Association of soy food with cardiovascular outcomes and all-cause mortality in a Chinese population: a nationwide prospective cohort study.

PURPOSE: This study aimed to clarify the association of soy intake with cardiovascular disease (CVD) and all-cause mortality. METHODS: We conducted a prospective cohort study in a Chinese population composed of 97,930 participants aged ≥ 40 years old without CVD at baseline in 2011. Habitual soy intake over a period of 12 months was evaluated using a food frequency questionnaire. All participants were classified into four groups based on their soy food consumption levels: < 15, 15-29, 30-59, and ≥ 60 g/day, with the lowest category as the reference group. Follow-up was conducted between 2014 and 2016 to assess CVD incidence and all-cause mortality since baseline, which was collected from the local mortality and disease registers of the National Disease Surveillance Point System and National Health Insurance System. The Cox proportional hazards regression models were used to analyze the relationship of soy intake with later CVD events and all-cause mortality. RESULTS: During 350,604 person-years of follow-up (median [interquartile range]: 3.16 [2.98, 4.77] years), 2523 total CVD events and 1473 all-cause mortalities were documented. After controlling for covariates, the hazard ratios (95% confidence intervals) for total CVD events across increasing soy intake levels were 1.03 (0.93-1.14); 0.96 (0.86-1.07); and 0.86 (0.75-0.98; p for trend = 0.0434), while those for all-cause mortality were 0.88 (0.77-1.02); 0.86 (0.74-1.00); and 0.83 (0.69-0.99; p for trend = 0.0084). CONCLUSION: High soy intake was associated with a reduced risk of total CVD events and all-cause mortality among a Chinese population.