Shiitake Mushroom Health Benefits

Mushrooms have been used as a medicine in Asia for over 6000 years and are grown and consumed on a massive scale. Some people don't realize that mushrooms are a fungus, not a vegetable, and have no roots, leaves, flowers or seeds. Shiitake mushrooms, in particular, are popular because they are an excellent source of selenium and iron and a good source of protein, dietary fiber, and vitamin C. China grows over 3 billion pounds of Shiitake mushrooms a year and Japan grows over 200 million pounds of Shiitake mushrooms each year. In Japan, mushrooms make up so much of the average diet that they are one of the primary sources of protein for many people.

However, studies have shown that Shiitake mushrooms have health benefits far beyond their nutritional value.

Studies conducted over the last ten years have uncovered an active component in Shiitake mushrooms called eritadenine that lowers cholesterol levels for all types of fats eaten. And the more eritadenine given, the more the cholesterol levels drop. In a 1974 study (reported by Kenneth Jones in "Shiitake Medicine in a mushroom",Herbs for Health,Jan/Feb 1997), 40 elderly individuals and 420 young women consumed 9 grams of dried Shiitake (equivalent to 90g of fresh Shiitake) every day for 7 days. After a week, total cholesterol levels had dropped 7 to 15% in the older group and 6 to 12% in the young women.

Shiitake mushrooms have also been shown to shrink tumors, protect from cancer, and fight infection and disease. In 1969, scientists at Tokyo's National Center Research Institute isolated a polysaccharide compound from Shiitake they named lentinan. In laboratory trials, lentinan caused tumors in mice to shrink or vanish in 80 to 100% of the mice. Lentinan appears to stimulate immune-system cells to clear the body of tumor cells. Lentian injections are used in Japan to supplement radiation therapy and have been found to have positive results for cancer patients in the US, showing that it can reduce the size of tumors and increase the longevity of cancer patients. Lentinan's other healing benefit is its ability to support the immune system and help to fight infection and disease. Against influenza and other viruses, lentinan has been shown to be even more effective than prescription drugs. It even improves the immune status of individuals infected with HIV, the virus that can cause AIDS.

Another extract from Shiitake, LEM (short for Lentinula edodes myucelium) has been shown to be more lethal to HIV-infected cells than AZT, a medication developed to delay the progress of AIDS. LEM lignins have been shown to block HIV cells from reproducing and damaging helpful T cells. These lignins also stop cell damage from herpes simplex I and II, two viral infections that often plague individuals with HIV. In the 1980s, a trial involving 16 clinics in Japan investigated the impact of LEM on hepatitis B. The studies indicated that LEM may stimulate the body to produce antibodies. Forty individuals with chronic hepatitis B ingested six grams of LEM daily for four months. All of the patients experienced relief from hepatitis B symptoms, and in 15 patients, the virus was inactivated.

Most mushrooms contain L-ergothioneine, a powerful antioxidant. A research team at the 2005 American Chemical Society meeting revealed that mushrooms contain higher concentrations L-ergothioneine than either of the two sources previously believed to have the most: chicken liver and wheat germ. And L-ergothioneine is not destroyed when mushrooms are cooked.

A caution, mushrooms are high in purines which can be a problem for people who suffer from excessive accumulation of uric acid. Gout and kidney stones from uric acid can be related to excessive intake of purine-containing foods.

Adding mushrooms to our diet is looking like a very smart move.  After reading the research, we have added dried Shiitake and other mushrooms to our meals and are finding the taste of roasted mushrooms with garlic surprisingly pleasant.