Bloomberg | Mar 23, 2016,
It's an irresistible headline: People who drink alcohol in moderation actually live longer than those who abstain entirely. However, a study has shown the fact suffers from a big flaw: The "abstainers" category includes people who used to drink but have stopped. They may be inherently less healthy, than people who drink in moderation. That doesn't mean that drinking in moderation causes people to live longer.
Researchers at University of Victoria in British Columbia examined 87 studies on the relationship between alcohol and mortality that involved nearly four million people. Only 13 of them strictly separated life-long non-drinkers from people who used to drink or those who imbibe occasionally. Analysing the studies that were free from "abstainer bias" showed no significant benefits for moderate drinkers compared to lifetime abstainers.
And when they compared moderate drinkers with those who consumed alcohol less than once a week, they found no benefit to drinking more often, said Tim Stockwell, lead author of the paper.
Some scholars have been questioning the purported health benefits of alcohol for years. The debate is complicated because most of the evidence on the long-term effects of alcohol - or diet, exercise, and other lifestyle factors, for that matter - is observational. Scientists examine people's behaviour to try to find associations with different health outcomes.
That contrasts with experimental research, which is the method used to test new drugs: People are randomly assigned to get either the drug or a placebo, and neither patients nor the scientists know which is which. Such double-blind, randomised control trials are designed to reduce biases that could inadvertently skew the results...
"As an intoxicating, addictive, toxic, carcinogenic drug, alcohol is not a good choice as a therapeutic agent," wrote Jennie Connor, chair in preventive and social medicine at the University of Otago. Emanuel Rubin, a pathologist, suggested the evidence was strong enough and doctors should consider recommending patients to start drinking. "There's a protective effect to moderate alcohol consumption for several health conditions, like coronary artery disease and stroke." bloomberg