Objectives: We examined whether accordance to the DASH (Dietary Approach to Stop Hypertension) and Mediterranean diets is associated with slower cognitive decline in a prospective Chicago cohort study of older persons, the Memory and Aging Project.
Methods: The sample comprised 826 Memory and Aging Project participants (aged 81.5 ± 7.1 years) who completed a 144-item food frequency questionnaire at baseline and 2 or more cognitive assessments over 4.1 years. Dietary scores were computed for accordance to the DASH diet (0-10) and the Mediterranean diet (MedDietScore) (0-55). For both, higher scores reflect greater accordance. Both patterns share at least 3 common food components. Cognitive function was assessed annually with 19 cognitive tests from which global cognitive scores and summary measures are computed.
Results: The mean global cognitive score at baseline was 0.12 (range, -3.23 to 1.60) with an overall mean annual change in score of -0.08 standardized units. Only 13 participants had possible dementia. The mean DASH score was 4.1 (range, 1.0-8.5) and the MedDietScore was 31.3 (range, 18-46). In mixed models adjusted for covariates, a 1-unit difference in DASH score was associated with a slower rate of global cognitive decline by 0.007 standardized units (standard error of estimate = 0.003, p = 0.03). Similarly, a 1-unit-higher MedDietScore was associated with a slower rate of global cognitive decline by 0.002 standardized units (standard error of estimate = 0.001, p = 0.01).
Conclusions: These findings support the hypothesis that both the DASH and Mediterranean diet patterns are associated with slower rates of cognitive decline in the same cohort of older persons.
© 2014 American Academy of Neurology.