A daily pint of dark beer such as Guinness may work as well as an aspirin in helping to prevent heart attacks, said researchers at the American Heart Association meeting in the US this week.
Researchers from Wisconsin University presented a study on dogs showing that dark beer significantly reduced markers fro platelet aggregation, which can lead to the dangerous clotting that causes heart attacks in heart disease patients.
The same results were not seen with lager however.
Several studies have shown that beer can, in moderate quantities, promote heart health. However it is not yet clear whether this is due to the effects of alcohol (similar results are seen with other alcoholic beverages) or the high antioxidant power of beer's ingredients.
The Wisconsin team compared the effect of light and dark beers on dogs with narrowed arteries, similar to those in humans with heart disease.
Platelet cGMP and cAMP levels were measured before and after beer administration in six randomly selected dogs from two groups of eight. These are surrogate markers for various cellular processes involved in platelet aggregation.
Afterwards the dogs were given epinephrine, previously shown to reverse the antithrombotic effects of drugs like aspirin. Only dogs administered dark beer were protected against the reversal of its antithrombotic effect. Platelet cGMP and cAMP levels were signifcantly elevated after dark beer but not at all after light beer.
The researchers concluded that polyphenolic content and composition of alcoholic beverages such as beer, may play a greater role in the observed beneficial effects on heart disease risk than the alcohol content.
Draft European legislation on nutrition and health claims will prevent any claims being made for the health benefits of alcoholic products.
The dark beer used in the study, Guinness, was at one time marketed with a 'good for you' slogan, but the manufacturers have long stopped using such advertising.