Abstract
OBJECTIVE: Isoflavones, a group of soybean nutrients, have been found to provide a wide range of benefits to the human body. The prospective cohort study aims to examine the association of dietary intake of isoflavones with all-cause mortality and heart disease mortality in the US. MATERIALS AND METHODS: In this study, We conducted to explore the potential correlation of isoflavones (total isoflavones, genistein, and daidzein) intake with the risk of all-cause mortality and heart disease mortality. The mortality status and the heart disease cause of death were determined by NHANES-linked National Death Index public access files through December 31, 2019. The association of dietary isoflavones intake with all-cause mortality and heart disease mortality was analyzed by multivariate Cox regression model to compute hazard ratio (HR) and 95% confidence interval (CI), with adjustment for some demographic characteristics, lifestyle factors, and comorbidities. In addition, we employed Kaplan-Meier curves, subgroups and restricted cubic spline models to assess the effect of dietary isoflavones in different circumstances. RESULT: The final study population was 11,979 participants, with 1423 participants determined as deceased (7.95%). After adjusting for multiple variables, the study identified an inverse relationship between total isoflavones [Hazard Ratio (HR) 0.85, 95% CI: 0.74-0.99], genistein [HR 0.82, 95% CI: 0.69-0.98], daidzein [HR 0.81, 95% CI: 0.70-0.94] and the incidence of all-cause mortality. Similarly, only high levels of intake daidzein [HR 0.73, 95% CI: 0.53-0.99] were no significantly associated with heart disease mortality. Additionally, a non-linear relationship was observed between dietary isoflavones and all-cause mortality in female participants (p-value for nonlinear < 0.05 and p-value for overall < 0.05). CONCLUSION: Our findings suggest dietary intake of total isoflavones, genistein, and daidzein in the right amounts was associated with lower all-cause mortality and exhibited an association of results for mortality from heart disease with daidzein to diminish the chances of heart disease mortality. The present study reveals a U-shaped association between dietary isoflavones and all-cause mortality in female participants.