Phytoestrogens as an alternative to HRT : an investigation into the molecular effects of phytoestrogens on haemostasis in cell and animal models

Abstract

There is a direct link between the increased risk of cardiovascular disease and the menopause and this is thought to be due to the progressive lack of endogenous oestrogen in post-menopausal women. Observational studies have provided evidence that hormone therapy reduces the risk of cardiovascular disease but more recent randomised controlled clinical trials have contradicted these results. These trials have shown increases in venous thromboembolism, myocardial infarction and other coronary events in women receiving estradiol in the form of hormone therapy versus placebo. Due to these publications many women chose to use herbal remedies for relief of menopausal symptoms, many of these include phytoestrogens supplements. Phytoestrogens are a group of naturally occurring substances produced from plants with weak oestrogenic and anti-oestrogenic activity and are the main constiuents of soy. The aim of this study was to investigate the effects of physiological concentrations of soy phytoestrogens on the regulation of haemostasis gene expression and compare them to the 17β-estradiol and soy free controls. This study has shown that some of these phytoestrogens have a similar, and in some cases a greater effect, than estradiol on haemostasis gene expression, this may have implications in determining the thrombotic risk profile of women taking these supplements.