Midlife healthy-diet index and late-life dementia and Alzheimer's disease.

Aim: To study long-term effects of dietary patterns on dementia and Alzheimer's disease (AD).

Methods: Of 525 subjects randomly selected from population-based cohorts surveyed at midlife, a total of 385 (73%) subjects were re-examined 14 years later in the CAIDE study. A healthy-diet index (range 0-17) was constructed including both healthy and unhealthy dietary components.

Results: Persons with a healthy diet (healthy-diet index >8 points) had a decreased risk of dementia (OR 0.12, 95% CI 0.02-0.85) and AD (OR 0.08, 95% CI 0.01-0.89) compared with persons with an unhealthy diet (0-8 points), adjusting for several possible confounders.

Conclusions: Healthy diet at midlife is associated with a decreased risk of dementia/AD in late life. These findings highlight the importance of dietary patterns and may make more effective measures for dementia/AD prevention or postponement possible.