Phytoestrogens - A Safer Alternative to
Estrogen Replacement Therapy
by April Nance,

Assistant Product Manager, Marketing Nature's Sunshine Products Inc.

American women have taken an increased interest in phytoestrogens recently as they search for a natural way to help balance hormone levels in their maturing years. Phytoestrogens--or plant compounds that have actions similar to estrogen-may provide needed support in a safer way than hormone replacement.

Estrogen-like plant compounds were discovered in the 1940's as an epidemic of infertility spread among sheep grazing on red clover.

Estrogen: Too Much Of a Good Thing?
Early studies of estrogen as treatment for menopausal symptoms and hormone replacement therapy showed promising results for these conditions and for the prevention of osteoporosis, cardiovascular disease and various cancers. However, more recent studies reveal that these treatments are not as safe as were once thought. An article in USA Today stated that estrogen used in hormone replacement therapy is being considered for listing in the next federal "Report on Carcinogens." It is becoming well accepted that estrogen promotes endometrial cancer as well as a small increase in the risk of breast cancer.

Many women experience already-high levels of estrogen in the body, which contribute to increased risks for endometrial, ovarian, uterine and breast cancer, gallbladder disease, strokes, heart attacks and other cardiovascular diseases. Women who eat the typical Western diet tend to have fewer days between menstrual cycles and are thus exposed to more estrogen. According to Dr. Brett of Prevention magazine's Prevention Nature's Medicine, "One of the biggest reasons women get into trouble with breast cancer is too much estrogen floating around in their bodies." Although both synthetic and natural estrogens increase the aforementioned risks, phytoestrogens have not been associated with these side effects.

Researchers theorize that the Western diet alters hormone production, metabolism or biochemical action at the cellular level, contributing to increased risks of breast and other hormone-dependent cancers. Animal proteins and the lack of fiber, antioxidants and other essential nutrients contribute to the poor quality of a Western diet compared to that of Asian cultures such as Japan and China. Significant differences exist between risk factors for those eating an Asian or vegetarian diet and those eating a typical Western diet. This is attributed in part to consumption of phytoestrogen-containing foods-especially soy products. A typical Asian diet includes 20-80 mg of the soy
isoflavone daidzein per day while the average American consumes only 1-3 mg per day of this valuable nutrient.

Estrogen is one of few hormones that can be mimicked by plant compounds. Most other hormones require precise molecular shapes to bind with receptors, but estrogen receptors can bind with many plant compounds. Phytoestrogens mimic estrogen in the body. Typically, their effect is about 2 percent of that of estrogen.

Phytoestrogen content in the diet can be determined by measuring the amount of equol, an isoflavone metabolite, in the urine. The average Western diet consumer excretes 0-300 nM/day, while a vegetarian excretes about 20,000 nM/day. Diet patterns can be directly tied to the differences in symptoms and risk factors that exist between cultures. In cultures that consume mostly vegetarian diets, women rarely experience hot flashes and other menopausal symptoms. Studies have shown that when Asians begin consuming a typical Western diet, their risk factors increase to those of the average Westerner. Many diseases of the Western hemisphere are hormone-dependent cancers associated with excess estrogen. Phytoestrogens that inhibit the actions of estrogen may lower the risks of such cancers.

Understanding and Using Phytoestrogens
Phytoestrogens are found in many plants from legumes and grains to fruits and nuts. Strength, concentration and actions of phytoestrogens vary from plant to plant. Some have antifertility, antimicrobial or anti-angiogenic (inhibits the formation of new blood vessels) properties.

Phytoestrogens are classified into three groups: isoflavones, lignans and coumestans.

Isoflavones are found in many plants, including soybeans, licorice, kudzu, alfalfa, black cohosh and red clover. They act both on receptor sites for estrogens as well as on the enzymes that metabolize them. Certain isoflavones are natural cancer-protective compounds.

Genistein is the most potent phytoestrogen discovered to date. It is found in high concentrations in both soy products and red clover. A typical concentration of genistein in soy foods is 1-2 mg per gram of soy protein. It has been proven to have a number of benefits for the prevention of breast cancer, prostate cancer, high cholesterol, alcoholism, osteoporosis and menopausal symptoms. It also helps protect against tumors by stopping blood vessels that supply tumors from being produced. It has an affinity for estrogen receptors 1/100 that of estradiol.

Daidzein is a less potent isoflavone also found in soy and red clover. Its preventative effects are similar to those of genistein. It has also been studied extensively as a possible safe therapeutic agent for alcohol abuse.

Biochanin A, an isoflavone found in red clover, has been reported to inhibit cargcinogenic cell activity in cell cultures.

Formononetin is a weakly estrogenic isoflavone found in red clover and black cohosh.

Lignans are found in many fruits and seeds such as flax seeds. They produce a compound that causes the body to excrete estrogen in the urine, decreasing its ability to influence breast cancer. Studies show that breast cancer rates are lower in women who excrete higher amounts of lignans in their urine. Prostate cancer risks are lower in men who consume high amounts of lignans. In studies, flax seed oil has also been associated with a decreased risk of colon cancer.

Phytosterols are chemicals- (found in plants) that contain a steroidal nucleus and are similar to the steroidal hormones found in humans. They also exhibit estrogenic effects. Fat-soluble phytosterols are found in high concentrations in legumes, seeds and nuts. These plant steroids include cholesterol, diosgenin and B-SitoSterol. Increased consumption of phytosterols is associated with a decrease in blood cholesterol as well as decreased risks of some cancers, especially breast cancer.

Coumestans are found in alfalfa and red clover. They support the body's efforts to balance estrogen levels by triggering estrogenic activity when estrogen levels are low and by competing for estrogen receptor binding sites when estrogen levels are high.

Animal and clinical studies have revealed a number of beneficial physiological actions associated with phytoestrogen consumption. These include:

  • inhibition of estrogen receptor binding sites
  • interference with sex hormone releasing hormones (gonadotropins)
  • inhibition of estrogen production
  • an increase in synthesis of estrogen-binding protein (decreases activity of free estrogen)
  • antioxidant activity against estrogen-generated cancer cells.

    Phytoestrogens may hold the key to greater balance and happiness for millions of women. Get informed and get feeling better!

    Source:soybeans, licorice, kudzu, alfalfa, black cohosh, red clover.fruits, seeds, flax seed oil, soy products.alfalfa, red clover
    Actions:Genistein (soy, red clover) helps prevent cancers of the breast and prostate. Supports healthy cholesterol levels. Supports hormonal balance.

    Daidzein (soy, red clover) provides nutritional support similar to genistein.

    Biochanin A (red clover) may inhibit carcinogenic cell activity in cell cultures.

    Formononetin (black cohosh, red clover) supports hormonal balance, especially during menopause.
    Promotes the excretion of estrogen in the urine.

    Breast cancer rates are lower in women whose urine lignan concentration is higher.

    Prostate cancer risks are lower in men who consume more lignans.
    Modulate estrogen levels by stimulating estrogenic activity when the body's hormone levels are low, and by competing for its binding sites when levels are high.

    Phytosterols (found in plant oils from legumes, seeds, nuts).

    B-sitosterol (soybeans, saw palmetto, red clover) exerts an estrogenic effect.

    Diosgenin (wild yam) acts as a precursor to many hormones. Competes with estrogen for receptor sites.