Two glasses of wine a night life-shortening

Two glasses of wine a night could cut two years off your life, the largest study of its kind has concluded.

Drinking a glass a night harms your life expectancy and much more than four bottles a week can take off five years, according to some of the first estimates of how soon alcohol will kill you.

Each daily alcoholic unit above recommended levels appears to shorten life as much as each daily cigarette, experts calculated.

The findings also go some way to resolving the question of whether alcohol protects the heart, as some studies have suggested, or damages it, as others indicate. Both appear to be true, with regular drinkers having a lower risk of non-fatal heart attacks but a higher risk of strokes and other heart-related deaths.

‘‘The key message of this research for public health is that, if you already drink alcohol, drinking less may help you live longer,’’ Angela Wood of the University of Cambridge, who led the study, said.

She looked at data on 600,000 drinkers in 19 countries, most in Britain, who were followed for up to 30 years, during which time 40,000 died and 39,000 suffered heart problems.

People’s risk of dying early started to increase if they drank more than about 100g of alcohol a week, equivalent to 12.5 units or five and a half 175ml glasses of 13 per cent ABV wine. Those who drank 44 units a week - less than four and a half bottles - were almost 50 per cent more likely to die early, according to results published in The Lancet.

For the first time Dr Wood’s team was able to use this data to calculate how much an average 40-year-old might shorten their life by drinking regularly. Those who drank between 12.5 and 25 units a week could expect to live six months less than someone drinking less. Compared with someone drinking less than 12.5 weekly units, those on 25 to 44 units a week would lose one to two years and those on more than 44 would lose four or five years.

Dr Wood cautioned these were averages: ‘‘Some will keel over at 41 and some will live to 100’’.

She said it was great that National Health Service guidelines had been cut to 14 units a week.

Because her study was so large, Dr Wood was able to tease out alcohol’s contradictory effect on the heart, with a 6 per cent lower risk of non-fatal heart attacks but a 14 per cent higher risk of stroke for each 12.5 weekly units. She said that this might be connected to the higher levels of ‘‘good’’ cholesterol drinkers tended to have but warned that the results were of little comfort to those who had convinced themselves that a nightly glass of red was good for the heart. ‘‘Yes, your risk of a nonfatal heart attack will decrease, but your risk of stroke, heart failure, non-fatal hypertensive disease increases,’’ she said.