Objective To clarify the relationships between legume intake and the risk of major cardiovascular events and all-cause mortality.

Methods In this study, the data was from the Prospective Urban and Rural Epidemiology China (PURE-China) cohort study, which enrolled adults aged 35–70 years in 115 urban and rural areas in 12 provinces in China from 2005 to 2009 and followed them up every three years. The follow-up deadline for this analysis was August 10th, 2019. Legume intake was obtained through a validated food frequency questionnaire during face-to-face interviews, and was divided into four groups: ＜10.0, 10.0–＜72.4, 72.4–＜214.7, ≥214.7 g/d. The Cox frailty models were used to analyze the associations between legume intake and the risk of major cardiovascular events and all-cause mortality. Restricted cubic splines (RCS) analyses were used to examine the non-linear associations between legumes intake and the risks of major cardiovascular events and all-cause mortality.

Results A total of 41 357 subjects were included in the analysis, and the median daily intake of legumes was 72.4 (29.5, 134.3) g/d. During 11.9 (9.5, 12.6) years of median follow-up, a total of 3 175 major cardiovascular events and 1 827 all-cause deaths were recorded. Legume intake was associated with the risk of major cardiovascular events (P_non-linear ＜0.001) . In the multivariable-adjusted model, compared with individuals who consumed legumes of ＜10.0 g/d, individuals who consumed legumes of 72.4–＜214.7 g/d had a 17.0% lower risk of major cardiovascular events (HR=0.83, 95%CI 0.73–0.93, P=0.002) and 24.0% lower risk of all-cause mortality (HR=0.76, 95%CI 0.66–0.89, P=0.001). Stratified analysis showed that in the elderly population, compared with the reference population, legume intake ranging from 72.4 to ＜214.7 g/d was associated with a 34.0% reduction in the risk of major cardiovascular events (HR=0.66, 95%CI 0.50–0.86, P=0.002). Among people with hypertension, compared with the reference population, legume intake ranging from 72.4 to ＜214.7 g/d was associated with a 18.0% reduction in the risk of major cardiovascular events (HR=0.82, 95%CI 0.71–0.95, P=0.008) and a 30.0% reduction in the risk of all-cause mortality (HR=0.70, 95%CI 0.57–0.86, P=0.001). In the western region, compared with the reference population, the risk of major cardiovascular events reduced by 26.0% in the individuals with legumes intake of 72.4–＜214.7 g/d (HR=0.74, 95%CI 0.59–0.93, P=0.008). In the eastern population, compared with the reference population, the risk of all-cause mortality reduced by 29.0% in the individuals with legumes intake of 72.4–＜214.7 g/d (HR=0.71, 95%CI 0.57–0.89, P=0.002).

Conclusions There is a non-linear association between legumes intake and the risk of major cardiovascular events in the Chinese population. In the general population, elderly and hypertensive population, moderate legume intake (72.4–＜214.7 g/d) is associated with lower risks of major cardiovascular events and all-cause mortality.