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

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.