Isoflavones and clinical cardiovascular risk factors in obese postmenopausal women: a randomized double-blind placebo-controlled trial.

Aims: To investigate whether 6 months of isoflavone supplementation, which has been shown to be sufficient to improve menopausal symptoms, could also improve clinical cardiovascular disease (CVD) risk factors in obese postmenopausal women, compared with a placebo.

Methods: A randomized double-blind placebo-controlled trial in which 50 obese postmenopausal women were divided into two groups (isoflavones vs. placebo) to examine the effect of 6 months of isoflavone supplement (70 mg) on clinical CVD risk factors. Body composition (DXA), medical and social characteristics, daily energy expenditure (accelerometry), dietary intake (3-day dietary record), and blood biochemical analyses (lipid profile, insulin, glucose) were obtained.

Results: At baseline, no differences were found between groups except for fasting insulin level. Women were thus considered at risk of CVD based on body composition but not biochemical variables. After 6 months, we observed that isoflavones did not favorably affect risk factors predisposing to CVD (biochemical or body composition) compared with placebo.

Conclusions: Isoflavones given for 6 months should not be considered protective against clinical CVD risk factors in obese postmenopausal women. Nevertheless, further research is needed to verify if isoflavones protect against CVD disease risk factors when administered for a longer duration or when combined with nutritional or exercise interventions. It would also be pertinent to study their effects in women with specific metabolic abnormalities.