https://www.verywellhealth.com/isoflavones-benefits-side-effects-dosage-and-interactions-4687017
Untitled Document
Isoflavones are considered a type of nutritional supplement produced almost exclusively by the Fabaceae (Leguminosae or bean) family. They are a specific group of molecules that comprise what is called a phytochemical (natural plant chemical) found in foods like legumes, and herbs like red clover. Isoflavones are considered phytoestrogens, meaning that they are similar in structure to the female hormone, estrogen. Isoflavones are also considered anti-oxidant compounds. This means that they reduce damage due to oxygen (such as that caused by free radicals) and may help fight against certain types of cancer.
There have been multiple studies on the benefits and safety of isoflavones. In fact, isoflavones may be the most controversial natural supplement, when it comes to weighing the benefits against the risks because much of the medical research varies.
Health Benefits
When it comes to food items, soybeans contain the highest level of isoflavones. Herbal sources that are rich in isoflavones, including red clover (Trifolium pratense) and alfalfa (Medicago sativa). Like soy, red clover is considered a legume that contains phytoestrogens.
In their most common form, soy isoflavones include genistein, daidzein and glycetein. Isoflavones found in red clover include formononetin, biochanin A, daidzein, and genistein.
It’s important to note that taking a supplement source of isoflavones and eating a food/protein source of isoflavones—like tofu, tempeh, soy milk, miso, or other soybean products—produces different results (for benefits and side effects).
Isoflavones and Estrogen
Estrogens are hormones that influence sexual and reproductive development, primarily in women. Having a similar structure to estrogen allows isoflavones to bind with estrogen receptors. Depending on the hormone status of a person, isoflavones can affect a person in the same way that estrogen doesbyproducing either estrogenic or antiestrogenic effects.
In studies involving isoflavone supplements for menopausal symptoms, some benefit has been shown, such as improving fatigue and irritability and decreasing hot flashes. But, according to The Pharmaceutical Journal, although isoflavones are being marketed as an effective product for natural hormone replacement therapy (HRT), further research is needed and consumers should NOT use isoflavones for long-term HRT until more research is done to prove the safety and efficacy of the products.
In addition to providing menopause relief, isoflavones are said to prevent some types of cancer and protect the heart. Several studies have shown that soy protein supplementation (containing isoflavones) reduces both the total and low density (LDL) cholesterol in animal and human studies.
But there are conflicting study results on isoflavones—some showing benefits to health and others indicating harmful side effects.
Some case reports indicate that isoflavones in red clover help reduce hot flashes and anxiety during menopause. Although the herb is marketed as a dietary supplement called Promensil, the National Women’s Health Network reports that there is a lack of sufficient clinical research data to back up these claims. Red clover has, however, been found to have a cardiovascular benefit, raising good cholesterol called HDL.
Soy in the Diet
In Asia, where soy is eaten as a regular staple, the rate of heart disease, breast cancer, and prostate cancer is lower than in the U.S. But many Asians ingest soy differently than in Western countries.
For example, Asians notoriously eat much larger quantities of soy daily. It’s also common in the East to eat fermented forms of soy, including miso, tempeh, and tamari. It is thought that fermentation helps with the digestion of soy and may even promote the body’s ability to absorb isoflavones.
Many health experts feel that eating fermented soy in moderation may:
- Increase bone density
- Help to prevent breast and uterine cancers
- Lower the incidence of prostate cancer
- Lower bad cholesterol levels
- Improve mental functioning
- Reduce muscle soreness (particularly after exercise)
Medical Uses
There are many common medical uses for isoflavones. Conditions that may improve with the use of isoflavones vary.
Breast cancer: The research is mixed. Those who eat a high soy diet during adolescent years may have a lower risk of breast cancer later in life, but some studies show that isoflavones from soy can increase the risk of cancer.
Type 2 diabetes: The research says that eating soy protein or fermented soy may reduce blood sugar in those with diabetes.
Diarrhea in infants: Soy formula supplementation may shorten the duration of diarrhea (compared to drinking formula from cow’s milk). It’s important to note that in adults, soy fiber was NOT found to improve diarrhea.
High cholesterol: The clinical research evidence strongly suggests that isoflavones from soy reduce bad cholesterol called LDL. It’s important to note that ONLY the protein-based food sources of isoflavones such as tofu, tempeh, and other soy products were found to lower cholesterol; isoflavone supplements were not found to be effective.
High blood pressure: Eating soy may lower the blood pressure slightly and is suggested for those with slight increases in blood pressure, but NOT in people with severely elevated blood pressure.
Irritable bowel syndrome (IBS): Some research found that soy isoflavones may improve symptoms of IBS, such as abdominal pain.
Menopausal symptoms: Symptoms such as irritability, depression, and hot flashes may be lessened with the use of isoflavones. However, isoflavones were NOT found to be beneficial for night sweats.
Osteoporosis: In studies, soy protein from food sources and isoflavones in supplement form were both found to increase bone density.