The longitudinal association between soybean and non-soybean legumes intakes and risk of cardiovascular disease: Isfahan cohort study

Purpose The associations between legume consumption and cardiovascular events (CVEs) have extensively been studied. However, there are few studies that considered longitudinal association between legume consumption (with repeated measurements across time) and CVEs in low-income countries where legume consumption is lower than the Western countries. The authors aimed to investigate the long-term longitudinal relationship between soybean, non-soybean and overall legume consumption and CVEs using repeated measures of legumes and time-varying confounders in a cohort study of the general population. Design/methodology/approach The current study was performed within the framework of the Isfahan cohort study among 5,432 healthy participants. The participants were followed-up for fatal and non-fatal myocardial infarction, unstable angina, fatal and non-fatal stroke and sudden cardiac death for 13 years. Dietary intake was evaluated using a validated food frequency questionnaire in 2001, 2007 and 2013. The hazard ratios (HRs) and 95% confidence intervals (CI) for CVEs between categories of soybean, non-soybean and overall legumes intake were examined using marginal Cox's regression analysis. Findings Long-term consumptions of overall legumes more than three times per week and non-soybean three times or more per week compared with those who had less than once a week were associated with 19.5% (HR = 0.805, 95% CI: 0.650,0.998; p < 0.048) and a 18.5% (HR = 0.815, 95% CI: 0.673, 0.988; p < 0.037) lower risk of CVEs in the general population, respectively. However, our findings revealed no significant reduction in CVEs following a higher intake of soybeans. Originality/value In the long run, even modest consumption of legumes, but not soybeans alone, can be effective to reduce CVEs risk in a low-income population. Further studies are warranted to confirm our results in other populations, examine the associations by the type of cardiovascular events and determine any possible threshold effects in this regard.