Higher dietary isoflavone intake is associated with lower risk of new-onset hypertension: An 18-year national cohort study.

Prior experimental studies suggest that isoflavones may reduce blood pressure, but epidemiological evidence on their association with hypertension risk remains limited and inconsistent. We hypothesized that dietary isoflavone intake is inversely associated with the risk of new-onset hypertension. This cohort study included 11,402 adults from the China Health and Nutrition Survey who were free of hypertension at baseline. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated from Cox proportional-hazards models, adjusting for potential confounders. Over 93,058 person-years, 3,993 participants (35%) developed incident hypertension. Compared with the lowest quartile, the fully adjusted HR of new-onset hypertension was lowest in the third quartile of total isoflavone intake (HR, 0.73; 95% CI: 0.65, 0.81). For the subtypes, the lowest risk was observed in the second quartile, with fully adjusted HRs of 0.74 (95% CI: 0.69, 0.83) for genistein, 0.76 (95% CI: 0.68, 0.84) for daidzein, and 0.80 (95% CI: 0.72, 0.90) for glycitein. A J-shaped relationship was observed for total isoflavones (Pnon-linearity < .001), with the lowest risk at an intake of 25.14 mg/d. Similar nonlinear associations were found for genistein, daidzein, and glycitein. Moreover, higher sodium intake weakened this negative association. This study found an inverse and J-shaped association of dietary total isoflavones and their subtypes (daidzein, genistein, and glycitein) with new-onset hypertension. These findings indicate that moderate dietary intake of isoflavones may help prevent hypertension.