A pilot study of phytoestrogen content of soy foods and traditional Chinese medicines for women's health in Hong Kong.

In view of the possible health benefits of phytoestrogens, a pilot study was carried out to quantitate the phytoestrogen content of soy foods and tea commonly consumed in Hong Kong, and also of traditional Chinese medicinal (TCM) products that are prescribed for menopausal symptoms and diseases relating to the menopause. Assays of daidzein and genistein were carried out using high-performance liquid chromatography, after extraction procedures. The TCM products were found to contain phytoestrogen in quantities comparable with soy products. Moreover, certain types of Chinese tea contained large quantities of phytoestrogens in the leaves, but also yielded comparable quantities in the infusion for drinking. The phytoestrogen content of these TCM may provide a scientific basis for their actions. However, clinical efficacy can only be determined by clinical trials.