Heart health benefits of light drinking brought into question

July 10, 2014, London School of Hygiene & Tropical Medicine

A reduction in alcohol consumption, even for light-to-moderate drinkers, could be linked to improved cardiovascular health, including a reduced risk of coronary heart disease, lower body mass index and blood pressure, according to new research published in The BMJ.

These latest findings challenge the results of previous observational studies which found that the consumption of light-to-moderate amounts of alcohol (12-25 units per week) may have a protective effect on cardiovascular health.

The research, led by the London School of Hygiene & Tropical Medicine with University College London and University of Pennsylvania, looked at evidence from over 50 studies into the drinking habits and cardiovascular health of over 260,000 people. They found that individuals who carry a genetic variant which tends to lower their alcohol consumption have, on average, a more favourable cardiovascular profile. The authors say this suggests that a reduction in alcohol consumption, even for light-to-moderate drinkers, is beneficial for cardiovascular health.

Specifically, the researchers found that these individuals had on average a 10% lower risk of having , lower and a lower Body Mass Index (BMI).

Senior author Juan P. Casas, Professor of Epidemiology at the London School of Hygiene & Tropical Medicine, said: "While the damaging effects of heavy alcohol consumption on the heart are well-established, for the last few decades we've often heard reports of the potential health benefits of light-to-moderate drinking. However, we now have evidence that some of these studies suffer from limitations that may affect the validity of their findings. In our study, we saw a link between a reduced consumption of alcohol and improved cardiovascular health, regardless of whether the individual was a light, moderate or heavy drinker. Assuming the association is causal, it appears that even if you're a light drinker, reducing your alcohol consumption could be beneficial for your heart."

In this study, the researchers used a gene that serves as an indicator of alcohol consumption. Individuals that carry a genetic variant of the 'alcohol dehydrogenase 1B' gene are known to breakdown alcohol at a different pace. This causes unpleasant symptoms including nausea and facial flushing, and has been found to lead to lower levels of alcohol consumption in the long term. By using this genetic variant as an indicator of lower alcohol consumption, they were able to find associations between these individuals and improved cardiovascular health.

Studies into the long-term of alcohol can be challenging, due to the difficulty of setting up randomised control trials involving many individuals who will maintain the same alcohol consumption levels over an extended period of time. The authors say that their study's genetic approach parallels the principles of a randomised control trial and therefore makes it less prone to some of the limitations of previous observational studies. These limitations are partly due to bias from the effects of other good health behaviours associated with a lifestyle of low-to-moderate alcohol consumption. This may explain why a has been observed in past studies, but does not mean that alcohol itself is protective.

Previous observational studies are also limited by the issue of distinguishing between self-reported non-drinkers, who may include those who have never consumed alcohol, and those who consumed alcohol in the past but have since stopped as a result of ill-health. Issues like these make it difficult for observational studies to assess the health effects of long-term alcohol consumption levels.

The current study's results strongly suggest that reduction of alcohol consumption is beneficial for , and is closer to establishing causality than observational studies, however further replication of similar genetic studies using large-scale prospective studies, such as the UK Biobank, will be needed.

The study was funded by the British Heart Foundation and the Medical Research Council.

Dr Shannon Amoils, Senior Research Advisor at the British Heart Foundation, said: "Studies into alcohol consumption are fraught with difficulty in part because they rely on people giving accurate accounts of their drinking habits. Here the researchers used a clever study design to get round this problem by including people who had a gene that predisposes them to drink less. The results reinforce the view that small to moderate amounts of alcohol may not be healthy for the heart although the study would need to be repeated in a larger group of people for definitive results. Whilst the heart health effects of light to moderate are still unclear, what is clear is that drinking more than the recommended limits of alcohol can have a harmful effect on the heart."

Explore further: Drinking alcohol several times a week increases the risk of stroke mortality

More information: Michael V Holmes, Caroline E Dale et al. Association between alcohol and cardiovascular disease: mendelian randomisation analysis based on individual participant data. The BMJ. DOI: 10.1136/bmj.g4164

Related Stories

Drinking alcohol several times a week increases the risk of stroke mortality

March 19, 2014
Consuming alcohol more frequently than twice a week increases the risk of stroke mortality in men, according to a study carried out at the University of Eastern Finland. The results show that the effects of alcohol are not ...

Moderate alcohol intake is associated with a lower risk of kidney cancer

July 19, 2012
A majority of previous epidemiologic studies have shown that moderate drinking is associated with a lower risk of kidney cancer, which may affect about 1% of the general population. In published prospective cohort studies, ...

A wine a day associated with lower risk of depression

August 30, 2013
Drinking wine in moderation may be associated with a lower risk of developing depression, according to research published in Biomed Central's open access journal BMC Medicine. The reported findings by the PREDIMED research ...

Hazardous drinking in UK athletes linked with alcohol industry sponsorship

July 2, 2014
New research from the University of Manchester (UK) and Monash University (Australia) shows a link between alcohol sponsorship and hazardous drinking in UK athletes.

Frequency of alcohol consumption and cardiovascular risk factors

November 20, 2012
Critique 096: Frequency of alcohol consumption and cardiovascular risk factors: implications for drinking guidelines 20 November 2012

Does binge drinking affect rugby performance?

June 13, 2014
A Massey University study has found a big night on the booze has little effect on the anaerobic performance of rugby players the following day.

Recommended for you

Women run faster after taking newly developed supplement, study finds

January 19, 2018
A new study found that women who took a specially prepared blend of minerals and nutrients for a month saw their 3-mile run times drop by almost a minute.

Americans are getting more sleep

January 19, 2018
Although more than one in three Americans still don't get enough sleep, a new analysis shows first signs of success in the fight for more shut eye. According to data from 181,335 respondents aged 15 and older who participated ...

Wine is good for you—to a point

January 18, 2018
The Mediterranean diet has become synonymous with healthy eating, but there's one thing in it that stands out: It's cool to drink wine.

Sleep better, lose weight?

January 17, 2018
(HealthDay)—Sleeplessness could cost you when it's time to stand on your bathroom scale, a new British study suggests.

Who uses phone apps to track sleep habits? Mostly the healthy and wealthy in US

January 16, 2018
The profile of most Americans who use popular mobile phone apps that track sleep habits is that they are relatively affluent, claim to eat well, and say they are in good health, even if some of them tend to smoke.

Improvements in mortality rates are slowed by rise in obesity in the United States

January 15, 2018
With countless medical advances and efforts to curb smoking, one might expect that life expectancy in the United States would improve. Yet according to recent studies, there's been a reduction in the rate of improvement in ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.