Background: Data on the association between dietary patterns and age-related cognitive decline are inconsistent.

Objective: To determine whether dietary patterns assessed by the alternate Mediterranean diet score (aMED), the Healthy Eating Index-2010 (HEI-2010), the Alternate Healthy Eating Index 2010 (AHEI-2010), or the Dietary Approach to Stop Hypertension (DASH) diet score are associated with cognitive decline in older women, and to examine whether dietary patterns modify the risk for cognitive decline in women with hypertension.

Design: Prospective, longitudinal cohort study. Food frequency questionnaires were used to derive dietary patterns at baseline. Hypertension was defined as self-report of current drug therapy for hypertension or clinic measurement of systolic blood pressure ≥140 mm Hg or diastolic blood pressure ≥90 mm Hg.

Participants and setting: Postmenopausal women (N=6,425) aged 65 to 79 years who participated in the Women's Health Initiative Memory Study and were cognitively intact at baseline.

Main outcome measures: Cognitive decline was defined as cases of mild cognitive impairment (MCI) or probable dementia (PD). Cases were identified through rigorous screening and expert adjudication.

Statistical analyses performed: Cox proportional hazards models with multivariable adjustment were used to estimate the relative risk for developing MCI or PD.

Results: During a median follow-up of 9.11 years, we documented 499 cases of MCI and 390 of PD. In multivariable analyses we did not detect any statistically significant relationships across quintiles of aMED, HEI-2010, DASH, and AHEI-2010 scores and MCI or PD (P values for trend=0.30, 0.44, 0.23, and 0.45). In women with hypertension, we found no significant association between dietary patterns and cognitive decline (P values for trend=0.19, 0.08, 0.07, and 0.60).

Conclusions: Dietary patterns characterized by the aMED, HEI-2010, AHEI-2010, or DASH dietary score were not associated with cognitive decline in older women. Adherence to a healthy dietary pattern did not modify the risk for cognitive decline in women with hypertension.