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Nutritional Influences on Estrogen Metabolism

Article Summary

Renata Trister DO

Estrogens affect the growth, differentiation, and function in various organs and tissues.  Although commonly known as the “female hormone”, estrogen plays an important role in bone health, protects the cardiovascular system, and influences behavior and mood. Estrogen also affects male organs such as prostate and testes. While appropriate levels of estrogens are essential for good health, excessive estrogen exposure can lead to health problems such as premenstrual syndrome (PMS), endometriosis, fibrocystic breasts and breast cancer.

Lifestyle and environmental factors can greatly influence estrogen production, metabolism, and balance. These factors include poor diet, obesity, excess alcohol consumption, high insulin levels, medications such as hormone replacement therapy and birth control pills, overexposure to chemicals found in pesticides and industrial chemicals, and agricultural hormones in animal products consumed by humans.

Nutritional Support of Optimum Estrogen Metabolism

Diet and nutrition play an important role in influencing estrogen metabolism and detoxification. Incorporating dietary changes with the addition of beneficial nutrients and herbs can profoundly affect estrogen balance.

Dietary modulation of estrogen metabolism

Consumption of cruciferous vegetables like cabbage and broccoli, and foods such as soy can significantly increase the 2-hydroxylation of estrogen. Dietary fiber intake can promote the excretion of estrogen by binding estrogens in the digestive tract and also increases sex hormone binding globulin (SHBG), thus reducing levels of free estradiol. Complex carbohydrates, such as those found in vegetables and whole grains, are more effective in optimizing estrogen metabolism than simple carbohydrates, which can raise blood glucose and insulin levels, resulting in secondary adverse influences on sex hormone balance.

Phytoestrogens — These plant compounds are similar in shape to the estrogen molecule and can bind to estrogen receptors (ERs). They are much weaker than endogenous estrogens and, through competitive inhibition, have been shown to prevent the receptor binding of “stronger”, more stimulating estrogens. Phytoestrogens are currently under extensive investigation as a potential alternative therapy for a range of conditions associated with estrogen imbalance, including menopausal symptoms, PMS, endometriosis, prevention of breast and prostate cancer, and protection against heart disease and osteoporosis.

The two main classes of phytoestrogens are isoflavones and lignans. Soy is perhaps the most common food source of isoflavones, but other excellent sources include legumes, clover, and kudzu root. Higher intakes of soy products and isoflavones, such as consumed in traditional Japanese diets, are associated with low rates of hormone-dependent cancers. Lignans are compounds found in fiber-rich foods such as flaxseeds, whole grains, legumes, and vegetables. Lignans stimulate the production of SHBG in the liver, and therefore reduce the levels of free estrogen in circulation. They also inhibit aromatase, an enzyme that synthesizes estrogen.

Vitamin E and Magnesium — Low serum vitamin E is associated with elevated estrogen levels, and may negatively affect estrogen detoxification. Women with PMS have experienced improvements of their symptoms when given supplemental vitamin E. Magnesium promotes estrogen detoxification by promoting methylation and glucuronidation, key estrogen detoxification pathways. Ovarian hormones influence magnesium levels, triggering decreases at certain times during the menstrual cycle as well as altering the calcium to magnesium ratio. These cyclical changes can produce many of the well-known symptoms of PMS in women who are deficient in magnesium and/or calcium.

Indole-3-Carbinol (I3C) – I3C is a naturally occurring compound derived from cruciferous vegetables that actively promotes the breakdown of estrogen via the beneficial 2-OH pathway. Therefore, I3C is protective to estrogen-sensitive tissues and may be beneficial to those with health issues related to excessive estrogen. Not only does I3C promote healthier estrogen metabolism, it may also act as a “weak” or anti-estrogen in a similar fashion to isoflavones.

B Vitamins — B12, B6 and folate function as important cofactors for enzymes involved in estrogen detoxification; thus, decreased levels of B vitamins can lead to increased levels of circulating estrogens. Vitamin B6 can also modulate the effects of estrogen by decreasing the cell’s response when estrogen binds to the estrogen receptor. B vitamins are also important for DNA synthesis and repair.

Beneficial Phytonutrients and Herbs

Many other compounds can promote healthy estrogen metabolism.  Curcumin, a compound found in the herb turmeric (Curcuma longa) increases the phase II detoxification of estrogens; chrysin, a bioflavonoid that inhibits aromatase activity, thus reducing the synthesis of estrogen; D-limonene from citrus fruits promotes the detoxification of estrogen and shows promise in the prevention and treatment of breast and other cancers. Antioxidants can reduce the oxidation of the 2-OH and 4-OH estrogen metabolites. Antioxidants include vitamin C, N-acetyl cysteine, selenium, and green tea.  Traditional medicines from many cultures have relied on a variety of hormone-modulating herbs in treating women’s health conditions. These include black cohosh, chaste berry, ginseng, dong quai, and licorice.