Dietary flour supplementation decreases post-menopausal hot flushes: effect of soy and wheat.

Plants contain compounds with oestrogen--like action called phytoestrogens. Soy contains daidzin, a potent phytoestrogen, and wheat flour contains less potent enterolactones. We aimed to show in 58 postmenopausal women (age 54, range 30-70 years) with at least 14 hot flushes per week, that their daily diet supplemented with soy flour (n = 28) could reduce flushes compared with wheat flour (n = 30) over 12 weeks when randomised and double blind. Hot flushes significantly decreased in the soy and wheat flour groups (40% and 25% reduction, respectively < 0.001 for both) with a significant rapid response in the soy flour group in 6 weeks (P < 0.001) that continued. Menopausal symptom score decreased significantly in both groups (P < 0.05). Urinary daidzein excretion confirmed compliance. Vaginal cell maturation, plasma lipids and urinary calcium remained unchanged. Serum FSH decreased and urinary hydroxyproline increased in the wheat flour group.

What is the role of phytoestrogens in treating menopausal symptoms?

Most randomised placebo-controlled trials show no benefit of phytoestrogens in managing menopausal vasomotor symptoms. Concentrated phytoestrogen supplements appear to have oestrogenic actions in the breast and may interfere with the therapeutic use of tamoxifen. Unlike concentrated supplements, foods rich in phytoestrogens, such as vegetables, grains and legumes, are also excellent sources of fibre, unsaturated protein, vitamins and minerals and their consumption should be encouraged.

Phytoestrogens in health and disease.

Phytoestrogens are compounds found in a wide variety of plant foods that historically are said to exhibit estrogen-like activity and, more recently, have been reported to display both estrogenic and anti-estrogenic effects. Population-based studies have been interpreted to suggest that consumption of a phytoestrogen-rich diet is protective against breast, prostate, and bowel cancer and cardiovascular disease and ameliorates estrogen-deficiency symptoms in postmenopausal women. Consequently, there is a global movement towards increased consumption of phytoestrogen-rich foods and tabletized concentrated isoflavone extracts are being heavily promoted. Evaluating the effects and hence the potential benefits and risks of phytoestrogens is a complex task. The interindividual diversity and complexity in dietary phytoestrogen absorption and metabolism make the bioactivity of these compounds unpredictable. Epidemiological studies of relationships between phytoestrogens and cancer and cardiovascular disease that take into account confounding factors are scarce. Results of many of the in vitro and in vivo studies are conflicting and confusing. These compounds do not simply mimic the effects of human steroidal estrogen but rather demonstrate both similar and divergent actions. The ultimate actions of these compounds in specific cells are determined by many factors, including the relative levels of estrogen receptor (ER) alpha and ER beta and the diverse cocktail of co-activators and co-repressors present in any given cell type. Therefore, effects vary according to the phytoestrogen studied, cell line, tissue, species, and response being evaluated. Overall, it is naive to assume that exposure to these compounds is always good; inappropriate or excessive exposure may be detrimental. Extensive documentation of the specific intracellular effects of the various phytoestrogens in different tissues, the relationships between timing and duration of exposure and disease, and results from prospective randomized studies in humans of their clinical effects and potential side effects are essential. Only then can widespread recommendations regarding the dietary and pharmacological intake of these compounds be made.

Clinical review 92: Phytoestrogens.

We have reviewed the literature regarding the food sources, potency, population intakes, and known biological effects of phytoestrogens in humans using MEDLINE data base from the years 1975-1996. Over 600 articles pertinent to the metabolism of phytoestrogens, including female reproduction (in particular menstruation and menopause), cardiovascular disease, osteoporosis, and cancer were assessed including relevant case control or cohort studies, as well as randomized trials and review articles. Epidemiological studies regarding human data were included, as well as human cell line and animal studies when there were no relevant human data available. We conclude that phytoestrogens exhibit physiological effects in humans. Mild estrogenic changes occur in postmenopausal women. Benefits are seen regarding hypercholesterolaemia. Epidemiological, animal, and in vitro data encourage further assessment of the role of phytoestrogens in cancer prevention.

Effects of dietary phytoestrogens in postmenopausal women.

The aim of this study was to test the hypothesis that increased dietary intake of phytoestrogens reduces the health impact of the menopause. To test this hypothesis, a double-blind, randomized, entry-exit, cross-over study was conducted to assess the effects of three dietary manipulations--soy and linseed diets (high in phytoestrogens) and a wheat diet (low in phytoestrogens). Postmenopausal women were recruited and randomly assigned to one of the three dietary regimens. Urinary phytoestrogen concentrations, hot flush rate, vaginal smears, bone mineral density and bone mineral content were assessed for two 12-week periods. Comparative analysis showed no significant differences, but, when analyzed separately, groups consuming high phytoestrogen diets had between 10 and 30 times higher urinary excretion of phytoestrogens compared to those consuming the low phytoestrogen diet (p < 0.01). Study participants consuming soy, linseed and wheat diets had a 22% (not significant, n.s.), 41% (p < 0.009) and 51% (p < 0.001) reduction in hot flush rate; a 103% (p < 0.04), 5.5% (n.s.) and 11% (n.s.) increase in vaginal cytology maturation index; and a 5.2% (p < 0.04), 5.2% (n.s.) and 3.8% (n.s.) increase in bone mineral content, respectively. No changes were detected in bone mineral density. The differential effects of high phytoestrogen dietary manipulations on outcomes may represent tissue-specific responses to isoflavones and lignans contained in soy and linseed, respectively. Whilst health outcome measures were not significantly different between groups, the data obtained from separate analysis suggest that phytoestrogens in soy and linseed may be of use in ameliorating some of the symptoms of menopause. Furthermore, the significant decrease in hot flush rate in the wheat group cannot be attributable to phytoestrogens measured in this study. Due to subject variability, larger studies are still needed to evaluate population benefit.

A comparative study of safety and efficacy of continuous low dose oestradiol released from a vaginal ring compared with conjugated equine oestrogen vaginal cream in the treatment of postmenopausal urogenital atrophy.

OBJECTIVE: To compare the safety, efficacy and acceptability of a continuous low dose oestradiol releasing vaginal ring with conjugated equine oestrogen vaginal cream in the treatment of postmenopausal urogenital atrophy. DESIGN: An open, parallel, comparative multicentre trial. SETTING: Sydney and Melbourne, Australia. PARTICIPANTS AND INTERVENTIONS: One hundred and ninety-four postmenopausal women with symptoms and signs of urogenital atrophy were randomised on a 2:1 basis to 12 weeks of treatment with an oestrogen vaginal ring versus an oestrogen cream. MAIN OUTCOME MEASURES AND RESULTS: Equivalence (95% CI) was demonstrated between the two treatments for relief of vaginal dryness and dyspareunia, resolution of atrophic signs, improvement in vaginal mucosal maturation indices and reduction in vaginal pH. No significant difference was demonstrated in endometrial response to a progestogen challenge test and equivalence was demonstrated in the incidence of intercurrent bleeding episodes. The vaginal ring was significantly more acceptable than the cream P < 0.0001), and was preferred to the cream (P < 0.001). CONCLUSION: With equivalent efficacy and safety and superior acceptability to vaginal cream, the low dose oestradiol vaginal ring is an advance in vaginal delivery systems for the treatment of urogenital atrophy.

Dietary flour supplementation decreases post-menopausal hot flushes: effect of soy and wheat.

Plants contain compounds with oestrogen-like action called phytoestrogens. Soy contains daidzin, a potent phytoestrogen, and wheat flour contains less potent enterolactones. We aimed to show in 58 postmenopausal women (age 54, range 30-70 years) with at least 14 hot flushes per week, that their daily diet supplemented with soy flour (n = 28) could reduce flushes compared with wheat flour (n = 30) over 12 weeks when randomised and double blind. Hot flushes significantly decreased in the soy and wheat flour groups (40% and 25% reduction, respectively < 0.001 for both) with a significant rapid response in the soy flour group in 6 weeks (P < 0.001) that continued. Menopausal symptom score decreased significantly in both groups (P < 0.05). Urinary daidzein excretion confirmed compliance. Vaginal cell maturation, plasma lipids and urinary calcium remained unchanged. Serum FSH decreased and urinary hydroxyproline increased in the wheat flour group.

Common problems with hormone replacement therapy.

The management of the perimenopausal or menopausal woman should include providing facts about the treatment, allaying her fears and gaining some idea of her attitude to hormone therapy. These factors, plus individual treatment, result in improved patient compliance and successful management.