Dietary phytoestrogens and plasma lipids in Dutch postmenopausal women; a cross-sectional study

Objective: Isoflavone supplementation in high doses is associated with plasma lipid, glucose and insulin levels. Little is known about the effects of intake within the range of western diets on these endpoints. Design: We conducted a population-based cross-sectional study in 301 women aged 60-75 years. Methods: Dietary isoflavone and lignan intake was assessed with a food frequency questionnaire covering habitual diet during the year preceding enrolment. The outcome measures were total cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides, Lp(a), fasting glucose and insulin levels. Data were analysed using linear regression and logistic regression models. In the analyses we adjusted for a wide range of potential confounders. Results: High intake of isoflavones was associated with lower Lp(a) levels (tertile three versus tertile one: odds ratio 0.36, 95% CI 0.16; 0.80). No relation was found between blood levels and the other plasma lipids, glucose or insulin was found. Conclusion: The results of this study suggest that an effect of dietary phytoestrogen intake at low levels on plasma lipid levels is of limited magnitude. It is premature to advise postmenopausal women with low phytoestrogen intake to change their diet towards a phytoestrogen rich diet with the sole aim to prevent cardiovascular disease.