Edible mushroom that grows in late summer and autumn at the base of broad-leaved tree stumps in areas with a temperate climate; it has a bushy appearance with dense clusters, it can also reach large dimensions and is sought after for its sweet taste. It is known by the Japanese name Maitake which means “dancing mushroom” probably because those who found it in the feudal period danced for joy, as they could have sold it for the equivalent weight in silver. The properties of this mushroom have been known for many centuries.

– Scientific studies carried out in the 1980s by the Japanese mycologist Hiroaki Nanba have verified that Grifola frondosa is rich in polysaccharides with a particularly complex structure with chains with a high degree of branching and high molecular weight. These two characteristics are particular factors that make these beta-glucans unique with important stimulating effects on T lymphocytes, dendritic cells and macrophages and therefore with an enhancement of the entire immune system. Dr. Nanba isolated a polysaccharide fraction (D fraction) which he subsequently purified to obtain a new one (MD fraction) with better therapeutic effects. Studies have shown that fraction D increases the production of cytokinins by macrophages and dendritic cells with an enhancement of the cytotoxicity of NK cells towards cancer cells. Grifola has a direct action on cancer cells as it blocks their metabolism and can slow down the growth of the tumor mass. It has been verified that the fungus has a powerful antimetastatic action and its daily use for long periods is recommended after a diagnosis of neoplasm. A study on 10 laboratory mice carrying MM46 carcinoma given high doses of the fungus for one month resulted in complete tumor remission in 4 animals and a 90% reduction in the other 6. In an in vitro study, hormone-resistant prostate cancer cells were treated with a purified extract of Grifola and after 24 hours 95% of them were induced to apoptosis. Another study on 146 patients with bladder cancer evaluated the comparison of the administration of the fungus with synthetic chemotherapy as a prevention for relapses and the results confirmed a similar action to the drug. Other studies have shown that the antitumor and antimetastatic action of Grifola frondosa has been obtained in the treatment of non-hormone-dependent prostate, lung, bone, colon, liver and breast cancer. Further studies have verified the compatibility of Maitake with different chemotherapeutics with an enhancement of the therapeutic effect of the drug and a protective action against healthy cells. Furthermore, Grifola reduces side effects such as loss of appetite, nausea, vomiting, hair loss and pain. Even high dosages of the mushroom did not cause side effects and it is recommended to take it together with vitamin C to enhance its effects.

– Grifola frondosa like other mushrooms has hypoglycemic effects, but its action is not aimed at limiting the intestinal absorption of glucose, but rather increases its metabolization by the cells. It stimulates and strengthens pancreatic cells, improves the function and amount of insulin in the blood and sensitizes cell receptors to bind to the hormone more effectively. It is therefore useful in case of type II diabetes, when insulin resistance persists and a decrease in peripheral sensitivity to the hormone.

– Several studies conducted on animals subjected to a high-calorie diet and on overweight people have shown that Maitake has an action of inhibiting the synthesis of triglycerides and reducing blood lipid levels. The intake of Grifola frondosa stimulates the use of the fats accumulated in the adipose tissues with the reduction of the sense of hunger and the need for carbohydrates and fats from the outside. It inhibits the differentiation of adipocytes as it hinders the biochemical processes that lead to the transformation of normal cells into adipose tissue. Furthermore, the assumption of the mushroom has proved useful in reducing lipidemia and in particular LDL cholesterol. The use of this mushroom is therefore useful for reducing weight and can be an effective adjuvant in food diets.

– The Maitake has a hepatoprotective action as it is able to stimulate the inactivation of toxins following a poor diet. A study has shown that the mushroom is able to reduce liver damage caused by D-galactosamine with dose-dependent effects. It also inhibits the accumulation of fat in the liver and has been shown to be useful in the treatment of chronic hepatitis B.

– Grifola frondosa promotes the synthesis of vitamin D important for the metabolism of calcium and can consequently be useful for strengthening bones and fighting osteoporosis.