Background: Adherence to a Mediterranean diet may help prevent cognitive decline in older age, but studies are limited. We examined the association of adherence to the Mediterranean diet with cognitive function and decline.
Methods: We included 6174 participants, aged 65+ years, from the cognitive substudy of the Women’s Health Study. Women provided dietary information in 1998 and completed a cognitive battery 5 years later, followed by two assessments at 2-year intervals. The primary outcomes were composite scores of global cognition and verbal memory. The alternate Mediterranean diet adherence nine-point score was constructed based on intakes of vegetables, fruits, legumes, whole grains, nuts, fish, red and processed meats, moderate alcohol, and the ratio of monounsaturated-to-saturated fats.
Results: After multivariable adjustment, the alternate Mediterranean diet score was not associated with trajectories of repeated cognitive scores (P for score quintiles medians-x-time interaction = 0.26 for global cognition and 0.40 for verbal memory), nor with overall global cognition and verbal memory at older ages, assessed by averaging the three cognitive measures (P trend = 0.63 and 0.44, respectively). Among alternate Mediterranean diet components, a higher monounsaturated-to-saturated fats ratio was associated with more favorable cognitive trajectories (P for ratio quintiles medians-x-time = 0.03 for global cognition and 0.05 for verbal memory). Greater whole grain intake was not associated with cognitive trajectories but was related to better averaged global cognition (P trend = 0.02).
Conclusions: In this large study of older women, we observed no association of the Mediterranean diet with cognitive decline. Relations between individual Mediterranean diet components, particularly whole grains, and cognitive function merit further study.
From the aDepartment of Medicine, Channing Division of Network Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA; Departments of bEpidemiology and cBiostatistics, Harvard School of Public Health, Boston, MA; dDepartment of Medicine, Division of Preventive Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA; eDepartment of Nutrition, Harvard School of Public Health, Boston, MA; and fDepartment of Psychiatry, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA.
This work was supported by research grants HL043851, CA047988, HL080467, and AG015933 from the National Institutes of Health (NIH). C.S. was supported by a Fulbright Research Scholar award and a grant from the Pôle de Recherche et d’Enseignement Supérieur (PRES) Université de Bordeaux (France). O.I.O. was supported by NIH grant K08 AG 029813.
None of the authors report any potential financial or personal conflicts of interest pertaining to this article.
Editors’ note: Related articles appear on pages 479, 500, and 503.
Correspondence: Cécilia Samieri, Channing Division of Network Medicine, 181 Longwood Avenue, Boston, MA 02115. E-mail: email@example.com.
Received October 22, 2012
Accepted January 8, 2013