Abstract
BACKGROUND: Dietary choline intake has been associated with a lower risk of cognitive dysfunction, lessened brain white-matter hyperintensity volume, and a reduced risk of incident dementia. OBJECTIVES: This study aims to evaluate the relationship between dietary choline intake and risk of clinical diagnosis of Alzheimer's dementia (AD) in participants enrolled in the Rush Memory and Aging Project prospective cohort. METHODS: Participants who were free of AD at baseline and had completed ≥1 food frequency questionnaire were included in the present analyses. Clinical AD was assessed among participants annually using a 3-stage process of neurological examinations and standardized diagnostic criteria. Dietary choline intake was quantified using the United States Department of Agriculture Database for the Choline Content of Common Foods. Multivariable Cox proportional hazard models were used to assess risk of incident of AD by quantiles of dietary choline intake. Mixed-effect Poisson regression models were used to investigate potential nonlinear relationships. RESULTS: Mean baseline age of the study participants (N = 991) was 81.4 (±7.2) y. During a mean follow-up of 7.67 y, 266 participants (27%) were clinically diagnosed with AD (incident rate = 38/1000 person-year). In the fully adjusted model, compared with the lowest quantile of dietary choline intake, consumption of 200-250, 251-300, 301-350, and >350 mg/d were associated with a 23% [hazard ratio (HR): 0.73; 95% confidence interval (CI): 0.45, 1.17; P = 0.10], 40% (HR = 0.60; 95% CI: 0.60, 0.98; P = 0.04), 38% (HR = 0.62; 95% CI: 0.36, 1.07; P = 0.09), and 51% (HR: 0.49; 95% CI: 0.25, 0.95; P = 0.04) reduced rate of AD, respectively. Results of the curve linear Poisson regression model showed the point of lowest risk for AD to be ∼350 mg/d with effects being similar based on apolipoprotein E gene genotype. CONCLUSIONS: Dietary choline intake ∼ 350 mg/d was associated with the lowest risk of clinical diagnosis of AD in older adults.