One in three adults will experience stroke or develop dementia in their lifetime, underscoring the need to identify modifiable factors to delay or prevent disease. Alcohol, a common exposure in most populations, may confer cardiovascular benefits at light-to-moderate doses. Its association with stroke and cognitive function is uncertain. This dissertation aims to estimate the associations between mid-life alcohol consumption and incident stroke and rate of cognitive decline using data from the Atherosclerosis Risk in Communities Study, a biracial population-based cohort of 15,792 adults aged 45-64 at baseline with >20 years of follow-up. Alcohol consumption was self-reported as usual drinks per week; categorized as never, former, light (≤3), moderate (4-17), and heavier (≥18). One-third of participants were light drinkers, roughly one-fifth each were moderate, never and former drinkers and only 4% reported heavier consumption. Suspected strokes were obtained through self-report and hospital surveillance, validated using medical records, and adjudicated by physician experts. Light and moderate consumption were not strongly associated with ischemic stroke (HR=0.98, 95% CI 0.79-1.21; 1.06, 0.84-1.34) while heavier drinking was associated with a 31% increased rate relative to abstention in Cox proportional-hazard regression. Specification of intake with quadratic splines did not support a J-shaped relationship with stroke; we noted a roughly linear relative increase across intake. Moderate, but not light, consumption increased hemorrhage rates. Cognitive status was assessed at visits 2, 4, and 5 using three validated tests. Linear regression with generalized estimating equations estimated the difference in 20-year decline by alcohol intake. We used multiple imputation with chained equations to address informative attrition in sensitivity analysis. Global 20-year cognitive change did not differ between light drinkers and abstainers (0.019 z-score units; 95% CI -0.032, 0.070) and was somewhat faster for heavier drinkers (-0.041; -0.0152, 0.070). No consistent pattern in 20-year change was observed across tests, but effects were somewhat larger on tests of verbal fluency and executive function. Light-to-moderate consumption at mid-life was not associated with reduced stroke risk or slower cognitive decline compared with abstention over 20 years of follow-up in the ARIC study. Heavier consumption tended to increase the risk for both outcomes.