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 Afr...