The Inverse Association Between Isoflavone Intake and Prevalence of Metabolic Syndrome: A Cross-Sectional Study from National Health and Nutrition Examination Survey

Objective: Metabolic syndrome (MetS) is a global disease burden that has resulted in 10 million people being affected by it, yet no new drugs have been approved for clinical treatment. Isoflavone may be able to stop the development of MetS or enhance its treatment. Therefore, we investigated the relationship between dietary intake of isoflavone and prevalence of MetS to find potentially effective treatments. Methods: We conducted a cross-sectional study using data from 8512 National Health and Nutrition Examination Survey (NHANES) participants from 2007 to 2010 and 2017 to 2018 and their associated isoflavone intake from the flavonoid database in the USDA Food and Nutrient Database for Dietary Studies (FNDDS). We investigated the relationship between MetS status and isoflavone intake by adjusting for confounding variables using multivariable logistic regression models. Results: In a multivariable-adjusted model, there was a negative association between isoflavone intake and the incidence of MetS (odds ratio for Q4 vs. Q1 was 0.66, 95% confidence interval = 0.51-0.86, P = 0.003, p for trend was <0.001). This inverse association remained robust across most subgroups, while nonsignificant interactions were tested between isoflavone intake and age, sex, ethnicity, economic status, body mass index, smoking status, alcohol consumption, and physical activity level (P values for interaction >0.05). Conclusions: We found that MetS prevalence decreased with increased isoflavone intake, suggesting that dietary patterns of soy food or supplement consumption may be a valuable strategy to reduce the disease burden and the prevalence of MetS.