Light to moderate alcohol consumption may lower the risk of heart disease because it leads to long-term reductions in stress signalling in the brain, new research claims.
But cardiologists warn the cardiac benefits do not mean we should ignore other dangers of alcohol.
“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,” said cardiologist Ahmed Tawakol, lead author of the study by investigators from Massachusetts eneral hospital.
Researchers wanted to understand exactly how light to moderate drinking (one drink a day for women and between one and two drinks a day for men) reduces cardiovascular disease, as demonstrated by multiple other studies.
If the mechanism was understood, the goal would be to find other approaches replicating alcohol’s protective effects without the adverse impacts, said Tawakol, MD, co-director of the Cardiovascular Imaging Research Center at the hospital.
The study, led by co-authors Kenechukwu Mezue and Michael Osborne, the findings of which are published in the Journal of the American College of Cardiology, looked at 50,000 individuals enrolled in the Mass General Brigham biobank.
Adjusting for genetic, clinical, lifestyle, and socioeconomic confounders, they found a reduction in the risk of cardiovascular disease events in light to moderate drinkers.
They then examined a subset of 754 individuals, who had previously undergone brain imaging, to determine the effect of light/moderate alcohol consumption on resting stress-related neural network activity.
The brain imaging showed reduced stress signalling in the amygdala, the brain region associated with stress responses, in individuals who were light to moderate drinkers compared with those who abstained from alcohol or who drank little.
It’s long been known that alcohol reduces the amygdala’s reactivity to threatening stimuli while individuals are drinking, but this study is the first to indicate light to moderate alcohol consumption has longer-term neurobiological effects in dampening activity in the amygdala, which may have a significant downstream impact on the cardiovascular system.
“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,” says Tawakol. “If the stress is chronic, the result is hypertension, increased inflammation, and a substantial risk of obesity, diabetes, and cardiovascular disease.”
Finally, investigators found that, within the 50,000-patient sample, light to moderate drinking was associated with nearly double the cardiac-protective effect in individuals with a history of anxiety compared with others.
The study also showed that any amount of alcohol increases the risk of cancer. And at higher amounts of alcohol consumption – more than 14 drinks a week – heart attack risk started to increase while overall brain activity started to decrease (which may be associated with adverse cognitive health), it said.
