(P17-019-25) Associations Between Plant-Based Diet Indices and Cardiovascular Disease, Cancer, and All-Cause Mortality in the Cancer Prevention Study-II Nutrition Cohort

Objectives: This study evaluated associations between plant-based dietary patterns and cancer, cardiovascular disease (CVD), and all-cause mortality.

Methods: In 1999, women (n=51,869) and men (n=33,109) (mean age ± SD: 68.8 ± 6.1 yrs) from the Cancer Prevention Study (CPS)-II Nutrition Cohort completed a 152-item Food Frequency Questionnaire (FFQ) and questions on health and lifestyle. Participants were followed until 2020 for cause of death. Dietary intake (serving/d) estimated from the FFQ was used to calculate Plant-based Diet Index scores (overall [PDI], Healthful [hPDI], and Unhealthful [uPDI]). An extended multivariate Cox (non-PH) model with follow-up time of 0-10 yrs and >10 yrs was used to estimate hazard ratios (HR) and 95% CI for mortality across diet index quintiles. Covariates in all models included demographic and lifestyle characteristics (age, sex, race, education, BMI, total energy, smoking status, physical activity, margarine, NSAID/aspirin) and health status (hypertension, hypercholesterolemia, diabetes).

Results: Throughout 1,435,817 person-years, there were 46,718 total deaths (15,326 CVD; 10,365 Cancer). After ten years of follow-up, those in the highest quintile of PDI had lower risk of CVD mortality (HR=0.79, 95%CI: 0.71, 0.88) and all-cause mortality (HR=0.75, 95%CI: 0.69, 0.80) when compared to the lowest quintile. For hPDI, mortality results were similar (CVD: HR=0.76, 95%CI: 0.68, 0.85; all-cause: HR=0.82, 95%CI: 0.77, 0.89). However, mortality risk was higher for those in the highest quintile of uPDI (CVD: HR=1.23, 95%CI: 1.10, 1.37; all-cause: HR=1.22, 95%CI 1.13, 1.31). For cancer mortality, only PDI was associated with a lower risk (HR=0.83, 95%CI 0.75, 0.92). All associations were attenuated with follow-up of 10+yrs.

Conclusions: Greater dietary alignment with a healthy plant-based diet was associated with lower risk of CVD and all-cause mortality, whereas greater alignment with an unhealthy plant-based diet was associated with an increased risk for both. Alignment with an overall plant-based diet was also associated with a reduced risk of cancer mortality. Incorporating healthy plant foods into one’s dietary pattern appears to play an important role in health and reduction of mortality risk.

Funding Sources: American Cancer Society