Phytoestrogens Can Decrease Ovarian Cancer Risk, According To Study
Ovarian cancer is a frequent gynecological cancer found in practice, but its causes are not well understood. There are few theories about the etiology of ovarian cancer that include: continuous ovulation, ovarian epithelium overstimulated by gonadotropins (ovulation leads to small injuries of the ovarian epithelium, that can lead to an increased and abnormal proliferation cell reaction, influenced by hormonal factors) and the inflammation theory( inflammation caused by repeated ovulation can predispose to malignant transformation). Oral contraceptives and higher number of pregnancies are considered protective factors.
Phytoestrogens have the same structure as endogenous estrogens and they are found in plants. They may exert estrogenic and antiestrogenic effects and have numerous beneficial effects as they can reduce osteoporosis risk, cardiovascular disease risk, breast cancer and menopausal symptoms. There is a vast amount of literature evaluating the impact of estrogen and phytoestrogens on breast cancer, but there is few information about the impact of phytoestrogens on ovarian cancer.
Foods relatively rich in phytoestrogens are nuts, oilseeds (flax, sesame), soy products (tofu, tempeh, soy beverages), cereals (whole wheat, barley, oats, rice) and bread, legumes (lentils , beans, sweet potatoes, carrots), fruits (apples, pomegranates), meat products, other processed foods that contain soy, vegetables, fruits, alcoholic drinks (whiskey, beer) or non-alcoholic, and medicinal herbs (fennel, anise , ginseng, hops, red clover).
One study led by Dr. Bandera E.V. evaluated the influence of dietary phytoestrogens on ovarian cancer by comparing more than 200 cases of women with ovarian cancer to more than 300 control women. Using questionnaires regarding their diet, they estimated the total amount of phytoestrogens intake, isoflavones (daidzein, genistein, formononetin, and glycitein), lignans (matairesinol, lariciresinol, pinoresinol, secoisolariciresinol) and coumestrol, both in ovarian cancer individuals and control subjects. Furthermore, the study considered other variables like: race, age, education, age of menarche, menopausal status, parity, oral contraceptive use, hormone replacement therapy (HRT) use.
Findings suggested that total phytoestrogens consumption can decrease the risk for epithelial ovarian cancer. No specific correlations were found between isoflavones, lignans, coumestrol and ovarian cancer.
The protective effect of phytoestrogens against carciogenesis may be explained by the agonist/antagonist action: they execrt an inhibition action over the enzymes that are implicated in the synthesis and the metabolism of estrogen hormones, as they can bind to estrogen receptors, especially beta receptors, implicated in cellular proliferation and differentiation and they have an inhibition action over angiogenesis in tumors.
This study was performed on a relatively small sample of subjects, and more exact results, analizing larger groups of patients are still to come.