Many plants produce chemicals called phyto-hormones, which mimic or interact with hormones in humans and animals. Phytoestrogens are plant-produced chemicals that mimic oestrogen, the primary sex hormone in women. Oestrogen is manufactured mainly in the ovaries and is responsible for the menstrual cycle. Men’s bodies produce oestrogen to a lesser degree. Oestrogen is crucial to the female reproductive cycle.
Phytoestrogens can behave in the body like the hormone oestrogen. They can also block the effects of the body’s natural supply of oestrogens. Some evidence suggests that soy foods may be linked to lower risk of endometrial. prostate, breast and bowel cancers, brain disorders and a lowered risk of bone loss osteoporosis in women.
Phytoestrogen also exhibits beneficial effects in regard to obesity and diabetes. In obese individuals, dietary soy intake increased high-density lipoprotein, or HDL cholesterol and decreased low-density lipoprotein, or LDL cholesterol.
There are 20 categories of phytoestrogens. Isoflavones, flavones, deoxybenzoins, coumestans and lignans are all classes of phytoestrogens.
- Isoflavones from soya beans, lentils, and other legumes.
- Lignans from flaxseed, cereal grain, and vegetables.
- Coumestans from red clover, sunflower seeds, and bean sprouts.
Soya bean isoflavones showed improvement in vaginal symptoms (dryness, irritation, painful intercourse) in studies.
Phytoestrogens have beneficial effects on bone health in menopausal women. Some women may find that eating a diet high in phytoestrogens helps their menopausal symptoms, in addition to providing other health benefits. In some Asian cultures, where women consume 50-200 mg of isoflavones daily, hot flashes are rare as compared to Americans, whose typical diets contain only 3-5 mg daily.
Soya, in particular, improves cholesterol levels and is a great plant source of protein. The highest quantities of isoflavones are found in less-processed foods and fermented soy products. The best food sources include soya beans or edamame, soy nuts, tofu, tempeh, and miso
Natural sources of phytoestrogens in alphabetical order
- Legumes
- Lentils
- Liquorice root
- Mint
- Mung beans
- Oats
- Peaches
- Pistachios
- Pomegranates
- Potatoes
- Rice (brown)
- Rice bran
- Rye
- Sesame seeds
- Soybeans (tofu)
- Sunflower seeds
- Wheat germ
- Wholegrains
- Winter squash
- Yams
NOTE: Flaxseed is a great source of phytoestrogens, fibre, and alpha-linolenic acid (a source of omega-3 fatty acids). All small seeds must be ground in order for them to be adequately digested.
Related subjects
- A-Z of nutrients
- Bone and joint disorders
- Cancer
- Diabetes
- Heart disorders (high cholesterol)
- Menopause and andropause
- Obesity
- Skin disorders