Abstract 066: A Healthy Plant-based Diet Was Associated With Slower Cognitive Decline In African Americans: A Biracial Community-based Cohort Of Older Adults

Abstract

Background: African Americans (AAs) are about twice as likely to develop dementia compared to non-Hispanic whites (NHWs). Dietary modification is an effective preventive strategy to reduce the rate of cognitive decline, a hallmark feature of dementia; however, evidence from diverse populations focusing on AAs is minimal. Objective: To evaluate the association between a plant-based diet and the rate of cognitive decline in a population-based sample of AAs and NHWs. Method: This study consisted of 4753 participants (62% African American, 63% female) in a biracial population-based study in the United States (Chicago Health and Aging Project, 1993 to 2012). Plant-based diet quality was evaluated by the overall plant-based diet index (PDI), the healthful PDI (hPDI), and the unhealthful PDI (uPDI). Global cognition was assessed using a composite score of four tests of cognition. We used mixed models to examine the association between PDI, hPDI, and uPDI with the rate of decline in global cognition, perceptual speed, and episodic memory. Models were adjusted for age, sex, apoE genotype, education, cognitive activities, smoking status, calorie intake, risk factors of cardiovascular disease, time, and an interaction term of time with each covariate. Results: We demonstrated that there were distinct differences in the association of dietary patterns with cognitive decline in AAs and NHWs. AAs had higher intakes of egg, fish or seafood, sugar-sweetened beverages, and whole grains compared to NHWs (p<0.001 for all). Higher hPDI was associated with a slower rate of decline in global cognition, perceptual speed, and episodic memory in AAs but not NHWs. AAs in the highest quintile of hPDI had significantly slower rates of decline in global cognition, β = 0.0183 (p=0.032), perceptual speed β = 0.0179 (p=0.04), and episodic memory β=0.0183 (p=0.04) compared to individuals in the lowest quintile of hPDI. The rate of global cognitive decline in the highest quintile was slowed by 28.4% when compared to individuals in the lowest quintile of hPDI in AAs. There were no associations with either PDI or uPDI and the rate of cognitive decline in either racial group. Conclusion: AAs and NHWs have distinct dietary patterns. A healthy plant-based diet was associated with a slower rate of decline in global cognition, perceptual speed, and episodic memory in AAs. These results are informative in facilitating the development of tailored dietary recommendations for the prevention of cognitive decline in diverse populations.