What Is Genistein and What Role Does It Play in the Body?

What Is Genistein and What Role Does It Play in the Body?
Page content


Tofu Entree

Exactly what is genistein? A flavonoid antioxidant, this compound helps to protect cells from free radical damage. It also has several important functions that may indicate benefits for cancer patients and for the prevention of some types of cancer. Looking at the research on this antioxidant it may not be a bad idea to make sure genistein food sources are included in your diet.

Just an Antioxidant?

Genistein is an important protective antioxidant. It is classified as an isoflavone, which is a type of flavonoid. Isoflavones are found in high amounts in soy foods and are not only antioxidants with the potential to fight and prevent disease but they are also phytoestrogens, meaning they have a similar structure to human estrogen. Aside from genistein the most important isoflavone in soy is daidzein.

What are the specific actions of this compound? Genistein, like many other flavonoids, has anti-cancer properties. It inhibits the growth of blood vessels that nourish tumors, thus slowing the growth of a cancer in the body. This action has been helpful for prostate, breast and colon cancer. As a preventative aid genistein inhibits the enzymes that promote the formation of tumors. This antioxidant may be particularly beneficial for preventing cancers that are related to hormones, such as breast and ovarian cancer. As a phytoestrogen, genistein appears to enhance the positive effects of estrogen while preventing the negative effects of this hormone.

Genistein and isoflavones in general may also be beneficial for fighting osteoporosis. One of the reasons that menopausal women are at greater risk for osteoporosis is that they have diminishing estrogen levels. A deficiency of estrogen can cause a reduction in bone density. As a plant estrogen, genistein may help to retard bone loss.

This antioxidant is also beneficial for cardiovascular well-being. It helps to prevent the oxidation of LDL cholesterol, which would otherwise accumulate in arteries, leading to atherosclerosis. Genistein also impedes cell growth of cells that can form plaque along artery walls.

Cancer Research

There have been numerous studies to determine the benefits of genistein. There has been plenty of positive evidence; enough to encourage more research and investigation into how this antioxidant and other related compounds can benefit human health.

The most remarkable effect of genistein may be its ability to slow the growth and spread of cancer. This could make this antioxidant a helpful complementary aid in the treatment and prevention of some cancers, particularly breast and prostate cancer. According to a study published in Cancer Research, “Dietary Genistein Inhibits Metastasis of Human Prostate Cancer in Mice,” when studied in vitro genistein does inhibit “prostate cell detachment and cell invasion.” When fed to mice this antioxidant decreased the spread of cancer by 96 percent, although it did not change tumor growth.

Research published in the American Journal of Clinical Nutrition in 2000, “Protection against breast cancer with genistein: a component of soy, " finds that early exposure to soy foods may lead to cancer-protection benefits. Research is based on studies with rats. According to researcher Coral A Lamartiniere, the effects of genistein were looked at because it has mild estrogenic and antiestrogenic properties, it is an antioxidant and it inhibits the growth and spread of tumors. Also, women from Asian countries who consume a high-soy diet seem to have a low incidence of breast cancer.

It is important to point out that the research on genistein is not based on human clinical trials. While this compound seems to have many health benefits, particularly when consumed from food sources, it is not a form of treatment for cancer.

Food Sources

All soy foods are the best sources of genistein. Eating tofu and tempeh regularly and drinking soy milk as a substitute for regular milk or simply on occasion can increase your intake of genistein. Other legumes, such as fava beans, chickpeas, psoralea and kudzu are also good sources, although soybeans are by far the best sources. There is a small amount of genistein in cruciferous vegetables, such as broccoli and cauliflower, as well as alfalfa and sunflower seeds.

Understanding what genistein is and the potential of this flavonoid antioxidant you may want to consider making soy food products a regular part of your diet. There are not many other strong food sources aside from soy, but there are many types of soy foods to choose from. Supplements are another option for people looking for more genistein and other isoflavones. Before taking supplements always talk to your doctor first, especially if you have a medical condition and are taking any type of medication or are pregnant.


Gilbert, Monique N. “The Healing Power of Soy’s Isoflavones.” Feminist Women’s Health Center. https://www.fwhc.org/health/soy.htm

Lakshman, Minalini. Dietary Genistein Inhibits Metastasis of Human Prostate Cancer in Mice.” Cancer Research. https://cancerres.aacrjournals.org/content/68/6/2024.short

Lamartiniere, Coral A. “Protection against breast cancer with genistein:a component of soy.” American Journal of Clinical Nutrition, June 2000. https://www.ajcn.org/content/71/6/1705S.full

Messina M. “Soyfoods, soybean isoflavones and bone health.” Journal of Renal Nutrition, 2000, US National Library of Medicine Archives. https://www.ncbi.nlm.nih.gov/pubmed/10757817

Page, Linda. “Healthy Healing: A Guide to Self-Healing for Everyone, 11th Edition” (Traditional Wisdom, 2003).

photo by Joy/flickr