Is dietary choline intake related to dementia and Alzheimer's disease risk: results from the Framingham Heart Study

Abstract
Background
The positive association of choline for cognition has been reported in both animal and human studies, yet the association of choline with the risk of incident dementia or Alzheimer's disease (AD) in humans is unclear.

Objectives
Our objective was to test the hypothesis that lower (higher) dietary choline intake is associated with increased (decreased) risk of incident dementia or AD.

Design
Data from the Framingham Heart Study (FHS) Offspring Cohort Exam 5 to Exam 9 were used. Participants were free of dementia and stroke with valid self-report 126-item Harvard food-frequency questionnaire (FFQ) at Exam 5. The intakes of total choline, its contributing compounds, and betaine were estimated based on a published nutrient database. The intakes were updated at each exam to represent the cumulative average intake across the five exams. The associations between dietary choline intake and incident dementia and AD were examined in the mixed effect Cox proportional hazard models, adjusting for covariates.

Results
A total of 3,224 participants (53.8% female, mean ± SD age 54.5 ± 9.7 year) were followed up for a mean ± SD of 16.1 ± 5.1 years (1991–2011). There were 247 incident dementia cases, of which 177 were AD. Dietary choline intake showed non-linear relationship with incident dementia and AD. After adjusting for covariates, low choline intake (defined as choline/100 ≤ 2.19 and choline/100 ≤ 2.15 in our sample) was significantly associated with incident dementia or incident AD.

Conclusion
Low choline intake was associated with increased risk of incident dementia or AD.