This just in, and it's definitive (for now): People who drink alcohol in moderation — especially older people, women and non-Latino white people — are less likely to die of any cause than are teetotalers or people who consume heavy doses of alcohol either on occasion or in an average week.
In follow-up periods that hovered around eight years, moderate drinkers were no less likely than alcohol abstainers to die of cancer. But they were roughly a quarter less likely to die of heart disease or stroke than were people who never consumed alcohol.
Heavy drinkers fared slightly worse than moderate drinkers and never-drinkers in their likelihood of dying of any cause during the studies' follow-up periods. But it wasn't the risk of heart failure or heart attack that heavy drinkers drove up: it was cancer.
Heavy drinkers' odds of dying from cancer were roughly 45% higher than were the cancer-death odds of moderate drinkers.
In a meta-analysis — essentially an aggregation of studies reflecting the experience of 333,247 adults — researchers confirmed a long suspected (but much disputed) relationship between drinking and death: that, for most, consuming a little alcohol, even everyday, is better than drinking none. But throwing back too much is way worse than sipping just the right amount.
And what's the just-right amount of alcohol for health? Moderate drinkers are defined as men who consume, on average, no more than 14 servings of alcohol per week or women whose average consumption of alcohol is seven servings or fewer of alcohol per week. Here's what constitutes a serving (you might be surprised).
Binge drinking once a week or more (typically, drinking four or more servings of alcohol in two hours or less for women, or five or more for men) increased drinkers' odds of dying during the study periods by about 16%, largely by driving cancer rates up.
Alcohol consumption bedevils doctors, public health experts and patients alike, what with all the stigma, sanctimony, lying and uncertainty that surrounds this most common of vices. Patients lie about how much they drink. Unless they see clear signs of alcohol-induced damage in a patient, a physicians are hard-pressed to guess. And claims and counter-claims abound about alcohol's impact on health.
The World Health Organization, citing alcohol's link to cancer, recommends against any consumption of alcohol at all. That may be reasonable, given that 3.3 million deaths, or 5.9% of global deaths in 2012, were attributed to alcohol consumption. But it may overlook the fact that, for those who can do so in moderation, alcohol consumption may positively influence health — and cardiovascular health in particular.
How alcohol influences health at different doses is also not well understood. Some research suggests that a modest intake of alcohol may reduce blood pressure, improve the function of blood vessels and — in the case of wine consumption at least — may introduce plant-based chemicals that scavenge toxins.
Aside from driving up risks of accidents and violence, excessive alcohol consumption may nudge cancer risk, especially for breast, colorectal and oral cancers, up by increasing inflammatory processes, changing hormonal balances, or suppressing immunity.
The newest research, published Monday in the Journal of the American College of Cardiology, does find some key differences by gender, ethnicity and age.
Heavy drinking drove up rates of all-cause mortality, and of cancer mortality, in men. But the same effect was not seen in women.
Non-Latino whites appeared to benefit from moderate alcohol consumption. But non-Latino blacks did not.
The protective effects of moderate alcohol consumption was more pronounced in people 60 and older than among people 40 to 59. And among younger adults — those 18 to 39 — moderate alcohol consumption didn't drive down death rates at all.
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