Phytoestrogens as Pharma Foods.
The main food sources rich in phytoestrogens are nuts and oilseeds, followed by soy products, cereals and breads, legumes, meat products and other processed foods that may contain soy, vegetables, fruits, alcoholic and nonalcoholic beverages. Flax seed and other oilseeds contained the highest total phytoestrogen content, followed by soybeans and tofu.
The major groups of phytoestrogens include flavones, isoflavones, coumestans and lignans. The former three chemically are flavonoids. Phytoestrogens in particular isoflavones are found in high amounts in soybean and their products like tofu whereas lignans are mainly found in flax seed.
Due to the molecular similarities with estrogens, phytoestrogens mildly mimic and sometimes act as antagonists of estrogen. Studies have proved that phytoestrogens play an important role in the regulation of cholesterol and the maintenance of proper bone density post-menopause. Evidence is accruing that phytoestrogens may have protective action against diverse health disorders. They also stimulate the production of sex hormone–binding globulin (SHBG) by the liver. Higher SHBG levels result in more bound and thus less free estradiol.
Most of the research regarding flaxseed and breast cancer focuses on the lignans found in flaxseeds, and their potential for weak estrogenic or anti-estrogenic effects in a woman’s body. The evidence for a protective role of phytoestrogens is not conclusive enough for a general recommendation for
their use as dietary supplements, but phytoestrogens can be considered for therapeutic use in prostate cancer patients under certain circumstances.
Adv Food Technol Nutr Sci Open J. 2016; 2(1): 19-31. doi: 10.17140/AFTNSOJ-2-127
