Alcohol intake in middle age and risk of cardiovascular disease and mortality: accounting for intake variation over time.

Moderate alcohol consumption is associated with a decreased risk of cardiovascular disease. However, the impact of variation in alcohol intake over time on estimated risk relations has not been adequately addressed. In this study, 6,544 middle-aged British men without previous cardiovascular disease were followed for cardiovascular events and all-cause mortality over 20 years from 1978/1980 to 1998/2000. Alcohol intake was ascertained at regular points throughout the study. A total of 922 men had a major coronary event within 20 years, 352 men had a stroke, and 1,552 men died of all causes. Baseline alcohol intake displayed U-shaped relations with cardiovascular disease and all-cause mortality, with light drinkers having the lowest risks and nondrinkers and heavy drinkers having similarly high risks. However, the nature of these relations changed after adjustment for intake variation; risks associated with nondrinking were lowered, and risks associated with moderate and heavy drinking increased. Regular heavy drinkers had a 74% higher risk of a major coronary event, a 133% higher risk of stroke, and a 127% higher risk of all-cause mortality than did occasional drinkers (these estimates were 8%, 54%, and 44% before adjustment for intake variation). The findings suggest that considerable caution may be needed before any recommendations regarding acceptable limits of alcohol consumption are made.