A toast to thin blood.

Moderate consumption of alcohol may make a person's blood less likely to clot, scientists have found.

Studies have shown that people who drink regularly have a lower risk of heart attacks but a higher risk of bleeding strokes than do teetotalers. Since both of these health problems hinge on blood's clotting ability, Kenneth J. Mukamal of Beth Israel Deaconess Medical Center in Boston and his colleagues wondered whether alcohol affects platelets, the components in blood that cause it to clot.

The researchers studied the blood of 3,789 men and women who are enrolled in the Framingham Offspring Study, a decades-long investigation of risk factors for cardio vascular disease. Participants are examined and interviewed every 4 years to assess their health status and monitor their lifestyle practices, including drinking habits.

Mukamal's team found that the blood of people who consume 3 to 6 drinks weekly was less likely to clot in a test tube than was blood from nondrinkers. Platelets from the moderate drinkers were also less likely than those from nondrinkers to display a surface protein that makes them sticky. Consuming more than 6 drinks a week didn't further decrease these measures, the group reports in the October Alcoholism: Clinical and Experimental Research.