Moderate Alcohol Intake and Risk of Functional Decline: The Health, Aging, and Body Composition Study

OBJECTIVES To investigate the prospective relationship between alcohol consumption and incident mobility limitation. DESIGN Cohort study. SETTING The Health Aging and Body Composition study, conducted in Memphis, Tennessee, and Pittsburgh, Pennsylvania. PARTICIPANTS Three thousand sixty-one adults aged 70 to 79 without mobility disability at baseline. MEASUREMENTS Incidence of mobility limitation, defined as self-report at two consecutive semiannual interviews of any difficulty walking one-quarter of a mile or climbing stairs, and incidence of mobility disability, defined as severe difficulty or inability to perform these tasks at two consecutive reports. Alcohol intake, lifestyle-related variables, diseases, and health status indicators were assessed at baseline. RESULTS During a follow-up time of 6.5 years, participants consuming moderate levels of alcohol had the lowest incidence of mobility limitation (total: 6.4 per 100 person-years (person-years); men: 6.4 per 100 person-years; women: 7.3 per 100 person-years) and mobility disability (total: 2.7 per 100 person-years; men: 2.5 per 100 person-years; women: 2.9 per 100 person-years). Adjusting for demographic characteristics, moderate alcohol intake was associated with lower risk of mobility limitation (hazard ratio (HR)=0.70, 95% confidence interval (CI)=0.55-0.89) and mobility disability (HR=0.66, 95% CI=0.45-0.95) than never or occasional consumption. Additional adjustment for lifestyle-related variables substantially reduced the strength of the associations (HR=0.85, 95% CI=0.66-1.08 and HR=0.81, 95% CI=0.56-1.18, respectively). Adjustment for diseases and health status indicators did not affect the strength of the associations, suggesting that lifestyle is most important in confounding this relationship. CONCLUSION Lifestyle-related characteristics mainly accounted for the association between moderate alcohol intake and lower risk of functional decline over time. These findings do not support a direct causal effect of alcohol intake on physical function.