Emily H Belarmino, Jessica Blair, Neil A Zakai, Mary Cushman, Monika M Safford, Carol R Oladele, Suzanne E Judd
In this study, greater adherence to healthy plant-based diets was associated with lower CHD risk but overall plant-based diets had heterogeneous associations with CHD incidence and mortality. Healthy plant-based diets appear to support heart health.
BACKGROUND: Plant-based diets may protect against adverse cardiovascular outcomes, but the level of protection may differ by dietary composition and individual characteristics. Black and rural Americans - two groups with high burden of cardiovascular morbidity and mortality - have had limited representation in plant-based diet research.
OBJECTIVE: This prospective cohort study examined associations between plant-based diets and stroke incidence, coronary heart disease (CHD) incidence, and CHD mortality among participants in the REasons for Geographic and Racial Differences in Stroke (REGARDS) study.
METHODS: This study included 14,776 adults. Three plant-based diet scores were calculated from food frequency questionnaires: plant-based diet-index (PDI), healthy plant-based diet index (hPDI), and unhealthy plant-based diet index (uPDI). Cox proportional hazards models estimated associations of quintiles of each plant-based diet score and cardiovascular outcomes, adjusting for sociodemographic characteristics, health risk factors, and caloric intake.
RESULTS: Between baseline (2003-2007) and 2019 there were 700 cases of incident stroke, 1047 cases of incident CHD, and 944 CHD deaths. Plant-based diets were not associated with stroke. Comparing the highest to lowest quintile, higher hPDI was associated with lower CHD incidence (HR 0.72 (0.58, 0.90), p-trend=0.03). An interaction (p=0.03) between hPDI and sex for CHD mortality revealed an inverse association between hPDI and mortality among females only. PDI was associated with lower CHD mortality (HR 0.73 (0.59, 0.90), p-trend=0.001), but higher risk of incident CHD (HR 1.60 (1.09, 2.33), p-trend=0.009). An interaction (p=0.006) was found between PDI and urban status for incident CHD with higher PDI associated with higher CHD among non-rural adults only. The uPDI was not associated with CHD incidence or mortality. Associations did not differ by race.
CONCLUSIONS: In this study, greater adherence to healthy plant-based diets was associated with lower CHD risk but overall plant-based diets had heterogeneous associations with CHD incidence and mortality. Healthy plant-based diets appear to support heart health.