Plant-Based Dietary Patterns and Risk of Alzheimer Disease and Related Dementias in the Multiethnic Cohort Study

BACKGROUND AND OBJECTIVES: Plant-based diets have been linked to slower cognitive decline, but data on long-term dietary changes and from diverse populations are limited. The primary aim of this study was to examine plant-based dietary patterns and their change over time in relation to Alzheimer disease and related dementias (ADRDs). METHODS: This prospective longitudinal analysis of the Multiethnic Cohort Study, based in Hawaii and California (primarily Los Angeles County), included data on African American, Japanese American, Latino, Native Hawaiian, and White participants who completed food frequency questionnaires at baseline (1993-1996; age 45-75 years) and at 10-year follow-up (2003-2008) and whose Medicare claims were linked to identify incident ADRDs. A priori indices for the overall plant-based diet index (PDI), the healthful plant-based diet index (hPDI), and the unhealthful plant-based diet index (uPDI) were analyzed in Cox regression models for ADRD. RESULTS: ℇ4 carrier status. DISCUSSION: These findings suggest that adopting plant-based diets, specifically refraining from low-quality plant-based diets, even at an older age, is associated with a lower risk of ADRDs.