The short- and long-term harmful effects of excessive alcohol consumption are well documented, but certain studies highlight potential benefits associated with more moderate or even light drinking.
And yet, the World Health Organization (WHO) recently reiterated that “when it comes to alcohol consumption, there is no safe amount that does not affect health”.
As a result, scientists are now seeking to understand and determine the mechanisms behind alcohol’s potential protective effects, in order to replicate them in ways that are less harmful to health.
That’s what researchers at Massachusetts General Hospital in the United States have set out to achieve, revealing for the first time a possible link between light to moderate alcohol consumption and heart health.
Published in the Journal of the American College of Cardiology, their research suggests that low levels of alcohol may reduce stress signals in the brain over the long term and, by extension, reduce the risk of cardiovascular disease.
“We are not advocating the use of alcohol to reduce the risk of heart attacks or strokes because of other concerning effects of alcohol on health,” senior author and cardiologist Dr Ahmed Tawakol pointed out.
More than 50,000 people took part in this two-stage study. Researchers first assessed the link between light to moderate alcohol consumption and cardiovascular events, then looked at a subset of 754 participants who underwent brain imaging to confirm or refute the effect of this consumption on stress-related neuronal activity.
As a result, the scientists observed a reduction in stress signals in the amygdala complex – a brain region whose role is to manage fear or anxiety – of participants who consumed alcohol lightly or moderately.
Secondly, the researchers looked at the backgrounds of these same participants and found a lower risk of heart attack and stroke. They attributed this phenomenon to changes in the brain observed in those who consumed low or moderate amounts of alcohol.
“When the amygdala is too alert and vigilant, the sympathetic nervous system is heightened, which drives up blood pressure and increases heart rate, and triggers the release of inflammatory cells,” Ahmed explained.
“If the stress is chronic, the result is hypertension, increased inflammation, and a substantial risk of obesity, diabetes and cardiovascular disease.”
This study has its limits, however, not least because it also shows that alcohol consumption increases the risk of cancer, regardless of the amount consumed. And that’s not all, since consuming more than 14 drinks a week was also associated with a higher risk of heart attack and poor cognitive health.
“We wanted to understand how light to moderate drinking reduces cardiovascular disease, as demonstrated by multiple other studies. And if we could find the mechanism, the goal would be to find other approaches that could replicate or induce alcohol’s protective cardiac effects without the adverse impacts of alcohol,” Ahmed concluded.