"This study has shown that drinking alcohol at levels which were believed to be safe is actually linked with lower life expectancy and several adverse health outcomes", said Dr Dan Blazer, the report's co-author.
A sweeping global study of alcohol consumption has found no overall health benefits from moderate drinking and calls into question the US guidelines that say men can safely drink twice as much as women. This is equivalent to drinking no more than 6 pints of average-strength beer (4% ABV) or 7 medium-sized glasses of wine (175ml, 12% ABV) a week.
The guidelines recommend women over 21 drink no more than one drink per day, but this rises to two drinks for men. However, risk of non-fatal heart attacks dipped with more alcohol. The safe lower limit is 5 glasses per week.
The new research does not suggest that a drinker who has just a little too much every day is falling off an epidemiological cliff.
Around half of the almost 600,000 participants said they consumed the equivalent of more than of seven alcoholic drinks per week, while almost 10 percent reported drinking more than 25.More news: Russian court bans access to Telegram messenger
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Most Canadians drink alcohol and, as a country, we consume more than 50 per cent above the world average.
The findings challenge the widely held belief that moderate drinking is beneficial to cardiovascular health, and support the UK's recently lowered guidelines.
It was published in the peer-reviewed medical journal The Lancet on an open-access basis so is free to read online.
The researchers point out that there is no thresholds below which lower alcohol consumption stopped being associated with disease risk but that the threshold for lowest risk was 100g per week.
In numerous individual studies included in the meta-analysis, the participants were asked only once about how much alcohol they drank - and people are notoriously bad at accurately reporting their drinking.
"Secondly, there has been a fiction, used by the alcohol industry to maintain nearly unrestrained advertising for its products, that small quantities of alcohol are beneficial, even healthy (reducing the risk of cardiovascular disease)".
The authors note that the different relationships between alcohol intake and various types of cardiovascular disease can be explained, at least in part, by the effect of alcohol consumption on elevated blood pressure and on factors related to lipoprotein cholesterol. Abstainers and former drinkers are often much less healthy than those in the general population who drink moderately, but they've often been included in studies comparing drinkers to non-drinkers.