Phyto- is from the Greek phyton meaning plant. A phytoestrogen is a naturally-occurring plant nutrient that exerts an estrogen-like action on the body. Scientists have discovered hundreds of phytoestrogens including soybeans, whole grains, seeds (especially flax), nuts (especially walnuts) and many herbs.
Estrogen is considered a female sex hormone produced by the ovaries in women. Without adequate levels of estrogen, women may notice that they feel moody, unhealthy, or are unable to maintain healthy female sex characteristics. Estrogen is an essential hormone for maintenance of feminine sex traits, but also plays an important role in physiological functions such as: promoting sex drive (libido), vaginal health, skin health, triglyceride regulation, and speeding the metabolism.
While there are many synthetic, pharmaceutical drugs devised to increase estrogen levels in women, these interventions aren’t always necessary. There are some natural ways to increase estrogen levels, one of which happens to be eating the right foods.
Phytoestrogens can work in various ways inside the body. While they mimic the effect of estrogen at low doses, they can actually block human estrogen at high doses. In addition, phytoestrogens can interfere with tumor cell growth, which may help prevent cancer, or they can alter DNA processes, which could have detrimental effects.
Three Types of Phytoestrogens
Below are three common types of phytoestrogens derived from foods. Certain foods may contain multiple types of phytoestrogens, but one may be dominant.
- Coumestan: Phytochemicals called “coumestans” contain a compound called “coumestrol.” Coumestrol is known to elicit estrogenic effects and is considered a phytoestrogen. Examples of foods with coumestrol include: alfalfa, legumes, pinto beans, soybeans, chick peas, and clovers.
- Isoflavones: This is another compound that is related to “isoflavonoids.” They act as phytoestrogens in people and are sometimes considered antioxidants. Examples of isoflavones include: soy products and legumes.
- Lignans: This is the third type of phytoestrogen derived from foods. Lignans are most commonly found in foods like brans, beans, fruits, and vegetables.
Food Sources of Phytoestrogens
Phytoestrogen content varies in different foods, and may vary significantly within the same group of foods (e.g. soy beverages, tofu) depending on processing mechanisms and type of soybean used. Legumes (in particular soybeans), whole grain cereals, and some seeds are high in phytoestrogens. A more comprehensive list of foods known to contain phytoestrogens includes:
- Soybean and soy products
- Linseed (flax)
- Sesame seeds
- Fenugreek (contains diosgenin, but also used to make Testofen®, a compound taken by men to increase testosterone).
- Mung beans
- Wheat germ
- Rice bran
- Licorice root
- Dried Apricots
- Red clover (sometimes a constituent of green manure).
- Dried Dates
- Dried Prunes
- Sunflower Seeds
7 – Health Benefits of Phytoestrogens
Reduce Risk for Cancer
In a study published in Environmental Health Perspectives, researchers reported that, in addition to their benefits for the glandular system, phytoestrogens have been shown to have antioxidant activity and can influence intracellular enzymes, protein synthesis, growth factor action, and cell proliferation in a way that makes them “strong candidates for a role as natural cancer-protective compounds.” The authors point out that countries or regions that consume the highest amounts of phytoestrogens also tend to have the lowest cancer rates. In another study published in the Journal of Epidemiology foods high in phytoestrogens were found to have a protective effect against endometrial cancer. In this nine-year study involving over 800 women, those who ate a diet rich in phytoestrogens showed a 54 percent reduction in the incidence of this cancer.
Although the jury is still out on the ability of dietary phytoestrogens to prevent osteoporosis, some hopeful findings indicate these plant compounds may have a role to play. Researchers at England’s University of Plymouth reported their studies reveal that phytoestrogens directly inhibit the effects of tumor necrosis factor-alpha, or TNF-alpha, which is a key factor in the development of postmenopausal and inflammatory bone loss.
Reduce Risk for Stroke
Stroke is the third most common cause of death for middle-aged and older women. A 50-year-old woman has about a one in five chance of suffering a stroke in her remaining lifetime. One of the most common causes of stroke is blockage due to atherosclerosis of the carotid arteries in the neck the arteries responsible for a major portion of the blood flow to the brain. Phytoestrogens have been shown to improve a women’s lipid profile to prevent strokes, similar to Premarin without the harmful side-effects associated with such drugs.
Prevents Breast Cancer
Although phytoestrogens mimic the behavior of estrogen – implicated as a possible cause of breast cancer – in a wide array of settings, these plant-based compounds appear to prolong the survival of women who have been diagnosed with breast cancer. A U.S.-Chinese research team studied the relationship between soy isoflavone intake and breast cancer outcomes of more than 9,500 U.S. and Chinese breast cancer survivors. After tracking study subjects for a mean period of more than seven years, researchers found that daily consumption of at least 10 milligrams of soy isoflavones significantly reduced the risk of breast cancer recurrence.
Help with Weight Loss
Apart from its other benefits, phytoestrogens seems to have the ability to regulate obesity, although the exactreasons are unclear.
Phytoestrogens are also known to increase libido. However, remember that excessive phytoestrogen intake over time is not advisable for men — moderation is the key.
Phytoestrogens for Menopause
Phytoestrogens in dietary form or standardized extracts may be beneficial for the menopausal symptoms. However, as the mixed evidence suggests, each phytoestrogen doesn’t necessarily work for everyone – you must find the combination or product that works best for you. Additionally, it’s clear that the type and potency of the phytoestrogen used alters the physiological effects on the body. One thing you can be sure of is that phytoestrogens are safe and reduces the symptoms and complications of menopause.
Side Effects of Phytoestrogens
The Linus Pauling Institute notes that the long-term safety of high doses of supplements containing one form of phytoestrogens, soy isoflavones, is still unclear. While diets containing soy and soy products should be considered safe, it may be best to avoid soy supplements, as they can contain higher levels of phytoestrogens. Foods containing phytoestrogens are likely safe and generally considered healthy. But there are few people who experience the below mentioned complications after consuming few these phytoestrogen source of foods.
Decreased Mineral Absorption
Soybeans have particularly high levels of phytic acid, preventing proper absorption of minerals such as calcium, magnesium, iron, copper, and zinc.
Allergic reactions to soy protein may include, sneezing, wheezing, coughing, hives, problems swallowing, anaphylactic shock, insomnia, ear and sinus infections, joint pain and chronic fatigue.
Flaxseed is high in fiber and causes the usual side effects in people not used to ingesting high fiber with their meals. Bloating, abdominal pain, gas, diarrhea, constipation, indigestion, heartburn and nausea may be experienced from including flaxseed in the diet.
The isoflavone genistein found in phytoestrogens from soy is known to cause stomach and other gastrointestinal problems including the erosion of the stomach lining from eating large quantities of soy products.