Estrogen is a hormone primarily involved in the development, maturation and function of the female reproductive system. Phytoestrogens are natural estrogens found in some foods that can bind to estrogen receptors in your body, leading to either an estrogenic effect or an antiestrogenic effect. Always speak with your doctor if you are concerned about low estrogen and before making changes to your diet.
Phytoestrogens and Health
The National Institutes of Health states more research is needed on phytoestrogens -- whether they are beneficial or harmful to your health is likely a complex matter depending on your health status, age and the presence or absence of some live gut bacteria. Some possible benefits of phytoestrogens are a lowered risk of osteoporosis, breast cancer, menopausal symptoms and heart disease. On the other hand, phytoestrogens may also be considered detrimental endocrine disruptors, with the potential to disrupt lactation, puberty timing and sex specific behavior. They may also compromise fertility and manipulate hormones. Researchers of a mini review published in 2007 in "Clinical Cases in Mineral and Bone Metabolism" subdivided phytoestrogens into four major categories. The most abundant sources of phytoestrogens are isoflavones. The other three food sources of phytoestrogens are lignans, coumestans and stilbenes.
According to researchers of the 2007 mini review, isoflavone phytoestrogens are found mainly in legumes, particularly soy beans and soy-based food products. They are also found in other legumes, namely kidney beans, chickpeas, peas, lentils and peanuts. Additionally, isoflavone phytoestrogens can be found in food sources such as wheat bran, barley, red cabbage, broccoli, black and green tea and the herb red clover.
Lignans -- An Array of Food Sources
Lignans are another food source of phytoestrogens, with the highest amount found in flaxseed. Lignans are also found in whole grains, barley, cranberries, blueberries, zucchini and carrots. According to the Linus Pauling Institute, sesame seeds are the next highest in lignans after flaxseed, followed by curly kale, broccoli, apricots, cabbage, Brussels sprouts, strawberries, tofu and dark rye bread.
Clover and soybean sprouts are highest in a phytoestrogen called coumestrol, a coumestan that can bind to estrogen receptors. Brussels sprouts and spinach also contain coumestrol at a lower level, according to researchers of the 2007 mini review published in "Clinical Cases in Mineral and Bone Metabolism."
The Right Amount of Resveratrol
Resveratrol is a phytoestrogen contained in foods such as grapes, wines, red grape juice, peanuts and some berries, including blueberries, cranberries and bilberries. This compound has been studied for its possible anti-cancer properties, but its effect as a phytoestrogen requires more research. Researchers of a study published in 2014 in "Experimental and Therapeutic Medicine" found that resveratrol had an antitumor effect on pituitary tumors due to its antiestrogenic effect. This is because estrogen helps in the development and progression of prolactinoma -- a condition in which a tumor on your pituitary gland causes the overproduction of the hormone prolactin. However, more research is needed because the effect was dependent on the concentration of resveratrol and the duration of the treatment.
- Clinical Cases in Mineral and Bone Metabolism: Phytoestrogens: food or drug?
- Front Neuroendocrinology: The Pros and Cons of Phytoestrogens
- Linus Pauling Institute: Lignans
- NYU Langone Medical Center: Isoflavones
- Encyclopedia Britannica: Estrogen
- Experimental and Therapeutic Medicine: Effects of Resveratrol on Cell Growth and Prolactin Synthesis in GH3 Cells
- Linus Pauling Institute: Resveratrol
- Medline Plus: Prolactinoma