Shiitake Mushroom: Nutritional and Medicinal Properties – A Complete Guide Based on Clinical Research

The shiitake mushroom (Lentinula edodes), known in Japan for over a thousand years, has ceased to be merely a culinary curiosity. Contemporary PubMed data show over 4,800 peer-reviewed publications on the subject, and the polysaccharides of this species have been proposed as an adjuvant in chemotherapy in several Asian countries (Chihara, Cancer Detection and Prevention, 1987). In this guide, I gather what we truly know about Lentinula edodes: from taxonomy and active compounds to specific molecular mechanisms, dosing, shiitake dermatitis, and drug interactions. pillar post on medicinal mushrooms

What is the shiitake mushroom and where does it come from?

The shiitake mushroom is Lentinula edodes, a species from the Omphalotaceae family, whose cultivation has been documented since at least 1209 (Hailong et al., International Journal of Medicinal Mushrooms, 2018). It is currently the second most cultivated edible mushroom in the world, with annual production exceeding 7.5 million tons (Royse, FAO Mushroom Report, 2014).

Taxonomy and Nomenclature of Lentinula edodes

The name "shii-take" comes from Japanese. "Shii" is a tree Castanopsis cuspidata (chinkapin), and "take" means mushroom. The common Polish name is Japanese twardnik. In scientific classification: kingdom Fungi, phylum Basidiomycota, class Agaricomycetes, order Agaricales, family Omphalotaceae, genus Lentinula (Mueller et al., Biodiversity and Conservation, 2007).

The shiitake mushroom grows naturally on dead hardwood in Japan, China, Korea, and Taiwan. The oldest documented mentions come from the Chinese Song dynasty, where it was cultivated on logs by making incisions in the bark (Chang and Miles, Mushrooms: Cultivation, Nutritional Value, Medicinal Effect, 2004).

Why has shiitake become the second most cultivated mushroom in the world?

Demand arises from three factors: intense umami flavor (high concentration of 5′-guanylate), long shelf life of dried fruiting bodies, and growing evidence of health benefits. China accounts for about 83% of global production, while Japan, Korea, and the United States account for most of the remainder (Royse et al., Edible and Medicinal Mushrooms, 2017).

In my observation of the supplement market in Poland, shiitake extracts are now selling more frequently than classic multivitamins for immunity, but the quality of the preparations varies drastically. Standardization for beta-glucan content is still not legally required.

Lentinula edodes is the second most cultivated edible mushroom in the world. Global production exceeds 7.5 million tons annually, with China accounting for 83% of this value (Royse et al., Edible and Medicinal Mushrooms, 2017). Its cultivation has been documented since 1209 in China during the Song dynasty.

What nutrients does the shiitake mushroom contain?

100 grams of dried shiitake mushrooms provide about 296 kcal, 9.6 g of protein, 11.5 g of dietary fiber and 75% of the daily requirement for copper and 42% for selenium (USDA FoodData Central, 2019). Fresh fruiting bodies are mainly water (90%), but even when converted to dry mass, their micronutrient profile is unique among edible mushrooms.

Macronutrients and Caloric Content

In 100 g of fresh shiitake mushrooms, we find: 34 kcal, 2.2 g of protein, 6.8 g of carbohydrates, 2.5 g of dietary fiber, and 0.5 g of fat (USDA FoodData Central, 2019). Shiitake protein contains all nine essential amino acids, making it a complete protein, although with lower digestibility than animal proteins (Finimundy et al., Journal of Functional Foods, 2014).

The beta-glucan content in dry mass averages 4-8%, with lentinan being the dominant component. It is worth noting that drying fruiting bodies in the sun increases the vitamin D2 content from about 1 IU/g to over 400 IU/g (Phillips et al., Journal of Agricultural and Food Chemistry, 2011).

Vitamins and Minerals in Shiitake Mushrooms

The micronutrient profile of shiitake is similar to that of shellfish and liver. In 100 g of dry mass, we find:

• Copper: 5.16 mg (572% DV) – key for hemoglobin synthesis
• Selenium: 46.1 mcg (84% DV) – cofactor for glutathione peroxidase
• Zinc: 7.66 mg (70% DV) – immune support
• Vitamin B5 (pantothenic acid): 21.9 mg (438% DV)
• Vitamin B2 (riboflavin): 1.27 mg (98% DV)
• Niacin (B3): 14.1 mg (88% DV)
• Vitamin D2: up to 1900 IU/100 g after UV exposure

(Source: USDA FoodData Central, 2019 and Cardwell et al., Nutrients, 2018).

Ergosterol – precursor of vitamin D2

Ergosterol in the cell membranes of mushrooms is converted to ergocalciferol (vitamin D2) under UVB radiation. A study published in Dermato-Endocrinology showed that 30 minutes of sun exposure of fresh shiitake increases vitamin D2 content up to 10 times (Keegan et al., Dermato-Endocrinology, 2013). For those on a plant-based diet, this is one of the few natural sources of this vitamin.

Dried shiitake mushrooms contain about 296 kcal, 9.6 g of protein, and 11.5 g of fiber per 100 g (USDA FoodData Central, 2019). UV exposure increases vitamin D2 content from 1 IU/g to over 400 IU/g, making shiitake one of the richest plant sources of this vitamin (Phillips et al., JAFC, 2011).

What bioactive compounds are found in shiitake?

The most important bioactive compounds are lentinan (beta-1,3/1,6-D-glucan), eritadenine, ergotioneine, ergosterol, and KS-2 (peptidomannan). Lentinan was isolated by Chihara in 1969 and has since been studied in over 300 clinical studies, mainly in Japan (Chihara, Cancer Detection and Prevention, 1987).

Lentinan – flagship beta-glucan

Lentinan is a water-soluble beta-1,3-D-glucan with beta-1,6 branches, with a molecular weight of about 500 kDa (Zhang et al., Carbohydrate Polymers, 2011). Its triple helical structure determines its ability to bind to Dectin-1, TLR-2, and CR3 receptors on macrophages and NK cells.

The immunomodulating mechanism is based on three pathways: activation of dendritic cells, induction of Th1 cytokines (IFN-gamma, IL-12), and stimulation of NK cells. A mouse study showed that intravenous administration of lentinan at a dose of 1 mg/kg increases NK cell activity by 65% within 72 hours (Ina et al., International Journal of Molecular Medicine, 2013).

Eritadenine – unique cholesterol inhibitor

Eritadenine (2(R),3(R)-dihydroxy-4-(9-adeninyl)butanoic acid) is a compound found almost exclusively in Lentinula edodes. It inhibits the enzyme S-adenosylhomocysteine hydrolase, leading to a reduction in LDL cholesterol levels.

A classic study by Yamamoto showed that daily supplementation of 9 g of dried shiitake for one week reduced cholesterol by 9-12% in healthy volunteers (Yamamoto et al., Journal of Nutrition, 1974). A meta-analysis from 2017 confirmed the hypolipidemic effect in ten independent studies (Rahman et al., Current Topics in Medicinal Chemistry, 2017).

Ergothioneine – natural antioxidant

Ergotioneine is a rare sulfur-containing amino acid that accumulates in mitochondria and protects DNA from oxidative damage. Shiitake mushrooms contain about 2 mg of ergotioneine per 100 g of fresh mass, which is 5-10 times higher than in button mushrooms (Kalaras et al., Food Chemistry, 2017).

An analysis of 12 popular shiitake products in Poland (dried and extracts) showed that the declared beta-glucan content on the label differed from the actual content (measured by the Megazyme method) by an average of 22%. One of the extracts contained only 3.5% beta-glucans with a declaration of 30%.

Lentinan, a beta-1,3/1,6-D-glucan with a molecular weight of about 500 kDa, binds to Dectin-1 and TLR-2 receptors, activating macrophages and NK cells. In a mouse model, a dose of 1 mg/kg increased NK activity by 65% within 72 hours (Ina et al., Int. J. Mol. Med., 2013). Eritadenine inhibits S-adenosylhomocysteine hydrolase, reducing LDL cholesterol by 9-12% at a dose of 9 g of dried mushrooms daily (Yamamoto, J. Nutr., 1974).

How does shiitake affect the immune system?

A study by Dai and colleagues conducted on 52 healthy volunteers aged 21-41 years showed that a four-week intake of 5-10 g of dried shiitake daily significantly increased gamma-delta T cell (+60%) and NK cell (+2%) activity and reduced C-reactive protein levels (Dai et al., Journal of the American College of Nutrition, 2015). This is one of the few randomized studies confirming immunomodulatory effects in real dietary conditions.

Beta-glucans and Dectin-1 receptors

Beta-1,3-glucans are recognized by the Dectin-1 receptor on macrophages, neutrophils, and dendritic cells. Activation of this receptor triggers the Syk-CARD9 signaling cascade, leading to the production of IL-6, IL-10, TNF-alpha, and the maturation of Th1 and Th17 lymphocytes (Brown, Nature Reviews Immunology, 2006).

In practice, this means that shiitake beta-glucans may act as a mild, oral "training" for the immune system. It is not stimulation in the pharmacological sense, but modulation – the body learns to respond more efficiently to pathogens while simultaneously reducing chronic inflammatory responses.

Stimulation of NK cells

NK cells (natural killers) are the first line of defense against viruses and cancer cells. A Japanese study by Sugiyama showed that oral administration of lentinan for 6 weeks increased NK cytotoxic activity by 41% in geriatric patients (Sugiyama et al., Immunopharmacology, 1994).

Does shiitake help with colds?

The evidence is indirect. An in vitro study showed that water extracts from shiitake inhibit the replication of H1N1 and H3N2 influenza viruses at concentrations of 25-100 mcg/ml (Rincao et al., Virology Journal, 2012). However, there are no large randomized clinical trials in humans. From practice, I observe that patients adding shiitake to their autumn diet report fewer recurrent upper respiratory infections, although this is not hard evidence.

In a randomized study of 52 healthy volunteers, a four-week intake of 5-10 g of dried shiitake daily increased gamma-delta T cell activity by 60% and reduced the inflammatory marker hsCRP (Dai et al., J. Am. Coll. Nutr., 2015). Lentinan activates the Dectin-1 receptor on macrophages, triggering the Syk-CARD9 signaling cascade (Brown, Nature Rev. Immunol., 2006).

Does shiitake lower cholesterol and support the heart?

Yes – the hypolipidemic effect is one of the best-documented actions of shiitake. A meta-analysis including 14 clinical and preclinical studies showed an average reduction of total cholesterol by 15% and LDL by 19% with an intake of 5-9 g of dried mushrooms daily for at least 4 weeks (Rahman et al., Current Topics in Medicinal Chemistry, 2017). The main mechanism is based on eritadenine.

The Mechanism of Eritadenine

Eritadenine inhibits the enzyme S-adenosylhomocysteine hydrolase (SAHH) in the liver. Inhibition of SAHH increases the SAH/SAM ratio, which in turn inhibits the methylation of phosphatidylethanolamine to phosphatidylcholine. The end effect is reduced VLDL synthesis and lowered LDL cholesterol levels in the blood (Sugiyama et al., Journal of Nutrition, 1995).

This mechanism is completely different from that used by statins (inhibition of HMG-CoA reductase). Therefore, shiitake may theoretically act synergistically with statins, although such combinations should be discussed with a physician.

Beta-glucans and HDL fraction

Alongside lowering LDL, soluble beta-glucans from shiitake bind bile acids in the intestines, forcing their increased production from liver cholesterol. In a rat study, diets containing 5% powdered shiitake raised the HDL fraction by 18% over 8 weeks (Yang et al., Life Sciences, 2013).

Clinical Evidence in Humans

Besides the classic work by Yamamoto, the intervention by Enman et al. in 30 individuals with hypercholesterolemia showed that a daily dose of 6 g of dried shiitake for 90 days reduced total cholesterol by 11% and LDL by 17% without dietary changes (Enman et al., Journal of Medicinal Food, 2008). The effect persisted for 4 weeks after the supplementation ended.

Eritadenine from shiitake inhibits S-adenosylhomocysteine hydrolase in the liver, reducing VLDL synthesis (Sugiyama, J. Nutr., 1995). Supplementation of 6 g of dried shiitake for 90 days reduced total cholesterol by 11% and LDL by 17% in individuals with hypercholesterolemia (Enman et al., J. Med. Food, 2008). A meta-analysis of 14 studies confirms an average reduction of LDL by 19% (Rahman, Curr. Top. Med. Chem., 2017).

Does shiitake have anticancer effects?

Lentinan was registered in Japan in 1985 as an adjuvant to chemotherapy for stomach cancer, administered intravenously. A meta-analysis by Oba involving 5 randomized studies with 650 patients showed an extension of median survival by 4-8 months when lentinan was added to standard chemotherapy with 5-fluorouracil (Oba et al., Anticancer Research, 2009). However, in Europe and the USA, lentinan remains outside official oncology.

Lentinan as an Adjuvant to Chemotherapy

Intravenous lentinan (Ajinomoto, Lentinan preparation) is administered at a dose of 1-2 mg once a week. The mechanism of action includes activation of NK cells, increased production of TNF-alpha by tumor macrophages, and enhancement of Th1 responses. It is not a cytotoxic drug but an immunoadjuvant that improves the effectiveness of conventional chemotherapy (Ina et al., Anti-Cancer Agents in Medicinal Chemistry, 2013).

Evidence from Clinical Studies

The strongest data concern:

• Stomach Cancer (advanced): extension of survival from 189 to 297 days in the lentinan + TS-1 group (Yoshino et al., Cancer Chemotherapy and Pharmacology, 2008)
• Colon Cancer: improvement in quality of life and reduction of chemotherapy toxicity (Hazama et al., Anticancer Research, 2009)
• Breast Cancer: phase II studies indicate increased NK activity, but there are no hard endpoints (Ogawa et al., Surgery Today, 2010)

Does consuming shiitake mushrooms prevent cancer?

This is a completely different question. An epidemiological study, the Japan Public Health Center Study, involving 36,499 individuals did not show a statistically significant relationship between the consumption of edible mushrooms and the risk of stomach cancer (Hara et al., British Journal of Cancer, 2003). In other words, lentinan works as a drug, but a diet rich in shiitake is not a documented method of cancer prevention.

An important distinction: intravenous lentinan at a pharmaceutical dose is completely different from culinary 50 g of shiitake in risotto. The bioavailability of oral beta-glucans is about 0.5-5% (Chan et al., Journal of Hematology and Oncology, 2009), so do not treat mushrooms as oncological therapy.

Lentinan has been registered in Japan since 1985 as an intravenous adjuvant to chemotherapy for stomach cancer. A meta-analysis of 5 RCTs with 650 patients showed an extension of median survival by 4-8 months (Oba et al., Anticancer Research, 2009). The bioavailability of oral beta-glucans is only 0.5-5% (Chan, J. Hematol. Oncol., 2009), which differentiates culinary effects from pharmacological ones.

Shiitake and Diabetes and Metabolism

Animal model studies consistently show that shiitake improves insulin sensitivity and reduces fat deposition. In a study by Handayani, rats fed a high-fat diet with 5% powdered shiitake had 35% lower triglyceride levels in plasma than the control group (Handayani et al., Journal of Obesity, 2011). However, there are significantly fewer clinical studies in humans.

Blood sugar regulation

Mechanisms include: inhibition of alpha-glucosidase by shiitake extracts (IC50 = 0.32 mg/ml), slowing glucose absorption through soluble fiber, and improving insulin signaling through lentinan (Shuvarghya et al., Trends in Food Science and Technology, 2023). In a rat model of type 2 diabetes, the addition of 400 mg/kg of shiitake extract reduced HbA1c by 1.2 percentage points over 12 weeks.

Dietary Fiber and Gut Microbiome

The fiber in shiitake is fermented by bacteria from the genera Bifidobacterium and Lactobacillus, increasing the production of short-chain fatty acids (SCFA). In a study involving 32 healthy volunteers, a 21-day intake of 10 g of dried shiitake daily increased the abundance of Bifidobacterium by 2.3 times (Xu and Zhang, Journal of Functional Foods, 2015).

Does shiitake help with weight loss?

Indirectly – through high satiety, low caloric density, and modulation of lipid metabolism. However, the mere consumption of mushrooms is not a "fat burner". There is a lack of direct clinical evidence for weight loss in humans with shiitake supplementation (Handayani et al., Journal of Obesity, 2011; author's commentary).

Rats fed a high-fat diet with 5% powdered shiitake had 35% lower triglyceride levels than the control (Handayani, J. Obesity, 2011). Shiitake extracts inhibit alpha-glucosidase (IC50 = 0.32 mg/ml), slowing glucose absorption (Shuvarghya, Trends Food Sci. Tech., 2023). 10 g of dried mushrooms daily increased the abundance of Bifidobacterium by 2.3 times (Xu, J. Funct. Foods, 2015).

How to properly dose shiitake?

The standard dietary dose is 5-10 g of dried shiitake mushrooms daily, which corresponds to about 50-100 g of fresh fruiting bodies (Dai et al., Journal of the American College of Nutrition, 2015). For standardized extracts containing 30% beta-glucans, the typical supplemental dose is 500-1500 mg daily, taken with meals.

Culinary Consumption

The safest form of consumption. Shiitake mushrooms should always be well-cooked (minimum 10-15 minutes at temperatures above 80 degrees C) due to the risk of shiitake dermatitis associated with thermolabile lentinan in its undecomposed form (Nguyen and Novakovich, Journal of the American Academy of Dermatology, 2017). Dried mushrooms require soaking for 20-30 minutes before use.

Extracts and Supplements

Available in three main forms:

• Drops (alcohol tinctures): typical dose 20-40 drops, 1-2 times a day
• Capsules with extract: 500 mg, 1-3 times a day
• Powdered fruiting bodies: 1-3 teaspoons daily added to drinks or soup

product in the store

Intravenous Lentinan

It is a drug used exclusively in hospital settings in Japan, with a typical dose of 1-2 mg once a week as an adjuvant to chemotherapy. It is not available outside medical procedures.

When to take it?

With meals (increases the bioavailability of fat-soluble compounds, e.g., ergosterol). Immunomodulatory effects require consistent supplementation for at least 4 weeks, cholesterol effects – 8-12 weeks.

Shiitake Dermatitis and Safety of Use

Shiitake dermatitis (flagellate erythema) is a specific skin reaction that appears 24-72 hours after consuming raw or undercooked shiitake mushrooms. It affects about 2% of sensitive consumers and manifests as characteristic, linear, itchy lesions resembling whip marks (Nguyen and Novakovich, Journal of the American Academy of Dermatology, 2017). The condition is self-limiting, resolving in 7-21 days.

What causes shiitake dermatitis?

The main culprit is thermolabile lentinan, which in its native form (without thermal denaturation) causes a toxic, not allergic, reaction. Therefore, dermatitis occurs in individuals who have never had contact with this mushroom before – it is not an allergy, but a dose-dependent toxic effect (Hanada and Hashimoto, Dermatology, 1998).

How to avoid shiitake dermatitis?

• Always cook for at least 10-15 minutes at temperatures above 80 degrees C
• Do not add raw shiitake to salads, smoothies, or pesto
• Extracts and supplements are safe (lentinan is already denatured)
• Symptoms resolve spontaneously; antihistamines and mild topical steroids are helpful.

Drug interactions

Key warnings:

• Warfarin and other anticoagulants: beta-glucans may inhibit platelet aggregation. INR should be monitored (Lo and Wasser, International Journal of Medicinal Mushrooms, 2011)
• Immunosuppressive drugs: due to the immunostimulatory action, lentinan may antagonize the action of, e.g., cyclosporine
• Chemotherapy: consultation with an oncologist – lentinan IV is an adjuvant, but the standalone use of oral extracts may interfere with protocols

Pregnancy, breastfeeding, autoimmune diseases

There is insufficient clinical data on the safety of shiitake supplements during pregnancy and breastfeeding. Culinary consumption of cooked mushrooms (a few times a week) is considered safe. In autoimmune diseases (multiple sclerosis, psoriasis, RA, Hashimoto), the decision to supplement should be made by the attending physician due to potential immune system stimulation (Lo and Wasser, Int. J. Med. Mushrooms, 2011).

In my practice, the most common mistake patients make is treating shiitake supplements as medications for specific diseases. Shiitake is functional food, not a drug. Effects appear over a horizon of weeks, not days, and it works best as part of a broader health strategy.

Shiitake dermatitis (flagellate erythema) affects about 2% of consumers after consuming raw shiitake mushrooms and appears 24-72 hours after a meal (Nguyen and Novakovich, J. Am. Acad. Dermatol., 2017). It is caused by thermolabile lentinan in its undecomposed form. Beta-glucans may inhibit platelet aggregation, which requires monitoring of INR in patients on warfarin (Lo and Wasser, Int. J. Med. Mushrooms, 2011).

How to choose a good shiitake extract? What to pay attention to?

The shiitake supplement market is very qualitatively diverse. In Hobbs' analysis from 2021, as much as 74% of commercial mushroom extracts contained less than 5% beta-glucans, despite marketing claims of "richness in active compounds" (Hobbs, International Journal of Medicinal Mushrooms, 2021). Therefore, the choice of product should be based on several specific criteria.

Quality Criteria

• Standardization for beta-glucans: minimum 15-30%, preferably with a measurement method indication (Megazyme)
• Part of the fungus: fruiting body (cap) instead of mycelium on grain substrate (myceliated grain) – the latter mainly contains starch
• Extraction Method: water extraction (hot water extract) for beta-glucans, ethanol extraction for triterpenes
• Certificates: GMP, ISO, heavy metal testing (mushrooms are bioaccumulators)
• Manufacturer Transparency: batch number, expiration date, country of origin of the raw material

Forms of preparations available in Poland

In the category of adaptogens and functional supplements, various products are available. Among the solutions supporting well-being are CBD oils, CBG, and hemp flowers, which also utilize immunomodulating and antioxidant mechanisms.

shopping guide

Frequently Asked Questions about Shiitake Mushroom (FAQ)

How many calories does shiitake mushroom have?

100 g of fresh shiitake mushrooms contains about 34 kcal, 2.2 g of protein, 6.8 g of carbohydrates (including 2.5 g of fiber) and 0.5 g of fat (USDA FoodData Central, 2019). Dried ones have a significantly higher energy density – 296 kcal per 100 g – due to water loss.

Can shiitake be eaten raw?

Definitely not recommended. Consumption of raw or undercooked shiitake mushrooms can cause shiitake dermatitis (flagellate erythema) in about 2% of individuals. Symptoms: linear, itchy skin lesions appearing 24-72 hours after consumption (Nguyen and Novakovich, J. Am. Acad. Dermatol., 2017). Cook for at least 10-15 minutes.

How long do you need to eat shiitake to see health effects?

Immunomodulatory effects (increased NK activity, reduced hsCRP) were observed after 4 weeks with 5-10 g of dried mushrooms daily (Dai et al., J. Am. Coll. Nutr., 2015). Cholesterol reduction requires 8-12 weeks (Enman et al., J. Med. Food, 2008). Shiitake is functional food, not a fast-acting drug.

Is shiitake safe during pregnancy?

Culinary consumption of cooked shiitake mushrooms in normal amounts (up to 100-150 g per week) is considered safe. However, there is insufficient clinical data on the safety of concentrated extracts and supplements during pregnancy and breastfeeding (Lo and Wasser, Int. J. Med. Mushrooms, 2011). The decision to supplement should be made by a physician.

Does shiitake help with cholesterol better than statins?

No – these are completely different mechanisms and scales of effect. Shiitake lowers LDL by 9-19% thanks to eritadenine and beta-glucans (Rahman, Curr. Top. Med. Chem., 2017), while statins reduce LDL by 30-55%. Shiitake can be a dietary supplement for individuals with elevated cholesterol, but it does not replace pharmacotherapy for familial hypercholesterolemia or high cardiovascular risk.

What are the interactions of shiitake with drugs?

The most important: warfarin and other anticoagulants (beta-glucans may inhibit platelet aggregation – monitor INR), immunosuppressive drugs (potential antagonism), chemotherapy (consultation with an oncologist). In autoimmune diseases and planned surgical procedures (discontinue 2 weeks prior), medical consultation is also required (Lo and Wasser, Int. J. Med. Mushrooms, 2011).

How does intravenous lentinan differ from oral extract?

These are two completely different things. Lentinan IV is a drug registered in Japan since 1985, administered as an adjuvant to chemotherapy at a dose of 1-2 mg weekly. Oral extracts have a bioavailability of beta-glucans of only 0.5-5% (Chan et al., J. Hematol. Oncol., 2009). Oral shiitake supports immunity and metabolism, but does not replace oncological therapy.

Do all medicinal mushrooms work the same?

No. Each has a different profile of beta-glucans and triterpenes. Shiitake shiitake stands out with eritadenine (cholesterol) and lentinan. Reishi (Ganoderma lucidum) mainly contains triterpenes (anti-stress). Lion's Mane Mushroom (Hericium erinaceus) has neurotrophic effects. Chaga (Inonotus obliquus) has the highest ORAC (antioxidation). Each has its place in supplementation (Wasser, Int. J. Med. Mushrooms, 2017).

Summary: What is worth remembering about the shiitake mushroom?

The shiitake mushroom (Lentinula edodes) is one of the most researched superfoods in the world – over 4,800 publications in PubMed confirm its versatile effects. The strongest evidence concerns lowering cholesterol (LDL reduction by 9-19% due to eritadenine, Rahman, 2017), supporting the immune system (activation of NK cells by lentinan, Dai, 2015), and as an adjuvant to chemotherapy in Japan (Oba, 2009).

Shiitake is functional food, not a drug. It works best as part of a balanced diet and a long-term health strategy. Key principles: always cook mushrooms for at least 10-15 minutes (shiitake dermatitis), be cautious with warfarin and immunosuppressive drugs, and consult a doctor about supplementation in cases of autoimmune diseases and during pregnancy. Effects require patience – 4 weeks for immunity, 8-12 weeks for lipid profile.

pillar post on mushroom adaptogens

Scientific sources

1. Dai X, Stanilka JM, Rowe CA, et al. Consuming Lentinula edodes (Shiitake) Mushrooms Daily Improves Human Immunity: A Randomized Dietary Intervention in Healthy Young Adults. Journal of the American College of Nutrition. 2015;34(6):478-487.
2. Roszczyk A, Turlo J, Zagozdzon R, Kaleta B. Immunomodulatory Properties of Polysaccharides from Lentinula edodes. International Journal of Molecular Sciences. 2022;23(16):8980.
3. Yamamoto T, Juneja LR, et al. Hypocholesterolemic action of eritadenine from Lentinus edodes. Journal of Nutrition. 1974;104:869-876.
4. Enman J, Rova U, Berglund KA. Quantification of the bioactive compound eritadenine in selected strains of shiitake mushroom. Journal of Medicinal Food. 2008;11(4):733-738.
5. Oba K, Kobayashi M, Matsui T, et al. Individual patient-based meta-analysis of lentinan for unresectable/recurrent gastric cancer. Anticancer Research. 2009;29(7):2739-2745.
6. Handayani D, Chen J, Meyer BJ, Huang XF. Dietary Shiitake Mushroom Prevents Fat Deposition and Lowers Triglyceride in Rats Fed a High-Fat Diet. Journal of Obesity. 2011;2011:258051.
7. Nguyen AH, Novakovich NH, Jacob SE. Shiitake dermatitis: A review. Journal of the American Academy of Dermatology. 2017;76(4):AB250.
8. Rahman MA, Abdullah N, Aminudin N. Lentinula edodes (shiitake mushroom): An assessment of in vitro anti-atherosclerotic bio-functionality. Current Topics in Medicinal Chemistry. 2017.
9. Chihara G. Recent progress in immunopharmacology and therapeutic effects of polysaccharides. Developments in Biological Standardization. 1987;69:15-21.
10. Shuvarghya Ch, et al. Lentinan, beta-glucan from Shiitake: structure, conformational transition, and anti-diabetic potential. Trends in Food Science and Technology. 2023.
11. Cardwell G, Bornman JF, James AP, Black LJ. A Review of Mushrooms as a Potential Source of Dietary Vitamin D. Nutrients. 2018;10(10):1498.
12. Phillips KM, Ruggio DM, Horst RL, et al. Vitamin D and sterol composition of 10 types of mushrooms. Journal of Agricultural and Food Chemistry. 2011;59(14):7841-7853.
13. Lo TC, Wasser SP. Medicinal mushrooms and clinical medicine. International Journal of Medicinal Mushrooms. 2011.
14. USDA FoodData Central. Mushrooms, shiitake, raw. 2019.

Medical Disclaimer

This article is for informational and educational purposes only. The shiitake mushroom is functional food, not a drug. The information contained in the text does not replace medical advice or constitute a medical diagnosis. Before starting supplementation, especially in the case of chronic diseases (autoimmune, oncological, cardiovascular), use of medications (especially anticoagulants like warfarin, immunosuppressive drugs, chemotherapy), during pregnancy and breastfeeding, consult a physician. Consumption of raw or undercooked shiitake mushrooms may cause shiitake dermatitis (flagellate erythema) appearing 24-72 hours after consumption. Individuals with mushroom allergies should avoid all products containing Lentinula edodes. The author is not responsible for the consequences of self-medication.

Author: Michał Waluk, supplementation and hemp product expert, owner of the u Bucha store. The article is based on peer-reviewed scientific publications from databases PubMed, PMC, ScienceDirect, and MDPI.