Alcohol has no heart health benefits

Posted on Fri, 25 Jul 14

The idea that alcohol is good for your heart is a popular one with drinkers. Scientifically, however, the benefits have not always been clear and a remarkable new gene interaction study suggests there is no benefit at all.  

Alcohol is a leading cause of premature death, yet paradoxically observational studies have suggested light drinkers have a reduction in cardiovascular disease. But this association has long been controversial as it could simply be related to other social and lifestyle factors typical of light drinkers.

To get a clearer understanding researchers studied the cardiovascular health of individuals with a genetic variant of the alcohol dehydrogenase 1B gene (a gene marker is typically more accurate than questionnaires used in observational studies). People who have his gene metabolize alcohol faster which causes symptoms such as nausea and facial flushing, and as a consequence are much less likely to drink.

Examining data from over a quarter of a million people researchers found that individuals with the gene had lower levels of alcohol consumption, better cardiovascular health (lower blood pressure, inflammatory biomarkers, adiposity measures, and cholesterol), and reduced risk of developing coronary heart disease. And those who consumed less alcohol had lower, not higher, risk of developing coronary heart disease regardless of whether they were light, moderate or heavy drinkers.

“These findings suggest that reductions of alcohol consumption, even for light to moderate drinkers, may be beneficial for cardiovascular health,” wrote the study investigators. “Our results therefore challenge the concept of a cardioprotective effect associated with light to moderate alcohol consumption reported in observational studies and suggest that this effect may have been due to residual confounding or selection bias.”

“There are few if any health benefits to drinking alcohol, even in moderation” commented Dr Tim Chico, Senior Clinical Lecturer and honorary Consultant Cardiologist at the University of Sheffield. While these results may seem contradictory, they are simply an evolution of our understanding. “To reduce your risk of heart disease you should walk to your greengrocer, not drive to your off-licence.”

Reference:

Holmes MV, Dale CE, Zuccolo L, et al. Association between alcohol and cardiovascular disease: Mendelian randomisation analysis based on individual participant data. BMJ. 2014 Jul 10;349:g4164. - link to free full-text