Phyto-estrogens are naturally-occurring plant-derived compounds (phyto-chemicals) that mimic the female hormone,estrogen. Though the estrogen activity of phyto-estrogens is low (0.25 per cent activity of estrogen),several health benefits have been attributed to phyto-estrogens including protection from cancer,osteoporosis and relief from symptoms of menopause.
Phyto-estrogens are found in a variety of medicinal herbs and foods including fennel (saunf),licorice (mulathi),dong quai (angelica),black cohosh,soy foods,legumes,chick-peas (channa),moong beans,kidney beans (rajma) and flax seeds.
Recently,phyto-estrogens have attracted attention for their potential anti-cancer activity. Several studies show that phyto-estrogens can inhibit a wide range of both hormone-dependent and hormone-independent cancer cells. Population-based studies show that the mortality due to breast,ovarian,prostate,and colon cancers has a negative correlation with phyto-estrogens in diet. High levels of phyto-estrogens were found in the blood and urine of Japanese women consuming traditional vegetarian diets and it was observed that there is low incidence of breast,endometrial and ovarian cancers in these groups. It has been observed that the incidence of prostate cancer is low in East Asian countries where the intake of phyto-estrogens is high,suggesting that dietary phyto-estrogens may play a protective role in the prevention of prostate cancer.
Lower cardiovascular disease risk has been noticed in the non-Western population possibly because of a phyto-estrogen-rich diet. Phyto-estrogens are known to exert their protective effect by their inhibition of the coagulation process and antioxidant activity that lowers LDL (bad) cholesterol levels and increases HDL (good ) cholesterol levels.
Phyto-estrogens may lower the risk of osteoporosis (bone thinning),particularly in post-menopausal women. It has been observed that osteoporosis and risk of fractures is low in post-menopausal Japanese women than in their Western counterparts. Due to increased risk of certain types of cancers or contraindications in HRT (hormone replacement therapy),phyto-estrogens may act as natural alternatives to HRT. These effects could be exerted due to improvement in bone-formation activity,anti-oxidant activity and reduction in calcium excretion.
Evidence is emerging that dietary phyto-estrogens play a beneficial role in obesity and diabetes. Ingestion of soy protein associated with isoflavones (phyto-estrogens of soybean) and flaxseed rich in lignans (phyto-estrogens of flaxseeds) improve glucose control and insulin resistance as well as reduce body weight,cholesterol and insulin levels.
Phyto-estrogens offer other promising uses. These include their role in the treatment of alcohol abuse,preservation of mental health and dementia in postmenopausal women and relief in pre-menstrual symptoms including hot flushes.
Though science hasnt yet determined the amount of phyto-estrogens we need or how exactly phyto-estrogens interact with other hormones or their general safety and the safety of isoflavone supplements,yet the benefits of phyto-estrogens in their natural form can be enjoyed and they are abundant in commonly consumed foods.