Estrogen is a hormone present in humans. It can be naturally supplemented through dietary choices. Many plant-based foods contain natural estrogen called phytoestrogens. The two main types of phytoestrogens are lignans and flavonoids. Lignans are phytoestrogens themselves. Flavonoids, such as isoflavones, flavones and coumestans, are polyphenals commonly found in fruits and vegetables. There are thousands of different polyphenals, and many of them contain phytoestrogens. The highest quantities of phytoestrogens are in found in flaxseed and in soy beans and soy bean products. However, several other foods are significant sources of phytoestrogens.
Flaxseed contains lignans and provides the highest concentrations of phytoestrogens. According to a chart provided on the Dietry Fiber Food site, flaxseed contains approximately 379,380 micrograms of phytoestrogens per 100 grams. Flaxseed also contains soluble fiber, which helps the body to process phytoestrogens. The phytoestrogens in flaxseed are present in its whole-seed, ground-meal or powder forms. Flaxseed oil lacks both the fiber and much of the lignans present in the other forms.
Soy Beans and Soy Bean Products
Soy beans and soy bean products, such as tofu and soy yogurt, are rich in flavonoids and contain the second-highest levels of phytoestrogens. Soy beans provide approximately 103,920 micrograms of phytoestrogens per 100 grams; tofu provides approximately 27,150 micrograms per 100 grams and soy yogurt provides approximately 10,275 micrograms per 100 grams. Because of the serving proportions compared to the quantity of phytoestrogens present, soy beans and tofu may be an easier way to consume high levels of phytoestrogens.
Other Food Sources
While flaxseed and soy beans are the richest sources of phytoestrogens, there are several other foods that provide significant quantities of phytoestrogens. Seeds, nuts, grains, legumes and sprouts are generally good sources of phytoestrogens. Sesame seeds, for instance, provide approximately 8,008 micrograms of phytoestrogens per 100 grams. Multigrain breads contain 4,798 micrograms per 100 grams; hummus, at 993 micrograms per 100 grams and garlic at 603 micrograms per 100 grams, are other sources of relatively high levels of phytoestrogens. Many fruits and vegetables, such as blueberries and onions also contain phytoestrogens, though in lesser amounts. Even coffee and milk provide small quantities of phytoestrogens, six micrograms and one microgram per 100 grams, respectively.
Phytoestrogen supplements are also available at many health food stores and pharmacies.