Plant-based diets and all-cause and cause-specific mortality among patients with cardiovascular disease: a population-based cohort study†

Abstract

The role of plant-based diets in preventing premature death among patients with cardiovascular disease (CVD) has remained unknown. We aim to explore the association of plant-based dietary patterns with all-cause and cause-specific mortality among patients with CVD. A total of 10 824 participants with CVD at the baseline were followed up in the UK Biobank. We constructed three types of plant-based diet indexes [an overall plant-based diet index (PDI), a healthful PDI (hPDI), and an unhealthful PDI (uPDI)] by assigning different weights to various food groups from web-based 24 h dietary recall questionnaires. The national death registry documented the primary causes of death. The Cox proportional hazards regression models were utilized to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for mortality. Over a median of 9.5 years follow-up, 1273 death cases were ascertained. After multivariable adjustment, PDI had an inverse correlation with all-cause mortality [HR_{T3 vs. T1}: 0.81 (0.70–0.94), P_trend = 0.005] and marginal inverse association with CVD mortality [HR_{T3 vs. T1}: 0.78 (0.61–0.99), P_trend = 0.038], while uPDI displayed a positive correlation with all-cause mortality [HR_{T3 vs. T1}: 1.33 (1.16–1.53), P_trend < 0.001], CVD, and cancer mortality. Additionally, in mediation analyses, serum concentration of C-reactive protein (CRP) accounted for 6.2%, 4.0%, and 5.1% of the relationship between uPDI and all-cause, CVD, and cancer mortality, respectively. No significant associations were detected between hPDI and mortality. Our findings support dietary guidelines that recommend limiting the consumption of unhealthy plant-based foods.