The volume of alcohol consumption may have a significantly different effect on heart and stroke risk in men and women, according to a study in Japan.
Researchers analysed data from a survey of 34,776 men and 48,906 women (ages 40 to 79) selected from the larger Japan Collaborative Cohort Study (JACC) to determine the association of alcohol use with the risks of stroke and heart disease. Participants who had not experienced cancer, stroke or heart disease before the study completed questionnaires about their lifestyles and medical histories and provided information about their drinking.
Researchers calculated the risks and benefits of alcohol consumption after adjusting for age and several other risk factors, including smoking, weight, body mass index, the presence of high blood pressure or diabetes, exercise habits, stress, education and diet. During a 14.2-year follow-up, 1,628 participants died from stroke and 736 died from heart disease.
Men who reported drinking heavily (at least 46 grams of alcohol per day) at the time of the survey had a 19% lower risk of dying from coronary heart disease than nondrinking men.
In contrast, women who drank heavily were four times as likely to die of heart disease than nondrinking women. Light drinking (less than 23 grams of alcohol per day) was associated with a lower risk of heart disease death in women by 17%; while intake between 23 and 46 grams per day was associated with an increased risk of 45%.
In men, heavy alcohol use was associated with an increased risk of death from all types of stroke by 48%. The risk of hemorrhagic stroke (caused by a blood vessel bursting in the brain) was increased 67%. The risk of ischemic stroke (caused by a blocked blood vessel in the brain or leading to it) was higher by 35%.
In women, heavy alcohol use was associated with a higher risk of stroke death by 92%. Hemorrhagic stroke death risk was increased by 61%. The risk of ischemic stroke death was increased 2.43 times.
Only 15% of women in JACC drank any alcohol, far less than the 45.9% of U.S. women who reported using alcohol in 2005.
Before this study, evidence suggested that light-to-moderate alcohol consumption might be associated with a lower risk of cardiovascular disease in women. But data on heavy drinking was limited and the question had not been addressed in an Asian country, where both drinking and heart disease are less common.
“One limitation of the study is that, in Japanese culture, there are social restrictions against women drinking as they get older,” H. Iso co-author of the study stated. “In that culture, the women who do drink may have different types of jobs or other aspects of their lifestyle that may help explain the excess risk as well as the alcohol exposure itself.”
Iso suggested that more research could help determine how alcohol affects cardiovascular risk.
Source: American Heart Association (2008, July 13).