Soy isoflavone intake and risk of cardiovascular disease in adults: A systematic review and dose-response meta-analysis of prospective cohort studies

We examined the association between soy isoflavone intake and risk of cardiovascular disease (CVD) outcomes in adults. We searched the online databases for relevant studies published up to September 2021. In total, 13 publications were included in the systematic review and 12 in the meta-analysis. We found that a high intake of soy isoflavones was significantly associated with a lower risk of coronary heart disease (CHD) among whole populations (Pooled RR: 0.92, 95% CI: 0.85-0.99, I² = 41.0%, P_{heterogeneity} = 0.10) and a lower risk of overall CVD (Pooled RR: 0.91, 95% CI: 0.84-0.98, I² = 30.7%, P_{heterogeneity} = 0.19) and CHD (Pooled RR: 0.89, 95% CI: 0.83-0.96, I² = 14.4%, P_{heterogeneity} = 0.32) among Western population. In the linear dose-response analysis, a 3 mg/day increase in soy isoflavone intake was associated with 16% and 14% lower risks of overall CVD and CHD, respectively, among Western population. In conclusion, we found that soy isoflavone intake was associated with a lower risk of overall CVD and CHD in adults, particularly among Western population.