Moderate alcohol drinking may reduce risk of death in men who have survived a first heart attack, say researchers.
A study in the USA found that, having survived a first heart attack, men who drank approximately two alcoholic drinks a day over a long period of time had a 14 percent lower risk of death from any cause and a 42 percent lower risk of death from cardiovascular disease than non-drinkers.
Dr Jennifer Pai, assistant professor of medicine at Channing Laboratory, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, and a research associate at Harvard School of Public Health is the first author of the study.
“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,” Pai said.
Although it is already known that moderate alcohol consumption is associated with a lower risk of heart disease and death in the healthy population, so far it has been unclear whether it may also be related to lower death rates among people who have established heart disease. Until now, there has been no prospective study that has measured alcohol drinking both before and after a heart attack, with long-term follow-up.
Dr Pai and her colleagues looked at a subset of 1818 men in the Health Professionals Follow-up Study who had survived a first heart attack between 1986 and 2006. The researchers followed them for up to 20 years from the time of the heart attack. During this period 468 men died.
After adjusting for various factors that could affect the results, such as smoking, body mass index, age and medical history, the researchers found that the men who consumed approximately two alcoholic drinks a day after their first heart attack had a lower risk of death from any cause than the non-drinkers. The type of drink did not affect the results.
When they looked at levels of alcohol consumption before and after the heart attack, they found that the majority of men did not change their drinking habits, and also that those who drank before and afterwards tended to have a lower risk of death than the non-drinkers. However, due to the smaller numbers in this analysis, the results were not statistically significant.
There was a “U” shape to the results, which showed that men who drank the most (30g or more a day) had a risk of death from any cause that was similar to the 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. In addition, other studies have shown that any benefits from light drinking are entirely eliminated after episodes of binge drinking,” said Dr Pai.
“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,” she noted.
The study has some limitations, including the fact that reporting alcohol intake via questionnaires might lead to measurement errors, and that the way heart attacks are treated has changed over the past 20 years. However, the researchers do not believe these affect the validity of the results. In addition, the findings only relate to drinking in men.
“Our study was only among men, so we cannot extrapolate to women. However, in all other cases of alcohol and chronic disease, associations are similar except at lower quantities for women. Thus, an association is likely to be observed at 5-14.9g per day, or up to a drink a day for women,” Dr Pai added.
The findings were published online in the European Heart Journal.