A beer a day may help keep heart attacks away, according to a group of Israeli researchers. In preliminary clinical studies of a group of men with coronary artery disease, the researchers showed that drinking one beer (12 ounces) a day for a month produced changes in blood chemistry that are associated with a reduced risk of heart attack.
The study adds to growing evidence that moderate alcohol consumption may reduce the risk of heart disease, one of the leading causes of death in the developed world. The findings are scheduled to appear in the 29 January edition of the Journal of Agricultural and Food Chemistry.
Changes observed in the blood of the test participants following beer-drinking include decreased cholesterol levels, increased antioxidants and reduced levels of fibrinogen, a clot-producing protein, reported the researchers.
The study also showed, for the first time, that drinking alcoholic beverages causes structural changes in fibrinogen that make the clotting protein less active, said lead investigator Dr Shela Gorinstein, a researcher with The Hebrew University of Jerusalem in Israel. Characterising these structural changes of fibrinogen may one day serve as a new diagnostic indicator of heart attack risk, along with known risk indicators such as blood cholesterol and antioxidant levels, she said. The team added that further studies on this area are needed.
Forty-eight men, aged 46-72, with coronary artery disease were divided into two groups. Individuals in one group drank the equivalent of 12 ounces (one standard can or bottle) of beer a day for 30 consecutive days, while the others drank mineral water. Both groups ate a similar diet, rich in fruits and vegetables, during this period.
In 21 of the 24 patients in the beer-drinking group, the researchers found positive changes in blood chemicals that are associated, on the basis of previous studies by Gorinstein and others, with a decreased heart attack risk. These changes include a decrease in "bad" cholesterol, an increase in "good" cholesterol, an increase in antioxidant levels, and a decrease in levels and activity of fibrinogen.
These changes, most likely produced by the relatively high polyphenol content of beer, were generally not seen in the blood of the non-beer-drinking group, the researchers said.
No heart attacks occurred among either patient group during the study period, they added. The patients are currently being monitored to evaluate long-term heart attack risk and survival rates, but results are not yet available.
Although the beer used in this study was a standard pale lager (5 per cent alcohol by volume), other beers are likely to have a similar effect, the researchers believe. A growing number of studies have linked moderate alcohol consumption to a reduced risk of coronary heart disease and heart attack. Epidemiological studies have shown that moderate drinkers have a lower risk of heart disease than both heavy drinkers and non-drinkers.
Both polyphenol and alcohol are thought to contribute to this heart-healthy effect. Based on previous studies, it appears that polyphenols play the major role in this effect, while alcohol plays a lesser role, said Gorinstein. Beverage type may also play a role in heart disease risk - red wine is thought to offer more heart-protective effects than white wine and beer. This has been attributed to the wine's high content of polyphenols compared with lower amounts in the other beverages, according to researchers.
An association between moderate drinking and lowered heart disease risk does not necessarily mean that alcoholic beverages are the only cause, however. Some studies suggest that lifestyle factors, such as diet and exercise, may help account for some of the association between lower heart disease risk and drinking. Until this association between alcohol and lower heart disease risk is clarified, people who choose to drink alcohol are advised to do so in moderation, said the researcher.
Funding for the study was provided by The Hebrew University.