Alcohol consumption and cognitive decline in early old age

OBJECTIVE To examine the association between alcohol consumption in midlife and subsequent cognitive decline. METHODS Data are from 5,054 men and 2,099 women from the Whitehall II cohort study with a mean age of 56 years (range 44-69 years) at first cognitive assessment. Alcohol consumption was assessed 3 times in the 10 years preceding the first cognitive assessment (1997-1999). Cognitive tests were repeated in 2002-2004 and 2007-2009. The cognitive test battery included 4 tests assessing memory and executive function; a global cognitive score summarized performances across these tests. Linear mixed models were used to assess the association between alcohol consumption and cognitive decline, expressed as z scores (mean = 0, SD = 1). RESULTS In men, there were no differences in cognitive decline among alcohol abstainers, quitters, and light or moderate alcohol drinkers (<20 g/d). However, alcohol consumption ≥36 g/d was associated with faster decline in all cognitive domains compared with consumption between 0.1 and 19.9 g/d: mean difference (95% confidence interval) in 10-year decline in the global cognitive score = -0.10 (-0.16, -0.04), executive function = -0.06 (-0.12, 0.00), and memory = -0.16 (-0.26, -0.05). In women, compared with those drinking 0.1 to 9.9 g/d of alcohol, 10-year abstainers showed faster decline in the global cognitive score (-0.21 [-0.37, -0.04]) and executive function (-0.17 [-0.32, -0.01]). CONCLUSIONS Excessive alcohol consumption in men (≥36 g/d) was associated with faster cognitive decline compared with light to moderate alcohol consumption.