Do white and red wine, the latter touted for its many health benefits, really stave off heart disease? The jury is still out on that one.
"It's complicated," says Juergen Rehm, director of social and epidemiological research at Centre for Addiction and Mental Health (CAMH), who conducted
the meta-analysis into the link between alcohol consumption and heart disease.
"While a cardioprotective association between alcohol use and ischaemic heart disease exists, it cannot be assumed for all drinkers, even at low levels of intake," says Rehm, the journal Addiction reports.
Ischaemic heart disease (reduced blood supply to heart) is a common cause of illness and death in the Western world, according to a CAMH statement.
Symptoms include angina, heart pain, and heart failure. Based on 44 studies, the analyses used 38,627 ischaemic heart disease events (including deaths) among 957,684 people.
"We see substantial variation across studies, in particular for an average consumption of one to two drinks a day," says Rehm. The protective association may vary by gender, drinking patterns, and the specific health effects of interest.
Even at low levels, alcohol intake can have a detrimental effect on many other disease outcomes, including on several cancers.
"Even one drink a day increases risk of breast cancer, for example," says Rehm. "However, with as little as one drink a day, the net effect on mortality is still beneficial. After this, the net risk increases with every drink."
"If someone binge drinks even once a month, any health benefits from light to moderate drinking disappear."
Binge drinking is defined more than four drinks on one occasion for women, and more than five for men.
"Findings from this study support current low-risk drinking guidelines, if these recognize lower drinking limits for women."