Genetic risk, adherence to a healthy lifestyle, and cognitive decline in African Americans and European Americans.

ABSTRACT

INTRODUCTION: We investigated the role of genetic risk and adherence to lifestyle factors on cognitive decline in African Americans and European Americans. METHODS: Using data from the Chicago Health and Aging Project (1993-2012; n = 3874), we defined the genetic risk based on presence of apolipoprotein E (APOE) ε4$\varepsilon 4$ allele and determined a healthy lifestyle using a scoring of five factors non-smoking, exercising, being cognitively active, having a high-quality diet, and limiting alcohol use. We used linear mixed-effects models to estimate cognitive decline by genetic risk and lifestyle score. RESULTS: APOE  ε4$\varepsilon 4$ allele was associated with faster cognitive decline in both races. However, within APOE  ε4$\varepsilon 4$ carriers, adherence to a healthy lifestyle (eg., 4 to 5 healthy factors) was associated with a slower cognitive decline by 0.023 (95% confidence interval [CI] 0.004, 0.042) units/year in African Americans and 0.044 (95% CI 0.008, 0.080) units/year in European Americans. DISCUSSION: A healthy lifestyle was associated with a slower cognitive decline in African and European Americans.