People who drank up to two drinks a day reduced their stroke risk by 45% compared to non-drinkers
Abundant research has been conducted recently on the subject of alcohol and its
protective role in heart disease. Most of the research focuses on exactly how much alcohol
consumption is considered protective, and the point at which its consumption becomes
harmful rather than beneficial. Another important question is whether some types of
alcohol, such as red wine, provide more benefit than others. Should people with heart
disease drink alcohol, and if so, how much? What about people who are at risk of
developing heart disease? We have summarized below various research findings on these
topics to help provide some answers to these questions. (See Summary
Overview and HeartInfo Editorial Comments
One recent study was led by researchers from Boston's Brigham and Women's Hospital and Harvard Medical School and was conducted over a 10.7 year period. The study included over 22,000 men in the Physicians Health Study ranging in age from 40 to 84. Results of the study, published in January in the Archives of Internal Medicine, revealed that men who drink moderately (two to six alcoholic drinks per week) are healthier overall than heavy drinkers (two or more drinks per day) and light drinkers (less than one drink per week). Of the 1,206 deaths, 394 were from cardiovascular causes, 488 from cancer, and 324 from other causes. The researchers, led by Dr. Carlos A. Camargo Jr. found that compared with light drinkers, the risk of dying from all causes was 28% lower in men who drank two to four drinks per week, 21% lower in men who drank five or six drinks per week and 51% higher for men who were considered heavy drinkers.
The decreased risk of death among moderate drinkers was mostly attributed to a 34% to 53% reduction in the risk of dying from cardiovascular disease. Researchers also found that heavy drinking caused no significant increase in heart disease deaths. However, heavy drinkers faced a doubling of risk with respect to cancer death.
The researchers in this study noted that the subjects in the study who were heavy drinkers seemed to share several qualities: they "tended to be older, smoke more, and be more likely to have hypertension" than any other group. The researchers further noted that since the study included men only, its findings are only applicable to men for the following reason: it is difficult to make direct comparisons between the sexes given the complication of factoring in the risk of breast cancer for women.
In another study conducted by the Northern Manhattan Stroke Study and reported by the American Heart Association on February 7, 1997, researchers examined alcohol consumption in the 12 months preceding a stroke in 423 patients and compared them to alcohol consumption over a 12 month period for 793 people who did not have a stroke. They matched the groups for age, race and sex and also adjusted the results for other stroke risk factors.
In this study, researchers found that occasional drinkers (defined as drinking less than one drink per month) had a 62% lower risk of stroke than non-drinkers. People who drank up to two drinks a day reduced their stroke risk by 45% compared to non-drinkers. However, consumption of more than five drinks a day tripled the risk of stroke. The researchers also found that heavy drinkers who cut back their drinking habits enjoyed the same benefits as lighter drinkers proving that changing habits can have an impact in reducing stroke risk.
The American Heart Association (AHA) issued a science advisory in their December 1, 1996 issue of the journal Circulation advising that the health benefits of alcohol are limited to one to two drinks a day. Dr. Thomas A. Pearson, head of AHA's nutrition committee, further warns that heavy drinking can cause a variety of health problems including high blood pressure and stroke, heart muscle disorders, many kinds of cancer, liver and pancreas disease, along with accidents, homicide and suicide. He advises that people whose medical and social problems are exacerbated by drinking should abstain completely.
As an indication of the paradox of the alcohol debate, Dr. Pearson notes that alcohol-related diseases account for 100,000 deaths in the U.S. annually. However, if current drinkers stopped drinking, heart disease related deaths he estimates would increase by 80,000 each year in the U.S.
There have been further debates regarding whether certain types of alcohol are better than others. According to two studies reported by Reuters on March 22, 1996, the protective effects of alcohol on coronary heart disease (CHD) are not contingent upon the kind of alcohol consumed. Researchers believe that all types of alcohol reduce the risk of CHD at least in part by reducing serum levels of LDL (bad) cholesterol. Alcohol raises the HDL (good) cholesterol as well, which could play some role in protecting against heart disease.
However, conflicting research has indicated that the antioxidants in red wine may be more protective than other types of alcohol in preventing atherosclerosis. In a study conducted in Sao Paulo, Brazil and presented at the 18th Congress of the European Society of Cardiology in Birmingham, rabbits were fed a high cholesterol diet and either given red wine, red wine without the alcohol, or no wine at all. After three months, the aorta (the largest artery) was examined for fatty plaques . Researchers found that in the rabbits not given any alcohol, 60% of their aortas were covered with fatty plaques; this declined to 50% in the rabbits fed the non-alcoholic red wine; and to 40% in the rabbits given red wine. However, the researchers could not explain these results as all of the rabbits had 20 times the normal amounts of LDL (bad) cholesterol and total cholesterol in their blood after eating the high fat diet. Their HDL (good) cholesterol levels were unaffected.
The researchers speculate that flavonoids, present both in fruits and vegetables and
red wine, "act as antioxidants and may prevent the oxidation of LDL cholesterol, a
step that facilitates plaque formation". Of course, this study did not compare red
wine to other forms of alcohol, so the question remains unanswered. Furthermore, all
animal studies must be interpreted with great caution regarding extrapolation to humans
and clinical recommendations. The concept that red wine has protective properties not
found in other types of alcohol is attractive but remains unproven. The data suggest, in
contrast, that all forms of alcohol are equally protective.
In summary, the issue of alcohol and heart disease is far from settled. Nevertheless, some generalizations can be safely made: 1) drinking alcohol in moderation (fewer than two drinks a day) may decrease risk of heart disease; 2) this effect appears to be true for all types of alcohol and not limited to red wine; 3) if you currently do not drink, it is not advisable that you start--alcohol should not be used as a medication; 4) Discuss your drinking habits with your doctor.
HeartInfo Editorial Comment:
"Should I drink red wine (or other alcohol) for my heart?" Some form of this question is asked of physicians very frequently, and is answered in many different ways. Our favorite answer is: "Do you like to drink red wine (or other alcohol)?" If the answer is yes and if you do not have medical and/or social problems that are exacerbated by alcohol, a few drinks per week would seem a reasonable indulgence that may happen to have a positive benefit. On the other hand, if the answer is no, it is not advised that you begin drinking purely for medicinal value. There are too many other proven ways to reduce risk of heart disease.
American Heart Association Press Release February 7, 1997; American Medical Association's Archives of Internal Medicine, January 13, 1997; Reuters January 13, 1997, Reuters December 9, 1996; Circulation, December 1, 1996; Reuters August 30, 1996; Reuters March 22, 1996.