Objective: To investigate the effects of low levels of intake of phytoestrogens in Western habitual diet on vascular function.
Design: A cross-sectional study.
Setting: A population-based study.
Participants: A total of 301 postmenopausal women aged 60-75 years living in The Netherlands. DETERMINANT: Dietary phytoestrogen intake as assessed using a food frequency questionnaire covering the year prior to enrollment.
Main outcome measures: Blood pressure, hypertension, endothelial function and ankle brachial index.
Results: The median isoflavone intake was 0.2 mg in the lowest tertile and 11.4 mg in the highest tertile. Median lignan intake was 0.8 and 2.2 mg, respectively. No associations were found for higher intake of isoflavones, systolic and diastolic blood pressures, ankle-arm blood pressure index, endothelial function or hypertension. For lignans no association was found for ankle-arm blood pressure index or endothelial function, but we did observe lower systolic and diastolic blood pressures and a lower prevalence of hypertension (systolic blood pressure difference T3-T1, -11.2 mmHg, 95% confidence interval = -17.8 to -4.5, P for trend = 0.001; diastolic blood pressure difference T3-T1, -3.6 mmHg, 95% confidence interval = -7.8 to 0.6, P for trend = 0,08; and prevalence of hypertension, odds ratio T3 versus T1 = 0.41, 95% confidence interval = 0.22-0.76, P for trend over tertiles = 0.004).
Conclusion: The results of this study suggest a protective effect of dietary lignan intake on blood pressure and hypertension, even at low levels.