The Mushroom Council: Mushrooms as Potential Disease Fighters
The Mushroom Council provides information on the many varieties of mushrooms, conducts research into their disease-fighting properties, assists mushroom growers and retailers, and disseminates information on how to grow, store, and use mushrooms.
Mushrooms as Potential Disease Fighters
Eastern cultures have regarded the mushroom as an important ingredient and acknowledged their medicinal values for centuries. There are more than 50 species which are believed to have healing properties when taken as a tonic or as food. Historical accounts state these properties may help with anything ranging from an upset stomach to poor circulation to colds and flus. Mushrooms, often grouped with vegetables and fruits, are actually a class of their own: they are fungi. Although they share many of the nutrition attributes of fruits and vegetables, they offer a few of their own. Mushrooms are a good source of B vitamins—riboflavin, niacin, and pantothenic acid. They are also an important source of minerals such as selenium, copper, and potassium.
Selenium is an essential trace mineral which functions as an antioxidant. Mushrooms accumulate selenium based on the soil content, with levels being the highest in those grown in the Midwest. A serving of shiitake or crimini mushrooms provides about one-third of the recommended daily value for selenium. Selenium works closely with Vitamin E, also an antioxidant, to minimize free radical damage leading to cancer, particularly prostate cancer and heart disease, and plays a role in alleviating symptoms associated with rheumatoid arthritis. Epidemiological studies suggest an inverse relationship between selenium intake and the incidence of certain cancers. Research findings from the Physician's Health Study also found an inverse relationship with pre diagnostic plasma selenium levels and risk of advanced prostate cancer in men. Given these studies and other important published reports for selenium and prostate cancer risk, the National Cancer Institute has launched a large prevention trial involving 32,000 men to compare the effect of selenium and Vitamin E (the selenium and Vitamin E cancer prevention trial). The results of this trial are expected to be released after seven to 12 years of participation, approximately in the year 2013.
Formal studies, mostly done in Asia, provided early scientific data that substances extracted from mushrooms can be beneficial in the treatment of certain types of cancer by enhancing immune function. Today, these studies are the foundation for recent findings which actually confirm these concepts and provide additional insight to the specific mechanisms. Mushrooms contain polysaccharides, a form of carbohydrate, which contain unique properties. In medicinal mushrooms, such as shiitake and maitake, these polysaccharides are thought to have potent anti-tumor compounds. The mechanisms by which these polysaccharides influence the immune system and exert their anti-tumor effects have been reviewed by scientific studies. Some of the evidence indicates that these compounds enhance the numbers and/or functions of macrophages, natural killer cells and subsets of T cells. These compounds can thus stimulate the immune system to allow for a slower growth or spread of cancer cells during cancer treatment. Preliminary Japanese studies also find that maitake mushrooms, also known as "hen of the woods" and "dancing mushrooms" contain compounds which may have the ability to decrease blood pressure as well as blood cholesterol levels. These initial studies have prompted many more researchers around the world to take a serious look at the variety of protective nutrients and compounds in mushrooms.
The Beckman Research Institute of the City of Hope in California is currently examining the specific mushroom chemicals which suppress breast and prostate cancer growth. This current research suggests that white mushrooms contain phytochemicals which may reduce the growth of the breast tumors by reducing the level of estrogen formed, a recognized risk factor in breast cancer development. The white mushroom contained higher amounts of these phytochemicals when compared to other sources such as green onion, celery, carrot, bell pepper, and broccoli, as well as other forms of mushrooms such as portabellos, shiitake, and crimini.
As part of everyday health concerns, one cannot ignore the unprecedented levels of obesity in America today. Health professionals and food service operators are committed to endeavors which explore ways to deliver nutritious and flavorful meals to all ages. Mushrooms, a low-calorie, low-fat food, provides menu development ideas to not only offer variety and global flavors, but also act as a substitute for higher calorie/fat foods. Mushrooms also contain a high water content, over 90 percent, which can contribute to a feeling of fullness. Mushrooms also contribute a unique flavor profile, which for many individuals who are seeking a vegan-style dish or trying to eat a healthy plant-based diet, can make a flavor difference. Mushrooms provide a unique flavor or sensation, which is described as "umami." This sensation has made many different varieties of mushrooms a popular substitute for meat recipes. The Japanese define umami as "deliciousness," or the fifth sense—a taste distinct from sweet, salt, bitter, and sour. It has also been further described as the "savory" or "meaty" flavor of dishes. Umami, a taste and a flavor enhancer, is produced by the compound glutamate. Glutamate is detected by certain receptors on the tongue, thus supporting the case for making umami the fifth sense. Mushrooms contain glutamate in an abundant amount, and also other important chemicals which work at the tongue receptor site to intensify the taste sensation of the glutamate.
Suggested Reading
Li, H., Stampfer, M.J., Giovannucci, E.L., Morris, J.S., Willett, W.C., Gaziano, J.M., Ma, J. A prospective study of plasma selenium levels and prostate cancer risk. J Natl Cancer Inst. 2004;96:696-703.
Lipsky, K., Zigeuner, R., Zischka, M., Schips, L., Pummer, K., Rehak, P., Hubner, G. Selenium levels of patients with newly diagnosed prostate cancer compared with control group. Urology. 2004;63:912-916.
Allen, N.E., Morris, J.S., Ngwenyama, R.A., Key, T.J. A case-control study of selenium in nails and prostate cancer risk in British men. British Journal of Cancer. 2004;90:1392-1396.
Beelman, R.B., Royse, D.J., Chikthimmah, N. Bioactive components in button mushroom Agaricus bisporus (J.Lge) imbach (agaricomycetideae) of nutritional, medicinal and biological importance. Review. Int. J of Med Mushr. 2003;5:321-337.
Brooks, J.D., Metter, E.J., Chan, D.W., Sokoll, L.F., Landia, P., Nelson, W.G. et al. Plasma selenium level before diagnosis and the risk of prostate cancer development. J Urol. 2001;166:2034-2038.
Broome, C.S., McArdle, F., Kyle, J.A.M., Andrews, F., Lowe, N.M., Hart, C.A., Arthur, J.R., Jackson, M.J. An increase in selenium intake improves immune function and poliovirus handling in adults with marginal selenium status. Am J. Clin Nut.r 2004;80:154-62.
Zhao, L., Zhao, G., Zhao, Z., Chen, P., Tong, J., Hu, X. Selenium distribution in a Se-enriched mushrooms species of the genus Ganoderma. J. Agric. Food Chem 2004; 52:3954-3959.
Grube, B.J., et al. White button mushroom phytochemicals inhibit aromatase activity and breast cancer cell proliferation. J Nutr. 131:3288-3293, 2001.
Combs, Jr., G.F. et al. Reduction of cancer risk with an oral supplement of selenium. Biomed Environ Sci, 10:227-234, 1997.
Brooks, J.D. et al. Plasma selenium level before diagnosis and risk of prostate cancer development. J of Urology, 166:2034-2038, 2001. Wood, M. Selenium's secrets probed in new study. News from the USDA Agricultural Research, March 2002. http://www.ars.usda.gov/is/pr/2002/020315.htm