Aims: To investigate the relationship between three measures of alcohol consumption obtained simultaneously in a large cohort and the validated risk of coronary heart disease and all-cause mortality during follow-up.
Design: Prospective cohort study with median follow-up of 11 years.
Setting: The Whitehall II Cohort Study: London-based civil service.
Participants: A total of 10,308 (33% female) civil servants aged 35-55 years at baseline (1985-88).
Measurements: Self-reported volume of alcohol consumed during past week, frequency of drinking over past year, usual amount consumed per drinking session.
Main outcome measures: Coronary heart disease and all-cause mortality until 1999.
Findings: A U-shaped relationship was found between volume of alcohol consumed per week and outcome. Compared to those who drank moderately (10-80 g alcohol per week), non-drinkers and those drinking more than 248 g per week had approximately a twofold increased risk of mortality. The optimal frequency of drinking was between once or twice a week and daily, after adjustment for average volume consumed per week. Those drinking twice a day or more had an increased risk of mortality (male hazard ratio 2.44 95% CI 1.31-4.52) compared to those drinking once or twice a week. Drinking only once a month or only on special occasions had a 50% increased risk of mortality. The usual amount consumed per drinking session was not indicative of increased health risk in this cohort.
Conclusions: Epidemiological studies should collect information on frequency of drinking in addition to average volume consumed in order to inform sensible drinking advice.