More evidence that moderate drinking may benefit the heart

Two large studies published in June, one covering 52 countries around the globe and the other from Scandinavia, link low-to-moderate alcohol consumption to reduced risk of heart attack or a life-threatening flaw in the main artery from the heart.

The protective effects of moderate drinking were not universal across Asia. And it’s not clear whether all types of alcohol offer the same benefits - both papers urge further exploration of that and other questions. But both also find increased risk of harm when drinking goes from moderate to heavy.

“There is now solid evidence that alcohol, when consumed on a regular basis and at low volumes (up to one drink for women and two drinks for men daily), confers protection against cardiovascular disease, whereas regular amounts of more than four to five drinks daily and heavy episodic drinking have (the) opposite effects,” write Drs. Stefan Kiechl and Johann Willeit, neurologists at Innsbruck Medical University in Austria, in an editorial in the journal Circulation.

One of the new studies looked at drinking and risk of experiencing abdominal aortic aneurysm (AAA), a “ballooning” of the main blood vessel from the heart that delivers blood to the trunk and lower body.

The condition kills about 11,000 Americans each year and contributes to the death of 17,000 more, according to the Centers for Disease Control and Prevention. Men, especially those over age 60, are most likely to have AAA. Smoking and high blood pressure can increase the risk, and if the aneurysm ruptures, it can be life threatening.

Heart attack, which affects about 1.5 million people in the U.S. each year, is subject to many of the same risk factors and also can be life threatening.

For the heart attack study, researchers used data from 52 countries to compare 12,000 cases of first heart attacks with 15,500 similar people who did not have a heart attack. Trained staff administered alcohol use questionnaires to heart attack victims and the comparison group.

Compared to not drinking at all, current alcohol use was linked to a 13 percent lower risk of heart attack, on average, in almost all regions, with the exception of South Asian countries including India, Sri Lanka, Pakistan and Bangladesh.

In other regions, the protective association went away when alcohol consumption increased beyond four drinks per week.

Having six or more drinks in the past 24 hours was associated with a 40 percent increased risk of heart attack, especially for people over age 65.

“There have been several postulated mechanisms by which low levels of alcohol use could protect against heart attack and by which heavy alcohol use could increase the risk of heart attack,” said lead author Dr. Darryl P. Leong of the Population Health Research Institute at McMaster University and Hamilton Health Sciences in Canada.