Shiitake – Lentinula edodes

The shiitake is called the “king of medicinal mushrooms” due to its versatile use and as it was one of the first to be used as a medicinal mushroom in our part of the world.

The shiitake is highly valued in East Asia not only as a medicinal mushroom. Owing to its particularly aromatic taste, it has already been established in East Asian cuisine for many centuries.

It occurs naturally in China and Japan. It grows especially on deciduous trees with hard wood. The skin of the pretty light to dark brown cap is usually covered with delicate flocks. On young mushrooms, the edge of the cap is rolled inwards. The lamellae are smooth to rough and its stalk usually sits in the middle of the cap.

The name shiitake is derived from the combination of two Japanese words: “Shiia”, which means a mushroom that grows on a Shii tree (a hardwood tree), and “Take” which translates simply as mushroom. In China it is also known as Xiang Gu, which could be interpreted as “fragrant mushroom”. In Asia, the shiitake has been regarded for a long time as the king of mushrooms due to its important constituent substances. During the Ming Dynasty (1368-1644) it was already prized as a medicinal food and used against various illnesses. According to Asian folk medicine, it is a tonic that regulates the vital energy qi, balancing yin and yang and activating the blood.

Main areas of use in mycotherapy:

Various constituent substances of the shiitake mushroom have a verified pharmacological effect. It contains eritadenin, a derivate of the purine base adenine. It has an anti-aggregative effect on thrombocytes and is therefore antithrombotic. Eritadenin also influences the phospholipid metabolism in the liver and therefore reduces the blood lipids, especially serum cholesterol. It does not suppress the cholesterol biosynthesis but accelerates the elimination of cholesterol. It has also been established that by taking shiitake, the ratio of lipoproteins shifts in favour of HDL. This results in an increased elimination of cholesterol from the vessels and a faster breakdown of cholesterol in the liver. The protective effect of HDL consists in the fact that, firstly, cholesterol is removed from the tissue and the macrophages and, secondly, it carries enzymes with it that can break down oxidised lipids.

Shiitake inhibits inflammations and regulates cholesterol, reducing the risk of foam cells being deposited on the artery walls causing arteriosclerosis. In addition, it has the benefit that the high blood pressure caused by vascular deposits can be positively influenced. The effect of reducing blood pressure is brought about by the enzyme tyrosinase, which studies have proven is contained in the shiitake mushroom.

The macromolecular polysaccharide Lentinan is a further constituent substance. It is used primarily clinically as an immune therapy for tumour patients, as it activates the immune response and has an inhibiting effect on the growth of tumours.

Highly malignant cells have a protective mechanism: they block the synthesis of type TH1 cytokines. The Lentinan activates the complement system in an alternative way through stimulation of the macrophages and activation of the TH1 cells. The released IL-2 then significantly suppress tumour growth. The shiitake therefore provides support especially for patients who are not yet in traditional medical treatment. It is not surprising that its substance Lentinan has been approved for a long time in Japan as a medicine for the treatment of cancer.

Apart from Lentinan, the shiitake mushroom also contains other polysaccharides that have an anticarcinogenic and immunoregulatory effect. The beta-glucans (polysaccharides) of the shiitake can also activate endogenous antioxidant enzymes such as superoxide dismutase, catalase and glutathione peroxidase. This is very important for detoxification and as protection against cell damage and inflammations.

In western mycotherapy, it is mainly used against arteriosclerosis and circulation disorders. As blood flow can be regulated by influencing the vessel tone through the shiitake, it is also used successfully in cases of migraine and tinnitus.

The shiitake mushroom is also effective against metabolic disorders or diseases caused by metabolic changes with swelling and pain of the joints. Like the reishi, this medicinal mushroom has been proven beneficial in mycological practice especially also for arthritis, gout and rheumatism. It can reduce the pain of these conditions and improve mobility restrictions.

The hepatoprotective properties of shiitake are also worth a mention. Taking this medicinal mushroom provides protection for the liver cells and an improved liver function. In cases of hepatitis B it has been shown that the production of antibodies against it was stimulated. It was also observed that the SGPT and GPT level in toxic hepatitis was regulated by the Lentinan.

In general, shiitake is a mushroom that builds up and strengthens. Due to its B vitamins, it is also recommended for exhaustion, overworking and chronic fatigue syndrome. Furthermore, it enriches the diet of vegetarians and vegans, as shiitake contains ergosterol, a precursor to vitamin D that is otherwise contained especially in meat.

Effects proven by studies:

• change in the phospholipid metabolism in the liver leads to a lowering of the cholesterol level
• tyrosinase reduces blood pressure

Areas of use in Traditional Chinese Medicine:

Characteristics: sweet, neutral

• Spleen, stomach, lungs
• regulates qi and blood in case of depletion but not blockades
• dissolves mucous
• strengthening of the core and qi
• helps rashes to clear up
• for lack of appetite and energy
• for frequent urination
• for rickets
• for stomach and uterus carcinoma
• for hyperlipaemia

Sources

• Sugiyama K., Akachi T., Yamakawa A.: “Hypocholesterolemic action of eritadenine is mediated by a modification of hepatic phospholipid metabolism in rats.”; The Journal of Nutrition, Vol. 125 (8); 2134-44
• Jianzhe Y., Mao X.: “Icons of Medicinal Fungi from China”; CRC Press; 1989
• Hobbs, C.: “Medicinal Mushrooms”, Botanica Press, 1995
• Prof. Dr. med. Ivo Bianchi: “Moderne Mykotherapie”; Hinckel Druck, 2008

Note: the described effects are based on taking medicinal mushroom powder made from the whole mushroom. Please consult your therapist before use.