The Power of Mushrooms
Mushrooms arouse mixed feelings in many people. Of the 38,000 types of mushrooms, only about 50 are poisonous, and another 50 have medicinal value. However, several prominent historical figures — Claudius II, Pope Clement VII, and Buddha — were poisoned to death by ingestion of mushrooms, and thus, the image of mushrooms as potentially fatal lingers on in some minds.
Nonetheless, in the last decade, there has been increasing recognition in the Western world of the beneficial effects of certain types of mushrooms. In Japan and China, legends about the ability of medicinal mushrooms to preserve youth and increase longevity date back centuries. It is, however, only in the last 20 years has scientific research provided a factual basis for these legends.
In Japan, the shiitake mushroom is the most popular mushroom for culinary purposes. One of its extracts, called lentinan, was approved as an anticancer drug in the 1980s in Japan thanks to its ability to stimulate the immune system. However, for medicinal purposes, it was less than ideal since it had to be injected intravenously and was not effective by oral administration.
There are other mushrooms with medicinal value such as reishi, Cordyceps, lion’s mane, turkey tail, and Agaricus. These mushrooms not only stimulate the immune system but are also a rich source of amino acids, vitamins, and minerals while containing little fat or cholesterol and few calories.
No mushroom, though, has been found to provide the health benefits of the maitake mushroom. It wasn’t until the late 1980s that a technique for artificial cultivation of maitake was devised in Japan, making it possible to conduct research on its properties. Moreover, they discovered that in animals, maitake is clinically effective when taken by intraperitoneal injection or by oral administration. Subsequently, the focus of research and culinary interest in medicinal mushrooms switched from shiitake to maitake.
The ingredient in maitake that confers its medicinal properties is a complex carbohydrate called beta-glucan, which comes from the fruiting body of the mushroom. The chemical structure of this large and heavily branched molecule is similar to that found in other mushrooms or natural products such as yeast and oat bran. However, maitake’s beta-glucan is more heavily branched than the others and has proven to be more effective in activating immune cells that attack infection or cancer, and in the production of immune-modulating molecules such as interleukins and cytokines. A water-soluble extract consisting of this glucan bound to protein — called the D-fraction — is the bioactive material of interest for immune modulation.
A study was done comparing the cytotoxic capabilities of the D-fraction of maitake with beta-glucans from other mushrooms and natural products such as the recognized immune system booster arabinoxylan. This study looked at the ability of these compounds to kill prostate cancer cells in cell culture. Maitake’s D- fraction was by far the most potent. What makes maitake truly unique among mushrooms and other natural products used for health benefits is its wide range of actions on many disease conditions. While the so-called D-fraction is effective as an antitumor agent and immune system modulator, it has also been found to prevent cell death in helper T-cells infected by the HIV virus. Some doctors have used the maitake liquid extract topically applied to Kaposi’s sarcoma, a lesion frequently found in AIDS patients, and have seen a reduction in the size of the lesion.
In addition to these immunological benefits, recent research has shown a remarkable effect of another extract of maitake on the medical conditions collectively known as syndrome X. Syndrome X includes such metabolic disorders as elevated glucose, insulin, cholesterol and triglyceride levels along with hypertension and obesity. Taken together, these conditions constitute a significant risk for diabetes, cardiovascular disease, and stroke. The D-fraction has been shown in numerous clinical studies to reduce levels of all of the above indicators in rats and mice.
In humans, there is mounting evidence that this fraction, consisting of a glycoprotein, is an effective product for the treatment of the hyperglycemic condition found in type II diabetes. In addition, when consumed as the SX-fraction, maitake has caused weight loss in both animals and humans.
Medicinal mushrooms are neither plant nor animal, but instead, are a fungus with a wide variety of healing powers attributed to them by myth and now substantiated by scientific proof. While once the food of emperors in Japan and the pharaohs in Egypt, they are now accessible to ordinary consumers.