Effects of phytoestrogens

There are no conclusive findings in the literature indicating the effects of phytoestrogens on the endometrium in women. Also, there are inconclusive opinions regarding their effects on ovarian or gastrointestinal cancers. However, most studies suggest a beneficial effect of plant-derived oestrogens in the prevention of these cancers.

It has also been shown that women consuming soy products had a 9.3 % reduction in blood cholesterol, a 12.9 % reduction in LDL fraction and a 10.5 % reduction in triglycerides, but no change in HDL fraction. In the USA, the Food and Drug Administration recommends the consumption of a diet rich in phytoestrogens as a factor in reducing the risk of coronary heart disease and atherosclerosis.

Data on the effects of phytoestrogen intake on bone tissue are very scarce. Phytoestrogens can increase bone density and reduce the incidence of osteoporotic fractures. Bone mineral density and mechanical strength have also been shown to be higher in women in Mediterranean countries and whose diets contain high levels of phytoestrogens. A study among postmenopausal women who consumed 60 mg of soy protein per day showed remineralisation and an increase in bone mineral density after six months of diet, and similar results were obtained in women who used soy-enriched bread in their diet. However, despite all the promising results regarding the effect of plant-derived oestrogens on bone tissue in postmenopausal women, when using only phytoestrogens without classical HRT, bone mineral density should be assessed every 2-3 years.

The North American Menopausal Society stated that 50 mg of isoflavones should be consumed daily for blood cholesterol reduction, 40-80 mg for protective effects on blood vessels, 50 mg for beneficial effects on bones, and 40-80 mg for relief of prolapse symptoms. An opinion from the North American Menopausal Society confirms that there are significant health benefits from consuming soy and its products. But in fact, there are still many conflicting research results in the literature and little convincing evidence for such multifaceted beneficial effects of isoflavones. This is most likely due to the heterogeneity of the material studied; the consumption of not only soya, but also its fermented and unfermented products, or a diet only enriched with isoflavones. It seems that additional large-scale clinical trials should be conducted to definitively determine their usefulness in the treatment of menopausal symptoms as an alternative monotherapy or as an adjunct to treatment with classical hormone replacement therapy.

For women who do not wish to take oestrogen, the consumption of foods rich in isoflavones and their preparations can bring many benefits, but it seems that this cannot be the only therapy for patients who require oestrogen therapy.