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Can exercise offset some of the harms of regular drinking?

Fri, 09/08/2017 - 17:28

"Adults who booze regularly but exercise for five hours a week are no more likely to die than teetotallers," the Mail Online reports.

A study suggests exercise may compensate for some, but certainly not all, of the harms associated with excessive alcohol consumption. This latest study looked at deaths from cancer and cardiovascular disease, as well as premature death in general (usually judged to be dying before the age of 75).

Researchers looked at around 10 years' worth of national survey data from UK adults aged over 40. Unsurprisingly, they found links between all-cause and cancer mortality in inactive people. But they also found increasing levels of physical activity generally removed the association with drinking habits. In fact, occasional drinking was associated with a significant reduction in all-cause mortality for the most active of people.

Although the study had strengths in its large sample size and regular follow-up, we can't be sure that any links observed were solely down to the interaction between alcohol and exercise. For example, people who are physically active may also avoid smoking and consume healthy diets. It is difficult to completely control for such influences when analysing data like this.

While regular exercise may mitigate against some of the harms associated with excessive alcohol consumption it certainly won't make you immune. Many world-class sportspeople, such as George Best and Paul Gascoigne, have had both their careers and lives blighted by drinking.


Where did the story come from?

The UK-based study was carried out by an international collaboration of researchers from Canada, Australia, Norway and the UK. The health surveys on which the study was based were commissioned by the Department of Health, UK. Individual study authors also reported receiving funding from the National Health and Medical Research Council and University of Sydney. 

The study was published in the peer-reviewed British Journal of Sports Medicine. 

The media coverage around this topic was generally overly optimistic, highlighting that by exercising, individuals can completely undo the harm caused by excessive alcohol consumption, which is untrue.

In particular, the Mail Online claimed "Adults who booze regularly but exercise for five hours a week are no more likely to die than teetotallers" which could send out the wrong message to the public.


What kind of research was this?

This cohort study analysed data from British population-based surveys: Health Survey for England (HSE) and the Scottish Health Survey (SHS) to investigate whether physical activity is able to moderate the risk between alcohol consumption and mortality from cancer and cardiovascular diseases.

Cohort studies like this are useful for assessing suspected links between an exposure and outcome. However, there are potentially other factors that have a role to play in such associations and therefore the study design doesn't allow for confirmation of cause and effect.


What did the research involve?

The researchers collected data on 36,370 men and women aged 40 or above from Health Survey for England (1994; 1998; 1999; 2003; 2004; and 2006) and the Scottish Health Survey (1998 and 2003). Among other things, the participants were asked about their current alcohol consumption and physical activity.

Alcohol intake was defined by six categories (UK units/week):

  • never drink (lifetime abstainers)
  • ex-drinkers
  • occasional drinkers (haven't drank anything in past seven days)
  • within (previous) guidelines: <14 units (women) and <21 units (men)
  • hazardous: 14-15 units (women) and 21-19 units (men)
  • harmful: >35 (women) and >49 (men)

Frequency and type of physical activity in the past four weeks was questioned and converted into metabolic equivalent task-hour (MET-hours, which are an estimate of metabolic activity) per week according to national recommendations:

  • inactive (≤7 MET-hours)
  • lower level of active (>7.5 MET-hours)
  • higher level of active (>15 MET-hours)

The surveys were linked to the NHS Central Register for mortality data and the participants were followed up until 2009 (HSE) and 2011 (SHS). There were 5,735 recorded deaths; deaths from cancer and cardiovascular disease were of most interest for this study.

The data was analysed for associations between alcohol consumption and the risk of death from all-causes, cancer and cardiovascular disease. The results were then analysed according to levels of physical activity.

Potential confounders (such as sex, body mass index and smoking status) were controlled for.


What were the basic results?

Overall, the study found a direct link between all levels of alcohol consumption and risk of cancer mortality. It also found that increasing levels of physical activity reduced this association with cancer mortality, and also reduced the link with death from any cause.

  • In individuals who reported inactive levels of physical activity (≤7 MET-hours), there was a direct association between alcohol consumption and all-cause mortality.
  • However, in individuals who met the highest level of physical activity recommendations a protective effect of occasional drinking on all-cause mortality was observed (hazard ratio: 0.68; 95% confidence interval (CI): 0.46 to 0.99). It should be noted that this result just skimmed the cut-off point for statistical significance.
  • In this high activity group, there was no link between all-cause mortality and alcohol consumption within guidelines, or even hazardous amounts, but the risk was still increased for those drinking harmful amounts.
  • The risk of death from cancer increased with the amount of alcohol consumed in inactive participants, ranging from a 47% increased risk for those drinking within guidelines to 87% increased risk for those with harmful drinking.
  • In people with higher activity levels (above 7.5 MET hours) there was no significant link between any amount of alcohol consumption and cancer mortality.
  • No association was found between alcohol consumption and mortality from cardiovascular disease, although a protective effect was observed in individuals who reported the lower and higher levels of physical activity (>7.5 MET-hours) and (>15 MET-hours) respectively.


How did the researchers interpret the results?

The researchers concluded "we found evidence of a dose–response association between alcohol intake and cancer mortality in inactive participants but not in physically active participants. [Physical activity] slightly attenuates the risk of all-cause mortality up to a hazardous level of drinking."



This study aimed to explore whether physical activity is able to moderate the risk between alcohol consumption and mortality from cancer and cardiovascular diseases. It found that increasing levels of physical activity reduced the association for death from both all-causes and cancer.

This study has strengths in its large sample size, comprehensive assessments and long duration of follow-up. The findings are interesting, but there a few points to bear in mind:

  • As the authors mention, cohort studies such as this are unable to confirm cause and effect. Though the researchers have tried to account for various potential health and lifestyle confounding variables, there is the possibility that others are still influencing the results. A notable one is dietary habits which weren't assessed. Also, for example, the former drinkers may have quit due to other health issues which may have introduced bias.
  • The study was unable to look at binge drinking levels of alcohol consumption which would have likely had important health implications.
  • Additionally, there is always the possibility with self-reported surveys that the participants either under or over-reported their drinking habits which can increase the chance of misclassification bias.
  • Though having a large sample size, fewer people reported harmful drinking levels, so links within this category may be less reliable.
  • The study has only looked at the link between alcohol and actually dying from cancer or cardiovascular disease. Links may be different if they looked at associations between alcohol and just being diagnosed with cancer or heart disease, for example.
  • The study is also only representative of adults over the age of 40.

Overall, maintaining a healthy lifestyle seems to be the best bet for reducing the risk of any chronic disease, be it through physical activity, balanced diet or reasonable alcohol consumption.

Current alcohol recommendations for both men and women are to drink no more than 14 units per week.  

Links To The Headlines

How exercise undoes the harm from drinking: Adults who booze regularly but exercise for five hours a week are no more likely to die than teetotallers. Mail Online, September 8 2016

Two hours a week of exercise could offset the dangers of alcohol. The Daily Telegraph, September 8 2016

Exercise can cut risk from alcohol-related diseases, study suggests. The Guardian, September 8 2016

Links To Science

Perreault K, Bauman A, Johnson N, et al. Does physical activity moderate the association between alcohol drinking and all-cause, cancer and cardiovascular diseases mortality? A pooled analysis of eight British population cohorts. British Journal of Sports Medicine. Published online August 31 2016

Sex link to older people's brain power, says study

Thu, 06/22/2017 - 19:30

"Sex is the key to staying sharp in old age," reports the Mail Online after researchers found older people who have regular sex scored better on two of five brain tests.

Participants who had sex at least once a week scored higher on tests that measured their verbal fluency and spatial awareness compared with those who had no sex at all.

The verbal fluency test involved asking participants to say as many words beginning with a letter – in this case "f" – in a minute, and also name as many animals as they can.

In the spatial awareness test, participants had to draw an image, such as a square, triangle, cube or pyramid, and draw a clock face from memory.

These tests are part of the Addenbrookes Cognitive Examination III (ACE-III) test, a standard test to measure brain function.

The study involved 73 people aged between 50 and 83, and was conducted by researchers at the universities of Coventry and Oxford.

Researchers say their results "demonstrate that older men and women who engage in regular sexual activity have better cognitive functioning than those who do not … or do so infrequently".

But it's not clear why.

Previous studies have shown that older people who have active social lives and keep physically active are likely to have better cognitive function.

It's possible the social or physical elements of sexual activity are simply another aspect of this previous finding.

Researchers speculated it could also be caused by the release of dopamine, a chemical that transmits information in the brain during activities like sex.

We can't draw any conclusions from this study about whether sex keeps the brain functioning well, or whether people with better cognitive function are more likely to continue to have sex – or if the link is caused by something else entirely.  

Where did the story come from?

The study was carried out by researchers from Coventry University and the University of Oxford.

It was funded by the Coventry University Pump-Prime Research Grant Scheme. 

The study was published in the peer-reviewed Journals of Gerontology and is free to read online.

The Mail Online's story was mostly accurate, although the reporting assumed that increased sexual activity was the cause of better cognitive function, which may not be the case.

Most of the media coverage made the same error. The i newspaper stated that, "Having more sex can boost brain power", while The Sun incorrectly informed readers that, "Testers aged up to 83 were asked to keep a bonking diary".

What kind of research was this?

This was a cross-sectional observational study. This type of study can show an association between different things, but can't tell whether one thing (in this case sexual activity) causes the other (cognitive function), or whether other factors are at play.

What did the research involve?

Researchers recruited 73 volunteers over the age of 50: 45 women and 28 men.

They were asked to say how often they'd had sex over the past year:

  • never
  • once a month
  • once a week

They then filled out a general health questionnaire and took a range of tests designed to assess their mental abilities.

Researchers then looked at whether people who said they'd had sex never or monthly did better or worse on the tests than people who said they'd had sex weekly.

The researchers used the Addenbrookes Cognitive Examination III (ACE-III) test, which includes brief measures to assess people's abilities in attention, memory, fluency, language, and visual-spatial fields (how well people can visualise things in relation to those around them).

They adjusted their figures to account for people's age, years in education, gender, and cardiovascular health, as these factors might affect both how often they had sex and their cognitive abilities.

What were the basic results?

Frequency of sexual activity didn't vary significantly by age, education level, cardiovascular health, or other factors measured.

People who said they'd not had sex in the past year had on average lower scores for overall cognitive function and fluency compared with those who said they'd had sex weekly.

People who reported having sex monthly had on average lower scores for fluency and spatial awareness, although the difference here was small and may just have been down to chance.

More people in the group of 73 said they'd had sex weekly than monthly or never. All 10 of the respondents who said they never had sex were women.

More women than men said they'd had sex monthly (65% women and 35% men), and about equal numbers of men and women said they'd had sex weekly.

How did the researchers interpret the results?

The researchers say their results "demonstrate that older men and women who engage in regular sexual activity have better cognitive functioning than those who do not … or do so infrequently".

They suggest this might be because of the biological effect of dopamine, a chemical that transmits information in the brain, and is linked to pleasure and reward pathways.

They say that, "We can only speculate that continued engagement in regular sexual activity may have a positive influence on cognitive function", but add "the findings have important implications for the maintenance of intimate relationships in later life".


This study got widespread and enthusiastic coverage in the media, as many studies about sex do. But the findings are limited and it's difficult to draw conclusions from them.

As the researchers point out, we already know that a healthy social life and staying physically active seem to help keep people's cognitive abilities sharper as they age.

It's not a surprise that sexual activity, which has elements of both social and physical activity, is also linked to better cognitive function.

But this small observational study only provides a snapshot in time of how sexual activity may link to brain function.

We can't draw any firm conclusions about whether sexual activity keeps the brain functioning well, or whether people with better cognitive function are more likely to continue to have sex.

The results of the study are quite limited. Although overall scores of cognitive function were better for people who reported having sex weekly, this seems to have been driven by only two of the five types of mental ability, and the relationships weren't consistent.

And it's hard to explain how having sex monthly could give you worse spatial awareness than either having sex weekly or not at all, for example.

While continued sexual activity may be pleasurable and generally healthy into older age, this study doesn't mean it's a panacea for keeping the brain sharp.

If you're older and don't want to engage in sexual activity, the results of this study don't mean there's any reason to worry about it.

Links To The Headlines

Sex is the key to staying sharp in old age! Regularly getting intimate improves vocabulary and visual awareness. Mail Online, June 22 2017

Over 50s 'should have more sex to boost their IQ'. iNews, June 22 2017

Hump away brain decay: Over-50s who have more sex have better memory and visual awareness, says study. The Sun, June 22 2017

Frequent sex is officially good for your health and it can boost your brain performance. Daily Express, June 22 2017


Links To Science

Wright H, Jenks RA, Demeyere N. Frequent Sexual Activity Predicts Specific Cognitive Abilities in Older Adults. Journals of Gerontology: Psychological Sciences. Published online June 21 2017

'Contaminated air' on planes linked to health problems

Wed, 06/21/2017 - 01:00

"Toxic fumes in aircraft cabins could cause serious health problems, scientists warn," reports The Sun. This is based on a UK study investigating air contamination on aircraft and its possible effects on the health of pilots and cabin crew.

The researchers say the air supply on planes can become contaminated by leaks of oil or other chemicals from the engines and they wanted to find out if this was associated with any health problems.

The study, published in the World Health Organization journal, found there is a link between exposure to contaminated air and short-term problems such as drowsiness, loss of consciousness, headache and tremors, and longer-term issues such as problems with memory or concentration and fatigue.

This is mainly worrying for pilots and staff on aircrafts, but could also be a concern for passengers if exposure to highly contaminated air causes a pilot to feel drowsy or pass out. However, only a few case studies of serious air contamination were investigated in this study, suggesting these events are rare.

The study didn't look in detail at whether exposure to contaminated air on planes was harmful to passengers, so it's not possible to draw firm conclusions about whether there's a health risk for people who fly regularly or only occasionally.

Where did the story come from?

The study was carried out by researchers from the University of Stirling and the University of Ulster in the UK, as well as a consultant respiratory physician from Melbourne in Australia. It received no sources of funding.

The study was published in the peer-reviewed journal Public Health Panorama, a journal of the World Health Organization. It is open access, meaning you can read it online for free (PDF, 314kb).

The UK media generally reported the story accurately, although the Sun's message of "Flying should 'come with a health warning' as toxic fumes contaminate air in cabins leading to serious health problems, research suggests" is fairly misleading as it suggests the research was done on passengers, when it was actually only carried out on aircraft staff.

What kind of research was this?

This was a combination of two studies, one involving a survey of pilots from the UK and the second an analysis of 15 case reports of potential cabin air quality incidents. They both aimed to look at the circumstances and symptoms of aircrew working in the pressurised air environment of aircraft. 

There have been concerns over the years regarding the health effects of exposure to aircraft contaminated air for aircrew. Unfiltered breathing air is provided to the cabin by the engine compressor. If oil leaks over the engine oil seals, chemicals can enter the air being supplied to the cabin. This might mean those on board may be exposed to some potentially harmful substances.

By combining these two types of studies, the authors aimed to carry out a more in-depth investigation of aircrew involved in suspected aircraft contaminated events by seeing if the reported symptoms were consistent with exposure to pyrolysed (heated) jet engine oil and other chemicals.

What did the research involve?

Researchers carried out two independent studies to investigate the circumstances and symptoms of aircrew who worked in the pressurised air environment of aircraft.

The first was a survey of UK British Airways pilots between 2005 and 2009 who agreed to a telephone interview or responded to a written questionnaire.

The pilots were asked:

  • whether they were aware of exposure to contaminated air
  • how they thought the contaminated air affected them
  • about any medical diagnoses they had

Of all the pilots who were contacted, 274 (14%) agreed to participate.

The second study involved 15 case reports from Australia, the US, Germany and the UK, of potential cabin air quality incidents. These particular cases were chosen because the health problems reported were suggestive of exposure to contaminated air.

Data sources included: the airlines, crew and maintenance reports, incident investigation and regulator reports, health effects and medical records, as well as media, union and legal reports.

Symptoms for both studies were recorded. 

The substances found in the engine oils and other chemicals were then measured against European standards to see if they were at hazardous levels or not.

What were the basic results?

From the survey:

  • Of the 274 pilots surveyed, 88% reported exposure to aircraft contaminated air, mostly in the form of fumes, and 34% reported frequent exposure.
  • 142 pilots reported specific symptoms and diagnoses, 30 reported health problems but gave no specific details, 77 reported no health effects and 25 failed to respond either way.
  • Acute adverse effects most commonly reported were: breathing problems, exhaustion or fatigue, dizziness and reduction in performance level.
  • Long-term effects most commonly reported were: breathing problems, poorer levels of performance, memory impairment and chronic fatigue.

Among the case studies:

  • In 33% of the incidents both pilots ability to fly the plane was affected during the air contamination.
  • 53% of events included long-term adverse effects for one or more crew members.
  • Chronic health problems diagnosed at some point after the exposure event included asthma, post-traumatic stress disorder (PTSD), problems with memory or concentration, seizures (fits) and cancer.
  • Nine pilots either became unfit to fly or died.
  • 80% of incidents occurred during take off or landing and 87% were linked to positive maintenance findings of oil leakage.
How did the researchers interpret the results?

The authors concluded that "aircraft air supplies contaminated by pyrolysed [heated] engine oil and other aircraft fluids can reasonably be linked to acute and chronic symptoms, findings and diagnoses, thus establishing causation".

They further add that "there is an obvious need for a clearly defined internationally recognised medical protocol, occupational syndrome and disease recognition, and health and environmental data collection".


These findings indicate that on rare occasions, pilots have not been able to perform as usual due to poor air quality in the cabin. Also poor air quality has been linked to health problems in the long term.

However, there are some limitations of the study that need to be considered:

  • The authors claim they have demonstrated a cause-and-effect relationship based on certain criteria. But with the exception of the acute air toxicity incident investigation reports in the second study, these types of study cannot prove causality. While it is likely that exposure to chemicals is toxic, this study did not link many of the symptoms with on-board air samples. There is still a possibility that the acute symptoms experienced by the pilots and crew were brought on by other things too, not just the contaminated air. With regard to the potential chronic effects, it is even harder to eliminate other factors that may have played a role.
  • The data in the pilot survey was self-reported, which might be subject to bias as people might not remember accurately or might exaggerate health outcomes. There was also a high risk of selection bias as only a small proportion of pilots invited to participate agreed. It is likely that those who didn’t participate hadn’t experienced any obvious health problems.
  • The data from the case studies comes from multiple sources that might not have consistent ways of reporting things, so analysing them as a group might lead to inaccuracies.
  • We do not know if frequency of exposure affects the health outcomes (if the symptoms get worse the more times staff are exposed to contaminated air). This might have some consequence for frequent flyers, so it’s important to know.

Links To The Headlines

Contaminated air on flights can lead to long-term sickness and airlines are ignoring the problem, study claims. The Independent, June 19 2017

Toxic fumes in aircraft cabins could cause serious health problems, scientists warn. The Sun, June 19 2017

Contaminated air on planes linked to crew ill-health, study finds. The Guardian, June 19 2017

Air in a plane cabin can damage your health, say scientists. Mail Online, June 19 2017

Flight safety 'degraded' by contaminated air. BBC, June 19 2017

Links To Science

Michaelis S, Burdon J, Vyvyan Howard C. Aerotoxic syndrome: a new occupational disease? (PDF, 314kb). Public Health Panorama. Published online June 2017

Even moderate drinking may damage the brain

Wed, 06/07/2017 - 18:30

"Even moderate drinking can damage the brain," The Guardian reports. A new study, involving brain scans and cognitive testing, suggests that moderate drinking, over many years, could damage areas of the brain linked to memory and cognitive function.

The results showed that the higher the amount of alcohol consumed a week, the higher the risk of damage to certain areas in the brain, including those involved in memory.

This association was not found for "light" drinkers (people who consume between one and seven units a week). However, the scan was only performed once so we don't know if and when the brain structures changed or whether the changes were caused by other factors.

The researchers also found that people drinking alcohol in moderate or heavy quantities (over seven units a week) had a faster decrease in ability to name words beginning with the same letter but no difference for any other brain test.

Despite anecdotal reports to the contrary, many of which were promoted by the media, no protective effect of "light" drinking on cognitive function compared to completely abstaining from alcohol was found.

UK guidelines on alcohol were changed last year to reflect evidence that there is no such thing as a "safe level" of drinking; just a level when harms were at their lowest.

The guidelines now recommend that both men and women drink no more than 14 units of alcohol per week – the equivalent of around six pints of beer, and this study seems to support these guidelines.


Where did the story come from?

The study was carried out by researchers from the University of Oxford and University College London in the UK and was funded by the UK Medical Research Council, the Gordon Edward Small's Charitable Trust and the HDH Wills 1965 charitable trust. There were no reported conflicts of interest.

The study was published in the peer-reviewed British Medical Journal on an open-access basis, meaning it is freely available to access and read online.

The UK media's reporting of the study was generally accurate, with the noticeable exception of the headline printed by The Sun, which claimed that "less than a pint a day means you're 'THREE TIMES more likely to develop early signs of Alzheimer's'". This is not an accurate reflection of the study findings as none of the participants had developed Alzheimer's disease.


What kind of research was this?

This was a prospective cohort study, following adults over 30 years to look at their weekly alcohol intake and cognitive performance over time and brain structure at the end of the study.

This type of study is best for looking at things like alcohol intake, as a randomised controlled trial where participants get allocated to a weekly alcohol intake level would be unethical. Following people over time and asking them to record their weekly intake is a much better way of studying the effects of alcohol on the brain and cognitive performance.


What did the research involve?

Researchers took 550 participants who were already enrolled in the Whitehall II study, a study that started in 1985 aiming to investigate the relationship between socioeconomic status, stress and cardiovascular health in civil servants.

Over 30 years sociodemographic, health and lifestyle variables (including alcohol use) were measured at intervals:

  • phase I: 1985-88
  • phase 3: 1991-93
  • phase 5: 1997-99
  • phase 7: 2003-04
  • phase 9: 2007-09
  • phase 11: 20011-12

Average alcohol use across the study was calculated as mean consumption a week averaged over all study phases. Participants were categorised as:

  • "abstinent" if they consumed less than one unit of alcohol a week
  • "light drinking" was defined as between one and less than seven units
  • "moderate drinking" was defined as seven to less than 14 units a week for women and seven to less than 21 units for men
  • "unsafe drinking" was defined according to pre-2016 (21 units a week for men and 14 units for women) and newly revised UK Department of Health guidelines (more than 14 units for men and women)

The researchers looked at brain structure including grey matter density, hippocampal atrophy and white matter by carrying out a magnetic resonance imagining (MRI) scan on participants at the end of the study (between 2012 and 2015).

Grey matter consists of a range of specialised nerve cells while white matter mainly consists of cells that help send signals through the brain. The hippocampus is an area of the brain involved with memory.

Cognitive function was also assessed at phases 3, 5, 7, 9 and 11 and at the time of scanning with tests including :

  • semantic fluency – naming as many words as possible in the same category, such as animals
  • lexical fluency – naming as many words beginning with same letter as possible
  • performance on the Montreal cognitive assessment – which checks for mild cognitive impairment
  • trail making test – connecting dots to look at visual search speed and mental flexibility
  • Rey-Osterrieth complex figure test – reproduce a complex line drawing
  • Hopkins verbal learning test – asking a person to remember and then recall a short list of words
  • Boston naming test – to measure word recall and naming ability
  • digit substitution test – matching symbols with their corresponding digits

Age, sex, education, smoking, social activity, blood pressure, smoking, history of cardiovascular events and cardiovascular drugs were assessed by questionnaire. Social class, lifetime history of major depressive disorder and drug use were also taken into account.


What were the basic results?

Median alcohol consumption was 11.5 units a week for men and 6.4 units for women and this did not increase significantly over the phases of the study for the group as a whole.

Brain Structure:
  • Compared with abstinence, greater alcohol consumption was associated with increased odds of hippocampal degeneration in a dose dependent way – the more alcohol, the more atrophy.
  • In light drinkers, (one to less than seven units a week) there was no difference in brain structure compared with those who abstained from alcohol.
  • Those consuming more than 30 units a week were at five times higher risk of right sided hippocampal atrophy compared with abstainers (odds ratio [OR] 5.8, 95% confidence interval [CI] 1.8 to 18.6). The total number of people this was based on was small though; 24 out of 31 heavy drinkers had signs of atrophy compared to 13 out of 37 abstainers.
  • Overall, moderate drinkers (14 to less than 21 units a week) had a three times higher risk of hippocampal atrophy compared with abstainers (OR 3.4, 95% CI 1.4 to 8.1).
  • Women who drank moderately had no significant difference with abstainers, but men who drank moderately did.
Cognitive functioning:
  • Of the 10 tests of brain function, only one result was significant; lexical fluency.
  • Higher alcohol consumption predicted a faster decline in lexical fluency. Over the 30 years, people drinking seven to less than 14 units experienced 14% greater reduction in lexical fluency, those drinking 14 to less than 21 units 17% greater reduction and those drinking more than 21 units a 16% greater reduction than those who abstained from alcohol.


How did the researchers interpret the results?

The researchers concluded: "the finding that alcohol consumption in moderate quantities is associated with multiple markers of abnormal brain structure and cognitive function has important potential public health implications for a large sector of the population."

They further add that their findings "support the recent reduction in UK safe limits and call into question the current US guidelines, which suggest that up to 24.5 units a week is safe for men, as we found increased odds of hippocampal atrophy at just 14-21 units a week, and we found no support for a protective effect of light consumption on brain structure. Alcohol might represent a modifiable risk factor for cognitive impairment, and primary prevention interventions targeted to later life could be too late."



The results in this study indicate a link between alcohol intake – even moderate intake – and structural changes in the brain and decline in the ability to list words beginning with the same letter. The majority of cognitive functioning tests showed no association with alcohol intake.

This 30 year-long study has the ability to investigate changes in cognitive ability over a long period of time but does have some limitations:

  • The participants are all people who were civil servants in the 1980s and were mostly male and more middle class and higher IQ than the general population, meaning results might not be applicable to the UK as a whole.
  • The effect of hippocampal atrophy was found in men and not women which may be down to the lower sample size of women and that few of them drank heavily.
  • The information on alcohol intake was self-reported and therefore might be inaccurately reported by participants.
  • It is difficult to link brain structure with alcohol intake when it might have been down to other confounding factors such as intelligence, cognitive stimulation and other lifestyle factors.
  • The MRI scan only took place once, at the end of the study, so it is difficult to tell if and when any changes in brain structure took place and rule out other influencing factors.

The structural changes in the brain were found to be statistically significant but it is not known if these changes are clinically significant – if they actually impact health in the long run.

As we are still unsure of the potential effect of alcohol on our brains, and the well known increased risks of cancer and liver disease, it is wise not to exceed the weekly UK limit of 14 units for both men and women.

Links To The Headlines

Even moderate drinking can damage the brain, claim researchers. The Guardian, June 6 2017

Less than a pint a day means you're 'THREE TIMES more likely to develop early signs of Alzheimer's'. The Sun, June 7 2017

Just one pint or glass of wine a night can make people 3 times more likely to see their brain shrink in size. Daily Mail, June 7 2017

Two glasses of wine a night can damage brain. The Times, June 7 2017

Links To Science

Topiwala A, Allan CL, Valkanova V, et al. Moderate alcohol consumption as risk factor for adverse brain outcomes and cognitive decline: longitudinal cohort study. BMJ. Published online June 6 2017

Cold water 'just as good as hot' for handwashing

Thu, 06/01/2017 - 18:00

"Antibacterial handwash is NO better than soap – and cold water kills as many germs as hot, experts claim," The Sun reports.

These were the main findings of a study looking at various methods of handwashing.

But the researchers only tested for E.coli bacteria, a leading cause of food poisoning. And for safety reasons, they used a strain of E.coli that isn't infectious.

The study found using colder water (15C) was just as effective at getting rid of bacteria as using hot water (38C), and antibacterial soap was not significantly more effective at removing bacteria than plain soap.

It also found washing your hands for slightly longer – 30 seconds as opposed to 15 seconds – is more effective at getting rid of the bacteria.

The researchers hope their study could be used by policymakers to inform handwashing guidelines.

But the study only compared two products, and also only looked at one organism, which doesn't cause infection in humans.

Examining the effectiveness of a wider range of products against other types of infectious organisms, such as viruses and fungi, as well as other strains of bacteria, would be required before we can safely say whether cold water is just as effective as hot.

Perhaps the most useful piece of advice to come from the study is to wash your hands for 30 seconds if you want to protect yourself against food poisoning or infections like the flu.

Where did the story come from?

The study was carried out by researchers from Rutgers University and GOJO Industries, both in the US.

No external sources of funding were reported, though it should be noted that GOJO Industries produce hand soaps and sanitiser products.

The study was published in the peer-reviewed Journal of Food Protection.

The Sun, the Daily Mail and BBC News all covered the study. Their reporting was accurate.

What kind of research was this?

This experimental study aimed to assess handwashing techniques by testing the most effective soap volume, water temperature, and lather time for getting rid of harmful bacteria.

Handwashing techniques have generated interest and been a topic of debate for a long time, with particular reference to frequency, duration, and technique.

But handwashing recommendations aren't always backed by evidence. The researchers wanted to address this gap in the data.

What did the research involve?

Researchers recruited 20 volunteers from Rutgers University to take part in this study – 10 men and 10 women with an average age of 25.

Volunteers were asked not to use any type of antimicrobial soap or hand sanitisers for the full duration of the study.

Before beginning the experiment, 1ml of a strain of E.coli that doesn't cause infection in humans was added to each volunteer's hands.

The experiment evaluated four variables as part of handwashing technique:

  • lather time (5, 10, 20 and 40 seconds)
  • soap volume (0.5, 1.0 and 2.0ml)
  • water temperature (15, 26 and 38C)
  • product formulation (plain soap versus antimicrobial soap)

One variable would be changed while the other variables remained constant to study the effect of each one. Each experiment was replicated 20 times.

Volunteers were given instructions on how much soap to use (number of pumps), when to wet their hands, when to stop lathering, and when to stop rinsing.

They were asked not to dry their hands at the end of the experiment so any remaining bacteria weren't removed.

Samples were collected from the volunteers' hands immediately after they were washed.

Comparisons were then made between each handwashing technique and the number of bacteria left on the volunteers' hands after each experiment.

What were the basic results?

Overall, there were some interesting findings:

  • Using an antimicrobial soap formulation wasn't found to be significantly more effective than the plain soap at removing bacteria during any test washes. The mean reduction in bacteria for antimicrobial soap was 1.94 log colony forming units (CFU) (range: 1.83 to 2.10) whereas for the bland soap it was 2.22 log CFU (range: 1.91 to 2.54). CFU logs are a measurement of live bacteria in a sample.
  • There was no significant reduction in bacteria after handwashing between the lowest and highest water temperatures of 15C or 38C.
  • Washing for 30 seconds (20 seconds of lathering and 10 seconds rinsing) was found to significantly reduce bacterial count compared with washing for 15 seconds (10 seconds of lathering and 5 seconds rinsing) when using plain soap. Lather time didn't affect bacterial count for antimicrobial soap.
How did the researchers interpret the results?

The researchers concluded that, "The results of this study indicate that water temperature is not a critical factor for the removal of transient micro-organisms from hands.

"Overall, the length of lather time and volume of soap used did not make a large difference, but a minimum of 0.5ml of soap and 10s of lather time is recommended based on our findings.

"Understanding which behaviours, human factors, and physiological differences influence handwashing the most may allow future studies to focus on which techniques can optimise the effectiveness of handwashing and thereby reduce infection transmission risk and improve food safety." 


This experimental study aimed to assess handwashing techniques by testing the most effective soap volume, water temperature, and lather time for getting rid of bacteria.

Contrary to current guidelines, which recommend using hot water when we wash our hands, this study found using colder water (15C) was just as effective at getting rid of bacteria.

It also found washing your hands for longer – 30 seconds – was found to be more effective than washing for 15 seconds.

The researchers hope their study will help policymakers such as the US Food and Drug Administration (FDA) to make evidence-based recommendations around handwashing techniques.

But this was a very small study with a sample size of just 20 participants. It only compared two products: a plain soap with no specific antimicrobial ingredients and an antimicrobial soap that included 1% chloroxylenol.

A more comprehensive assessment is needed, studying many more products and organisms, before we can consider changing handwashing recommendations. 

Current guidelines recommend that we wash our hands with water and soap for at least 20 seconds:

  • after using the toilet
  • after handling raw foods like chicken, meat, and vegetables
  • before eating or handling ready to eat food
  • after having contact with animals, including pets

Read more advice about handwashing.

Links To The Headlines

Antibacterial handwash is NO better than soap – and cold water kills as many germs as hot, experts claim. The Sun, May 31 2017

Washing your hands with cool water is just as effective in killing germs as using hot water – and antibacterial soap is no better than a normal cleanser, reveals study. Daily Mail, May 31 2017

Washing hands in cold water 'as good as hot'. BBC News, June 1 2017

Links To Science

Jensen DA, Macinga DR, Shumaker DJ, et al. Quantifying the Effects of Water Temperature, Soap Volume, Lather Time, and Antimicrobial Soap as Variables in the Removal of Escherichia coli ATCC 11229 from Hands. Journal of Food Protection. Published online May 15 2017

Parents' phone addiction may lead to child behavioural problems

Wed, 05/31/2017 - 17:30

"Is our smartphone addiction damaging our children?," The Guardian asks, after publication of a recent study into "technoference" – when people switch their attention away from others to check their phone or tablet.

The study, carried out in the US, involved more than 300 parents who reported on their use of digital technology, to see if they felt it affected interactions with their children and actual child behaviours. A range of technology devices were studied, including computers, television and tablets – not just smartphones.

It found half of parents reported that their use of technology disrupted interactions with their child three or more times a day. Behavioural problems in children were linked to these disruptions, but only for mother-child relationships, not for fathers.

The authors suggest this could be because in the sample, children spent more time with their mothers, so the number of "technoferences" were greater, but the true reason is unknown.

Most of us have experienced frustration or annoyance when somebody we are talking to suddenly breaks off to check their phone, so it is plausible that children go through similar emotions.

Children's behaviour can be affected by a variety of things, including life changes, the need for attention or parental mood. There is no one correct way to handle difficult behaviour but you could try talking to your child, being positive about the good things or rewarding good behaviour.

Read more advice about dealing with difficult behaviour in children.


Where did the story come from?

The study was carried out by researchers from Illinois State University and the University of Michigan Medical School, both in the US. The study was funded by The Pennsylvania State University, the National Institute on Drug Abuse and the National Institute of Child Health and Human Development.

The study was published in the peer-reviewed journal Child Development on an open-access basis, meaning it is freely available to read online.

The Guardian accurately reported the study.


What kind of research was this?

This was a cross-sectional survey aiming to look at links between "problematic parental digital technology use" (such as having trouble resisting the urge to check a device or using a device too much), "technoference" in parent-child interactions and the child's behaviour.

This type of study is good for looking at information at one point in time, however it cannot demonstrate how outcomes change over time – a prospective cohort would be needed to examine this.

Technoference has been defined as everyday interruptions in interpersonal interactions or time spent together because of digital and mobile technology devices.


What did the research involve?

The study involved heterosexual parents with a child under the age of five (mean age was three years) who were currently living with their partner or spouse. They were asked to complete a survey between 2014 and 2016.

The survey was completed by 168 mothers and 165 fathers from 170 families in US regions, of which 61% of families had more than one child. 92% of parents were white, 95% were married and 73% parents had at least a bachelor's degree.

The survey looked at the following issues:

"Problematic parental digital technology use", which was measured by a three-item self-report scale, rated from strongly agree to strongly disagree:

  • "When my mobile phone alerts me to indicate new messages, I cannot resist checking them"
  • "I often think about calls or messages I might receive on my mobile phone"
  • "I feel like I use my mobile phone too much"

Technoference in parent-child relationships, measured by mother and father self-reporting. Parents were asked "on a typical day, about how many times do the following devices interrupt a conversation or activity you are engaged in with your child?" from none to more than 20 times:

  • cellphone/smartphone
  • television
  • computer
  • tablet
  • iPod
  • video game console

Child externalising and internalising behaviour problems: parents completed parts of a Child Behavioural Checklist concerning their child's behaviour now or within the past two months:

  • externalising included items such as "can't sit still, restless or hyperactive", "easily frustrated" and "temper tantrums or hot temper"
  • internalising included items such as "whining", "sulks a lot" and "feelings are easily hurt"

Co-parenting quality – how well parents work together in child rearing – was controlled for, as well as parent depressive symptoms and parenting stress. Parents also reported various demographic information and child media use.


What were the basic results?
  • On average, mothers and fathers reported about two devices as interfering in their interactions with their child at least once or more on a typical day.
  • Parents reporting problematic use of digital technology (40% of mothers and 32% of fathers) was correlated with technoference with their child.
  • Perceived technoference in mother-child interactions was linked to child behavioural problems – both externalising and internalising behaviour – as rated by mothers and fathers.
  • However, perceived technoference in father-child interactions was not linked to behavioural issues.
  • Only 11% of parents reported that technoference did not occur and 48% reported three or more times on a typical day.
  • Demographics, depression and child age and media use did not alter the results.


How did the researchers interpret the results?

The researchers concluded that their study "is the first to show significant associations between parent self-perceptions of problematic digital technology use, perceived technoference in parenting, and reported child behavioural difficulties."



The findings of this study suggest that when mothers and fathers report being distracted by digital technology, this causes interruptions in interactions with their children. These interruptions in mothers – but not fathers – seem to have an impact on child behaviour.

The authors suggest that the poor behavioural outcomes might only be found for mother-child interactions because children might react differently to maternal versus paternal responsiveness. It could also be that children simply spend more time with their mothers on a daily basis in this sample so there were more opportunities for technoference.

However, there are some important things to consider about this research:

  • The participants were almost all white, had a high level of education and were from the US. Therefore the findings might not be relevant to other populations.
  • The survey involved self-reporting, which may be subject to bias. For example, parents may under- or over-estimate their use of digital technology or might be unwilling to honestly answer questions about their child's behaviour if they fear it would cast them in a bad light.
  • As it was cross-sectional, it only provides a snapshot of parenting and child behaviours, which might change over time.
  • Only children under the age of five were included. Technoference might have different effects on behavioural outcomes in older children – for example, it might encourage use of technology in a positive way. Further research would be needed to determine if outcomes are positive or negative.

Children can "act up" when they are tired, hungry, overexcited, frustrated or bored. Putting down your phone or tablet and engaging with your child could be an effective method of nipping such behaviour in the bud.

Read more advice about keeping children active.

Links To The Headlines

Is our smartphone addiction damaging our children? The Guardian, May 31 2017

Links To Science

McDaniel BT, Radesky JS. Technoference: Parent Distraction With Technology and Associations With Child Behavior Problems. Child Development. Published online May 10 2017