Lentinan: The Shiitake Polysaccharide Studied in Cancer Immune Support

Medicinal mushrooms

Mushrooms have always held an unusual place in the human psyche and in our evolution, long associated with power and mystery — used for food, ritual, and, of course, healing. Mushrooms are neither plants nor animals, which makes them especially attractive to scientists, because they contain a range of substances found nowhere else. It all began with the antibiotic penicillin (extracted from the Penicillium mushroom), estimated to have saved up to 200 million lives.¹ The rapidly growing volume of research worldwide proves the value of mushrooms for treating and preventing health problems. Few people know that active compounds extracted from mushrooms are widely used in medicine: antibacterial agents,² the statins used to lower cholesterol (also derived from a mushroom, patented in 1979),³ and antifungal drugs.

How cancer cells protect themselves from immunity

Normally, immune cells — macrophages — find and destroy altered cells. But cancer cells have various survival strategies. They use sophisticated proteins such as PD-L1, CD47 and CD24 which, once attached to the cell surface, send a "do not attack me" signal.⁷ Macrophages receiving this signal do not attack the altered cells, believing them to be healthy — a kind of cloak of invisibility for cancer cells. Blocking these signals is the basis of some anticancer therapies.⁸ Natural immunoregulators such as Lentinan are known to help block this cancer-cell signal,⁹ making it easier for immune cells to detect the altered cells.

Lentinan — a polysaccharide of Lentinula edodes

From a medical standpoint, Lentinula edodes (the shiitake mushroom) is a "heavyweight" mushroom that combats many health disorders. Used for thousands of years in Eastern medicine, it contains unique substances. One of them is the polysaccharide Lentinan, which has antibacterial, antimicrobial, antiviral, anticancer and immune-stimulating properties.

How does Lentinan work?

Lentinan binds to the surface of lymphocytes, which activates macrophages, T-helper cells and NK cells (natural killer cells). It increases the production of antibodies, including interleukins (IL-2) and interferon (IFN-γ). This triggers the attack on foreign bodies, bacteria, viruses or altered cells. The activity and interaction of these cells is what we call the immune system. Research also shows that the compounds of this remarkable mushroom are effective in protecting against the side effects of radiotherapy and chemotherapy.

Is taking Lentinan "alternative" (non-conventional) medicine?

In some countries, unfortunately, yes. But in some states — even highly developed ones like Japan — it has long ceased to be alternative medicine. In Japan, the active compounds extracted from Lentinula edodes are prescribed in cancer cases, used before, during and after chemo/radiotherapy, because they slow tumour growth and spread and reduce the likelihood of recurrence. In fact, in Japan, polysaccharide-based supplements are leading preparations prescribed in cancer treatment.

When is Lentinan used?

Because Lentinan stimulates and strengthens the immune system, this polysaccharide is used for a vast range of ailments. The person who contributed most to today's enormous interest in the active compounds of Lentinula edodes was the Japanese Ph.D. Dr. Kisaku Mori. As early as 1936 he founded the Mushroom Research Institute in Tokyo. Until his death, Dr. Mori worked with scientists from around the world, studying the medicinal properties of polysaccharides. Through years of research on the human body, he discovered that this active compound is effective for a very long list of diseases — showing antiviral, antibacterial and antitumour properties.

What else to take?

Antioxidants. A study of antioxidant use during and after chemotherapy, comparing 93 clinical trials,¹⁰ found that in 70% of cases chemotherapy effectiveness increased, in 88% of cases antioxidant use eased the toxicity caused by chemotherapy, and in 63% of cases patient survival time was extended. The strongest known natural antioxidant is astaxanthin. Make sure astaxanthin accompanies Lentinan — which is exactly why a formula combining several mushroom extracts with an antioxidant (astaxanthin) is more effective than single ingredients.