India, Dec. 19 -- Milk has long been at the center of diet debates, praised by some and blamed by others for heart trouble. A long-running study out of South Wales offers another take. Tracking older men over two decades, researchers found no convincing evidence that drinking milk increases the risk of heart disease or stroke. The research comes from the Caerphilly cohort, a representative population sample of men living in South Wales who were between 45 and 59 years old when the study began in the late 1970s and early 1980s.

Participants were asked to weigh and record everything they ate and drank for seven consecutive days.

Researchers then followed the group for 20 years, collecting detailed records of deaths, strokes, and heart dis...