms of their lung function, as reported in the patient-reported Cystic Fibrosis Questionnaire – Revised (CFQ-R).

The study analysis included all patients who received at least one dose of the study drug, which was 99% of all participants.  

What were the basic results?

At the start of the study, the average FEV1 of participants was 61% of what was predicted (what it ought to be). There were no differences between the randomised groups in terms of age, sex, lung function, BMI or current cystic fibrosis treatments used.

Lumacaftor-ivacaftor significantly improved how well the participants' lungs worked compared with placebo in both trials, and at both doses. The change in percentage of predicted FEV1 ranged between 2.6% and 4.0% across the two trials compared with placebo over the 24 weeks.

There were also significant improvements compared with placebo in BMI (range of improvement 0.13 to 0.41 units), and respiratory quality of life (1.5 to 3.9 points on the CFQ-R). There was also a reduced rate of lung infections in the treatment groups.

There was similar reporting of side effects across the two treatment groups and placebo groups (around a quarter of participants experienced side effects). The most common adverse effect participants experienced was lung infections.

However, the proportion of participants who stopped taking part in the study as a result of side effects was slightly higher among the drug treatment groups (4.2%) compared with placebo groups (1.6%).

The specific reasons for discontinuation varied between individuals – for example, a couple stopped because of shortness of breath or wheezing; some stopped because of blood in their sputum; some because of a rash; and so on. 

How did the researchers interpret the results?

The researchers concluded that, "These data show that lumacaftor in combination with ivacaftor provided a benefit for patients with cystic fibrosis [who carried two copies of] the Phe508del CFTR mutation." 

Conclusion

This trial has demonstrated that this new treatment combination could be effective in improving lung function for people with cystic fibrosis who have two copies of the common Phe508del CFTR mutation.

The trial has many strengths, including its large sample size and the fact it captured outcomes at six months for almost all participants. The improvements in lung function were seen while the participants continued to use their standard cystic fibrosis treatments. As the researchers suggest, this indicates the treatment could be a beneficial add-on to normal care to further improve symptoms.

The results seem very promising, but there are limitations that should be addressed. Though lung function improvements were said to be clinically meaningful, improvements in quality of life relating to lung function fell short of what is considered to be meaningful clinically (four points and above on the CFQ-R scale).

The trial only included people with well-controlled cystic fibrosis, and effects of the treatment might not be as good for people with poorer disease control. The treatment combination would also only be suitable for people with the Phe508del CFTR mutation.

This trial only included people with two copies of this mutation, which is only the case in around 45% of people with the condition. Whether the treatment would benefit people who carry one copy of the Phe508del mutation and a different second CFTR mutation is not yet clear, and people with two non-Phe508del mutations would not be expected to benefit from this treatment.

The effects of this treatment combination will need to be studied in the longer term, beyond six months – for example, to see whether it could prolong life. Further information will need to be collected on side effects and how commonly they cause people to stop treatment.

Though this treatment targets the abnormal protein that causes symptoms, as one of the study authors notes in The Guardian, it is not a cure. The lead researcher, Professor Stuart Elborn, was quoted as saying: "It is not a cure, but it is as remarkable and effective a drug as I have seen in my lifetime."

Overall, the results of this trial show promise for this new treatment for people with cystic fibrosis who carry two copies of this specific gene mutation.

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

Links To The Headlines

'Groundbreaking' new treatment for cystic fibrosis. The Daily Telegraph, May 17 2015

Cystic fibrosis treatment found to improve lives of sufferers in trials. The Guardian, May 17 2015

Cystic fibrosis drug offers hope to patients. BBC News, May 17 2015

New treatment brings hope on cystic fibrosis: Thousands of patients could have lives transformed by new drug for most common form of the condition. Mail Online, May 18 2015

Links To Science

Wainwright CE, Elborn JS, Ramsey BW, et al. Lumacaftor–Ivacaftor in Patients with Cystic Fibrosis Homozygous for Phe508del CFTR. The New England Journal of Medicine. Published online May 17 2015

Categories: Medical News

Does holding your breath during an injection make it less painful?

Medical News - Fri, 05/15/2015 - 15:00

"Hate injections? Holding your breath can make the pain of jabs more bearable," the Mail Online reports. A team of Spanish researchers mechanically squeezed the fingernails of 38 willing volunteers to cause them pain.

For one round of experiments, the group were told to hold their breath before and during the pain squeeze. In the second round, they had to breathe in slowly while the pain was applied. Those holding their breath reported slightly lower pain ratings overall than those breathing in slowly.

The hypothesis underpinning this technique is that holding your breath increases blood pressure, which in turn reduces nervous system sensitivity, meaning you have a reduced perception of any pain signals.

But before you try this out, it's worth saying the pain perception differences were very small – a maximum 0.5 point difference on a scale from 0 to 10.

Also, the pain scores of the experimental breathing styles weren't compared with normal breathers, so we don't actually know if they were beneficial overall at reducing pain perception, only relative to one other.

We wouldn't advise changing your breathing habits in an attempt to avoid pain based on the results of this study.  

Where did the story come from?

The study was carried out by researchers from University of Jaén in Spain, and was funded by the Spanish Ministry of Science and Innovation.

It was published in the peer-reviewed journal, Pain Medicine.

Generally, the Mail Online reported the story accurately. In their article, the lead study author explained that holding your breath won't work for an unexpected injury, such as standing on a pin or stubbing a toe. But it might work if you start holding your breath before the pain kicks in – for example, anticipating the sting of an injection.

The Mail added balance by indicating other scientists were critical of the findings. They said the pain reduction was very small, and pointed out that holding your breath might make your muscles more tense, which could worsen pain in some circumstances, such as childbirth.  

What kind of research was this?

This human experimental study looked at whether holding your breath affects pain perception.

The researchers explain that holding your breath immediately after a deep inhalation slows your heart rate and increases your blood pressure. This stimulates pressure-sensing receptors called baroreceptors to send signals to the brain to reduce blood pressure.

This happens through reduced activity of the sympathetic nervous system, which is involved in the "fight or flight" response to danger. When working as it should, this feedback loop ensures blood pressure doesn't get too high.

The researchers say the dampening down of this part of the nervous system might also reduce sensitivity to pain. In this study, the researchers wanted to test their theory that increasing your blood pressure through holding your breath would reduce your perception of pain.   

What did the research involve?

Researchers used a machine to squeeze the fingernails of 38 healthy adult volunteers at different pressures to stimulate pain. Before the squeeze, the group were told to inhale slowly or to hold their breath after a deep breath in.

The researchers analysed ratings of pain in the two breathing styles to see if there was a difference. Volunteers were pre-tested to find a nail squeeze pressure they found painful and three personalised pain intensity thresholds.

Two breathing styles were tested and compared in each person. One involved breathing in slowly for at least seven seconds while the pain was applied. The other involved inhaling deeply, holding your breath while the pain was applied, before exhaling for seven seconds without actively forcing the breath out.

Both groups practised the breathing styles before the experiment began until they were confident they could do it properly. Once they had established their breathing, each volunteer had one fingernail mechanically squeezed for five seconds. After the squeeze, participants could breathe normally.

They were asked to rate the pain on a Likert scale ranging from 0 (not at all painful) to 10 (extremely painful). The experiment was repeated on the same person using three pain intensity thresholds for each breathing condition.

Volunteers knew the experiment was about pain and breathing, but they were not told which breathing experiment the study team expected to work. 

What were the basic results?

Ratings of pain intensity were consistently higher in the slow breathing group compared with the breath-holders. This held true for each of the three pain intensities tested.

Both breathing styles slowed heart rates, but this happened a little quicker, and the difference was larger, in the breath-holding condition. 

How did the researchers interpret the results?

The researchers concluded that, "During breath-holding, pain perception was lower relative to the slow inhalation condition; this effect was independent of pain pressure stimulation."

On the implications of their findings, they said: "This simple and easy-to-perform respiratory manoeuvre may be useful as a simple method to reduce pain in cases where an acute, short-duration pain is present or expected (e.g. medical interventions involving needling, bone manipulations, examination of injuries, etc.)." 

Conclusion

This small human experimental study used a fingernail-squeezing machine to cause pain to 38 willing volunteers. It found those instructed to hold their breath before the pain stimulus consistently rated their pain lower than those told to breathe slowly.

The difference between the two breathing groups was very small, although statistically significant. The biggest pain difference seen looked to be less than 0.5 points on a 10-point scale. How important this is to doctors or patients is debateable.

Similarly, the study compared two artificial breathing conditions against one another. They did not compare these against pain scores in people breathing normally throughout. This would have been useful, as it would give us an idea of whether one or both of the breathing types were any better than breathing normally.

On this point, the Mail Online reported that, "On a scale of 1 to 10, the pain experienced by volunteers fell by half a point from 5.5 to 5 when they held their breath". It wasn't completely clear whether they were talking about the difference between the two groups, or the absolute pain reduction experienced related to normal breathing.

This figure wasn't clear in the published research, so may have come from an interview. If true, it again highlights the rather small reduction in pain found.

The volunteers knew they were taking part in a pain study related to breathing. Participants' general expectations about the likely effects of the two breathing conditions therefore might have biased the results. Larger studies involving study blinding and randomisation would reduce the chance of this bias and others.

Overall, this study shows that changing your breathing pattern might affect your pain perception – but at such a small level that it might not be useful in any practical way.

There may be other dangers in holding your breath in an attempt to control pain. For example, you might feel lightheaded and pass out, or tense your muscles, which can hamper the ease of injections.

If you are worried about having an injection, you should tell the health professional before they give you an injection. They can take steps to make the experience less distressing.

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

Links To The Headlines

Hate injections? Holding your breath can make the pain of jabs more bearable. Mail Online, May 14 2015

Links To Science

Reyes del Paso G, de Guevara ML, Montoro CI. Breath-Holding During Exhalation as a Simple Manipulation to Reduce Pain Perception. Pain Medicine. Published online April 30 2015

Categories: Medical News

Single mothers have 'worse health in later life'

Medical News - Fri, 05/15/2015 - 14:30

The Daily Telegraph today tells us that: "Single mothers in England [are] more likely to suffer ill health because their families 'do not support them'."

This is a half-truth. The large international study – involving 25,000 people from England, the US and 13 other European countries – behind the headline found a link between single motherhood between the ages of 16 and 49 and worse health in later life. But it did not find this was because families do not support them.

It would appear that this claim is prompted by a trend spotted in the study by the researchers. It found that health risks were more pronounced in northern European countries and the US. While in southern European countries the risk was less pronounced.

The researchers speculated that in southern European countries there is more of a tradition of informal support services, where grandparents, aunts, uncles, cousins etc all pitch in with childcare duties. Or as the proverb puts it "It takes a village to raise a child".

While this hypothesis is plausible it is also unproven and was not backed up with any new robust data on social support as part of the study.

The study was very large and diverse so the mother health link appears real. However, the reasons and causes behind it are still to be worked out.

 

Where did the story come from?

The study was carried out by researchers from US, Chinese, UK and German universities and was funded by the US National Institute on Aging.

The study was published in the peer-reviewed Journal of Epidemiology & Community Health.

The media reporting was generally partially accurate, as most took the finding about social support at face value. The link between single motherhood and later ill health was supported by the body of this study, but the study did not collect any information on social support, so this explanation, although plausible, was not based on direct evidence. 

 

What kind of research was this?

The study investigated if single motherhood before the age of 50 was linked to poorer health later in life, and whether it was worse in countries with weaker "social [support] safety nets". To do this they analysed data collected from past cohort and longitudinal studies across 15 countries.

The researchers say single motherhood is known to be linked to poorer health, but didn’t know whether this link varied between countries.

Analysing previously collected data is a practical and legitimate study method. A limitation is that the original information was collected for specific reasons that usually differ from the research aims when coming to use it later. This can mean some information that would ideally be analysed is not there. In this study, the researchers couldn’t get information on social support networks, which they thought might explain some of their results.

 

What did the research involve?

The research team analysed health and lifestyle information on single mothers under 50 collected from existing large health surveys. The single mothers' health was documented into older age and compared across 15 countries.

Data was available from 25,125 women aged over 50 who participated in the US Health and Retirement Study; the English Longitudinal Study of Ageing; or the Survey of Health, Ageing and Retirement in Europe (SHARE). Thirteen of the 21 countries represented by SHARE (Denmark, Sweden, Austria, France, Germany, Switzerland, Belgium, The Netherlands, Italy, Spain, Greece, Poland, Czech Republic) had collected relevant data. With the US and England on board, this gave 15 countries for final analysis.

The researchers used data on number of children, marital status and any limitations on women's capacity for routine daily activities (ADL), such as personal hygiene and getting dressed, and instrumental daily activities (IADL), such as driving and shopping. Women also rated their own health.

Single motherhood was classified as having a child under the age of 18 and not being married, rather than living with a partner.

 

What were the basic results?

Single motherhood between the ages of 16 and 49 was linked to poorer health and disability in later life in several different countries. The risks were highest for single mothers in England, the US, Denmark and Sweden.

Overall 22% of English mothers had experienced single motherhood before age 50, compared with 33% in the US, 38% in Scandinavia, 22% in western Europe and 10% in southern Europe.

While single mothers had a higher risk of poorer health and disability in later life than married mothers, associations varied between countries.

For example, risk ratios for ADL limitations were significant in England, Scandinavia and the US but not in western Europe, southern Europe and eastern Europe.

Women who were single mothers before age 20, for more than eight years, or resulting from divorce or non-marital childbearing, had a higher risk.

 

How did the researchers interpret the results?

The researchers' concluded that: "Single motherhood during early adulthood or mid-adulthood is associated with poorer health in later life. Risks were greatest in England, the US and Scandinavia."

Although they didn’t have good data to back it up, they suggested that social support and networks may partially explain the findings. For example, areas like southern Europe, which the researchers say have strong cultural emphasis on family bonds, were not associated with higher health risks.

They add: "Our results identify several vulnerable populations. Women with prolonged spells of single motherhood; those whose single motherhood resulted from divorce; women who became single mothers at young ages; and single mothers with two or more children, were at particular risk."

 

Conclusion

This large retrospective study of over 25,000 women linked single motherhood between the ages of 16 and 49 with worse health in later life. This is not a new finding. What was new was that the link varied across different countries. Risks were estimated as greatest in England, the US and Scandinavia for example, but were less consistent in other areas of Europe.

The research team thought this might be caused by differences in how social networks supported single mothers in different countries, such as  being able to rely on extended families. But they had no data to directly support this. They did not have information on, for example, socioeconomic status, social support or networks during single motherhood, so could not analyse whether these were important causes. They also did not know whether any of the women they classed as single were actually in non-marital or same-sex partnerships, which may have affected results.

Health status in later life is likely to be linked to a complex number of interrelated factors. Being a single mum may be one, social networks might be another. But based on this study we don't yet know for sure, or the mechanisms by which this could lead to worse health.

Studies that collect information on levels of social support alongside health outcomes for single women would be able to tell us whether this is the likely cause, but getting this data may not be easy.

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

Links To The Headlines

Single mothers more likely to suffer ill health, study finds. The Independent, May 14 2015

'Health risk' for single mothers. Mail Online, May 15 2015

Single mothers in England more likely to suffer ill health because their families 'do not support them'. The Daily Telegraph, May 14 2015

Links To Science

Berkman LF, Zheng Y, Glymour MM, et al. Mothering alone: cross-national comparisons of later-life disability and health among women who were single mothers. Journal of Epidemiology and Community Health. Published online May 14 2015

Categories: Medical News