Estrogen, a steroid compound and primary female sex hormone, is found in both men and women. Too much estrogen can lead to estrogen dominance, which can contribute to medical conditions, such as breast cancer. Too little leads to a hormone imbalance, with symptoms such as hot flashes. Naturally occurring estrogen, known as phytoestrogen, is found in many foods and, according to Cornell University, falls into three main groups: isoflavones, lignans and coumestans.
Isoflavones
Isoflavones are organic compounds found in many plants. They are found in high concentration in beans from the legume family. Soybeans and soy products are the richest source of isoflavones. Red clover also contains a significant amount of isoflavones. The chemical structure of isoflavones is very similar to estrogen, which is why isoflavones are beneficial.
In individuals with too much estrogen, isoflavones can compete with estrogen by attaching to the estrogen receptors, therefore reducing the activity of the estrogen and helping decrease health risks associated with too much estrogen. For those with a low level of estrogen, such as during menopause, isoflavones can ease symptoms by binding to the receptors. The way in which phytoestrogen acts within the body, according to Cornell University, is dependent on the level of phytoestrogen; it acts like estrogen at low levels and blocks estrogen at high levels.
Lignans
Lignans, the second type of phytoestrogen, are found in seeds, fruits and vegetables. The highest concentration of lignans is found in flax seed, according to DietaryFiberFood. Sesame seeds, sunflower seeds, poppy seeds, cashews and peanuts also contain lignan.
In addition, vegetables and legumes are good sources of lignans, with curly kale and broccoli leading this group with the highest concentrations of lignans. White cabbage, red cabbage, brussels sprouts, cauliflower and sauerkraut are also good sources of phytoestrogen. Other vegetables that contain lignan include garlic, french beans, red and green sweet peppers, carrots and spinach.
The fruits with the highest concentration of lignans include apricots, strawberries, peaches, pears, nectarines, raisins, grapefruit, cherries and kiwi. Plums, black and green olives, oranges, melon and grapes are also a significant source of lignans.
Coumestans
Coumestans are the least studied of the phytoestrogen groups, but, according to the Symtoms of Menopause website, they are very similar in structure to isoflavones. Foods rich in coumestans include pinto beans, split peas, alfalfa, soybean and clover sprouts, and lima beans.
