A glass of wine may be good for the heart—but may promote some cancers. Scientists have now figured out what's behind that sobering observation. New findings suggest that alcohol encourages blood vessels to infiltrate and nourish nascent tumors.
Researchers have long known that drinking alcohol is a risk factor for stomach, liver, and breast cancers, among others. Previous studies prompted a host of theories—for example, that heavy drinking displaces other nutrients in the diet or that acetaldehyde, a metabolite of alcohol, acts as a carcinogen—but they haven't clarified the alcohol-cancer connection.