The effect of soy protein with or without isoflavones relative to milk protein on plasma lipids in hypercholesterolemic postmenopausal women. Isoflavones and clinical cardiovascular risk factors in obese postmenopausal women: a randomized double-blind placebo-controlled trial. The effect of red clover isoflavones on menopausal symptoms, lipids and vaginal cytology in menopausal women: a randomized, double-blind, placebo-controlled study. Benefits of soy isoflavone therapeutic regimen on menopausal symptoms.
Clinical trial data and the results of a meta-analysis suggest a hypocholesterolemic effect of soy protein. The effect may be partially attributable to the isoflavones in soy. Few studies have examined the separate effects of soy protein and isoflavones.
                The objective of this study was to determine the effect of soy protein and isoflavones on plasma lipid concentrations in postmenopausal, moderately hypercholesterolemic women.
                This was a randomized, double-blind, placebo-controlled clinical trial with 3 treatment groups. After a 4-wk run-in phase during which the women consumed a milk protein supplement, the subjects were randomly assigned to 12 wk of dietary protein supplementation (42 g/d) with either a milk protein (Milk group) or 1 of 2 soy proteins containing either trace amounts of isoflavones (Soy- group) or 80 mg aglycone isoflavones (Soy+ group).
                LDL-cholesterol concentrations decreased more in the Soy+ group (n = 31) than in the Soy- group (n = 33) (0.38 compared with 0.09 mmol/L; P = 0.005), but neither of these changes was significantly different from the 0.26-mmol/L decrease observed in the Milk group (n = 30). The results for total cholesterol were similar to those for LDL cholesterol. There were no significant differences in HDL-cholesterol or triacylglycerol concentrations between the 3 groups.
                The difference in total- and LDL-cholesterol lowering between the 2 soy-protein supplements suggests an effect attributable to the isoflavone-containing fraction. However, the unexpected LDL-cholesterol lowering observed in the Milk group, and the fact that there was no significant difference between either soy group and the Milk group, suggests that changes may have been due to other factors related to participation in the study. 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.
                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.
                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.
                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. Background: The unexpected results of the Women's Health Initiative study have decreased the use of conventional hormone therapy (HT), changing physicians' and patients' attitudes towards HT and increasing their interest in alternative options.
                The present study aimed to evaluate the effect of isoflavones contained in red clover extracts (Trifolium pratense) on menopausal symptoms, lipids and vaginal cytology in menopausal women.
                Sixty postmenopausal women aged >40 years, non-users of HT, with Kupperman index score 15, were double-blindly randomized to receive either a commercially available red clover isoflavone supplement (80 mg/day) or placebo for 90 days. Subsequently, after a 7-day washout period, subjects switched to receive the opposite treatment for a further 90 days. Kupperman index score was determined and fasting blood and vaginal cytologic sampling performed at baseline, 90 and 180 days.
                Fifty-three women (88.3%) completed the trial. Mean age was 51.3 +/- 3.5 years, 69.7% of the women were aged 50 years or more. There was no significant effect on body mass index, weight or blood pressure after either treatment phase. Baseline Kupperman index score decreased significantly after each treatment phase, with the decrease more pronounced after the isoflavone phase (baseline: 27.2 +/- 7.7; after isoflavone: 5.9 +/- 3.9; after placebo: 20.9 +/- 5.3, p < 0.05). Red clover isoflavone supplementation significantly decreased the rate of menopausal symptoms and had a positive effect on vaginal cytology as expressed by improvement in karyopyknotic, cornification and basal cell maturation indices. Mean total cholesterol, low-density lipoprotein-cholesterol and triglyceride levels also decreased; however, only the latter was significantly lower compared with placebo.
                Compared with placebo, red clover isoflavone supplementation in postmenopausal women significantly decreased menopausal symptoms and had a positive effect on vaginal cytology and triglyceride levels. To examine the change in menopausal symptoms and cardiovascular risk factors in response to 4 months of daily 100-mg soy isoflavone in postmenopausal women.
                In this double-blind, placebo-controlled study, 80 women were randomly assigned to isoflavone (n = 40) and placebo (n = 40) treatment. The menopausal Kupperman index was used to assess change in menopausal symptoms at baseline and after 4 months of treatment. Cardiovascular risk factors were assessed by evaluating plasma lipid levels, body mass index, blood pressure, and glucose levels in the participants. To examine the effects of this regime on endogenous hormone levels, follicle-stimulating hormone (FSH), luteinizing hormone (LH), and 17 beta-estradiol were measured. Transvaginal sonography was performed to quantify endometrial thickness.
                The data showed a decrease in menopausal symptoms (P <.01, paired t test, two-tailed, between baseline and isoflavone groups, and P <.01, unpaired t test, between placebo and isoflavone groups). Total cholesterol and low-density lipoprotein decreased significantly in the isoflavone group compared with the baseline or placebo group (P <.001, paired t test, two-tailed, between baseline and isoflavone groups, and P <.01, unpaired t test, between placebo and isoflavone groups). The isoflavone treatment appeared to have no effect on blood pressure, plasma glucose, and high-density lipoprotein and triglyceride levels.
                This study suggests that isoflavone 100-mg regime treatment may be a safe and effective alternative therapy for menopausal symptoms and may offer a benefit to the cardiovascular system.
We found no evidence for effects of isoflavones on patient-important outcomes or lowering of cholesterol levels in people with hypercholesterolaemia. Our findings have to be interpreted with caution due to high or unclear risk of bias in several risk of bias domains, and low number of participants in trials.