Abstract
Background/Objective: Plant-based diets are gaining global attention for their positive impact on health and sustainability; however, the nutritional value and health effects differ across plant food categories. We investigated the association of three plant-based diet indices and incident cardiovascular disease (CVD) and its subtypes. Methods: This study consisted of 10,030 Korean adults aged 40-69 years from the Korean Genome and Epidemiology Study (KoGES) in Ansan and Ansung. Using a validated food frequency questionnaire from the community-based cohorts of the KoGES, we derived three dietary indices based on food intake: (1) Overall Plant-Based Diet Index (PDI), (2) Healthful Plant-Based Diet Index (hPDI), and (3) Unhealthful Plant-Based Diet Index (uPDI). We analyzed the association between three plant-based diet indices and the incidence of CVD using a multivariate Cox proportional hazards regression model, adjusted for demographic and other CVD risk factors. Results: During 99,751 person-years, 597 CVD cases occurred. None of the three plant-based diet indices (PDI, hPDI, uPDI) were significantly associated with overall risk of CVD. When stratifying results by types of CVD, individuals with the highest adherence to uPDI had a higher risk of coronary heart disease (CHD), compared to the lowest group [HR (95% CI) = 1.62 (1.12-2.33), p-trend = 0.008], but not stroke [HR (95% CI) = 0.97 (0.66-1.42), p-trend = 0.964]. There were no associations between adherence to PDI and hPDI and the incidence of CHD and stroke. Conclusions: In this prospective cohort of Korean adults, none of the three plant-based diet indices were associated with CVD risk, whereas higher adherence to an unhealthful plant-based diet was associated with increased risk of CHD, but not stroke. These findings highlight the importance of plant food quality in CHD prevention and warrant confirmation in other populations.