Two alcoholic drinks a day over a long period gave attack survivors a 42% lower risk of dying from heart disease than non-drinkers, researchers found.
Their risk of death from any cause was reduced by 14%.
But the benefits were seen only with “moderate’’ drinking. Higher consumption wiped out the survival gains and increased the chances of dying so they matched those of non-drinkers.
The findings are broadly in line with evidence that controlled drinking levels can protect the heart and arteries.
The findings are published in the online edition of European Heart Journal.
Moderate alcohol consumption was already known to be associated with a lower risk of heart disease and death in healthy people. But evidence has been lacking on the long-term effects of drinking before and after a heart attack.
The researchers took account of potential influencing factors such as body mass, smoking, age and medical history, that could have skewed the results.
While moderate drinking reduced the risk of death, men who consumed 30 grams or more of alcohol a day were as likely to die as non-drinkers.
“The adverse health effects of heavy drinking are well-known, and include high blood pressure, reduced heart function and reduced ability to break down blood clots,’’ said Dr Pai. “In addition, other studies have shown that any benefits from light drinking are entirely eliminated after episodes of binge drinking.
“Our results, showing the greatest benefit among moderate drinkers and a suggestion of excess mortality among men who consumed more than two drinks a day after a heart attack, emphasise the importance of alcohol in moderation.’’
The findings support European Society of Cardiology guidelines that alcohol consumption of 10 to 30 grams per day may improve long-term prognosis after a heart attack, said Dr Pai.
“If the men were already consuming moderate amounts, then it may be beneficial to continue consuming moderate amounts of alcohol after a myocardial infarction (heart attack),’’ she added. “However, because excessive alcohol intake is harmful, we recommend that patients discuss drinking alcohol in moderation with their physicians to individually assess their risks and potential benefits.’’
She stressed that the study looked only at men and the same results may not necessarily apply to women.
How the study was carried out
Researchers in the US monitored the progress of 1 818 men for up to 20 years after they had survived a first heart attack between 1986 and 2006.
The men were among participants in the US Health Professionals Follow-Up Study, a major health and lifestyle investigation. Every four years they were asked questions about their diet and alcohol intake.
Those who consumed between 10 and 29,9 grams of alcohol a day — the equivalent of two 125 millilitre glasses of wine, two bottles or cans of beer, or a shot of spirits — were classified as “moderate’’ drinkers.
Study leader Dr Jennifer Pai, from Brigham and Women’s Hospital and Harvard Medical School in Boston, said: “Our findings clearly demonstrate that long-term moderate alcohol consumption among men who survived a heart attack was associated with a reduced risk of total and cardiovascular mortality.
“We also found that among men who consumed moderate amounts of alcohol prior to a heart attack, those who continued to consume alcohol ‘in moderation’ afterwards also had better long-term prognosis.’’