Dietary intake of phytoestrogens is associated with a favorable metabolic cardiovascular risk profile in postmenopausal US women: The Framingham Study

Hypertension, central obesity and dyslipidemia are associated with high cardiovascular risk. Estrogen therapy in women has beneficial effects on some of these metabolic cardiovascular risk factors. It is not known whether dietary estrogens have similar effects, especially in Western populations. We studied the association between dietary phytoestrogen intake and metabolic cardiovascular risk factors in postmenopausal women. For this purpose, 939 postmenopausal women participating in the Framingham Offspring Study were included in this cross-sectional study. Mean blood pressure, waist-hip ratio (WHR) and lipoprotein levels were determined in quartile categories of dietary phytoestrogen (isoflavones and lignans) intake, determined by a food-frequency questionnaire. In addition, a metabolic syndrome score was defined according to WHO criteria (range 0-6). The WHR was lower in women in the highest quartile of intake of lignans compared with the lowest [-0.017; 95% confidence interval (CI) -0.030 to -0.0016]. In the highest quartile of intake of isoflavones, plasma triglyceride levels were 0.16 mmol/L lower (95% Cl, -0.30 to -0.02) compared with the lowest quartile of isoflavones; for lignan intake, this difference was 0.23 mmol/L (95% Cl, -0.37 to -0.09). In the highest quartile of isoflavone intake, the mean cardiovascular risk factor metabolic score was 0.43 points lower (95% Cl, -0.70 to -0.16) than the lowest quartile. The difference in this score between the extreme quartiles of intake of lignans was -0.55 points (95% Cl, -0.82 to -0.28). In conclusion, high intake of phytoestrogens in postmenopausal women appears to be associated with a favorable metabolic cardiovascular risk profile.