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Shiitake are the most consumed of all the healing mushrooms

Shiitake mushroom

Lentinula edodes Marasmiaceae (order Agaricales)

Shiitake are a coveted fixture of traditional East Asian food therapy and herbalism. This ancient mushroom, revered as a tonic, is now a growing staple in kitchens the world over as well as a valuable source of nutritional supplements and chemotherapy adjuvant therapy owing to its many potential health benefits, notably for cancer care, cholesterol control and immunity.

Sustainability Status

Sustainability status

Not currently on risk lists but complete data may be missing on the status of the species. Read more about our sustainability guide.

Key benefits
  • Cancer
  • Cholesterol
  • Hypertension
  • Anti-viral
  • Immune support
  • How does it feel?

    Shiitake is a supremely tasty fungus with an earthy, rich umami flavour and a velvety, meaty texture, making it a great meat substitute.

  • What can I use it for?

    Shiitaki fungi (Lentinula edodes)
    Shiitaki fungi (Lentinula edodes)

    Shiitake is a great addition to any diet, not in the least to vegans and vegetarians, as they have a great nutritional profile, being low in fat and rich in protein, fibre, vitamins and minerals. Notably, they have high levels of B vitamins and vitamin D2, supporting adrenal and cognitive function, bone and heart health. They are also one of the richest dietary sources of copper, an essential nutrient involved in red blood cell formation, bone health, cardiovascular, immune and nervous system functioning as well as collagen production.  

    Like many medicinal fungi, shiitake extracts have been widely studied and applied to cancer care for decades not only to promote cancer cell death and inhibit their proliferation but also as an adjuvant to enhance the efficacy of conventional therapies, reduce side effects and support the immune system, thereby potentially reducing recurrence (1).  

    Indeed, immune support is another of shiitake’s primary health benefits. Observed immunomodulatory effects alongside antiviral and antimicrobial properties make shiitake tasty little immune powerhouses that are easily incorporated into one’s daily life with potential benefits for sufferers of conditions such as HIV, candida and hepatitis to name but a few (2).    

    They have also displayed an ability to influence the gut microbiota, blood lipid levels and blood pressure and may, therefore, also be a useful dietary and herbal allay for those suffering with poor digestion, high cholesterol and hypertension. 

  • Into the heart of shiitake mushroom

    Dried shiitake mushrooms (Lentinula edodes)
    Dried shiitake mushrooms (Lentinula edodes)

    Rich in polysaccharides (even as compared to other edible mushrooms (2)) and beneficial bioactive compounds, shiitake has been studied extensively, particularly in relation to its perceived anti-cancer and immune-modulating abilities. Indeed, Lentinan, a polysaccharide extract from shiitake mycelium, was the earliest and most thoroughly studied of all the edible fungi polysaccharides and has been used clinically as an anticancer adjuvant therapy in Japan and China since the 1980s (4). 

    In traditional East Asian medicine, shiitake is regarded as energetically sweet and neutral making it a gentle, nourishing tonic for the body that lend itself to regular consumption and has been used in traditional East Asian medicine for thousands of years to strengthen weakness, in particular of the Spleen and Stomach; our digestive centre. In doing so, they not only help to address digestive deficiencies manifesting in symptoms such as poor appetite and bloating, but also promote the flourishing of our qi (energy), blood and wei qi (immunity) whose vigour is firmly rooted in sound digestion.

  • Traditional uses

    Lentinula edodes, known in Japan and more widely as shiitake (shii meaning the Castanopsis cuspidata tree and take meaning mushroom) and ‘fragrant mushroom’ (xiang gu) in China has an extensive history in East Asia where it has been used in food and traditional medicine as a qi tonic to bolster strength, digestion, circulation and immunity for millennia. Many traditional sources also hold that shiitake supports fluid metabolism, reducing dampness and phlegm in the body.

  • Traditional actions

  • Traditional energetic actions

    Herbal energetics are the descriptions Herbalists have given to plants, mushrooms, lichens, foods, and some minerals based on the direct experience of how they taste, feel, and work in the body. All traditional health systems use these principles to explain how the environment we live in and absorb, impacts our health. Find out more about traditional energetic actions in our article “An introduction to herbal energetics“.

  • What practitioners say

    Fresh shiitake (Lentinula edodes)
    Fresh shiitake (Lentinula edodes)

    The following are the main extracts and bioactive compounds of shiitake:

    Lentinan: A polysaccharide extract derived from shiitake mycelia. Beta-glucans are its major active component and it is known for its immunostimulatory and antineoplastic (anti-cancer) effects. It is licensed for clinical use for treating stomach cancer in Japan and has been used as a chemotherapy adjuvant therapy in China and Japan for decades. Lentinan is also used in the treatment of viruses such as HIV and hepatitis. 

    LEM (Lentinula edodes mycelia extract): a shiitake mycelia crude, hot water extracted powder with potential immunomodulatory and antitumor properties. 

    AHCC (active hexose-correlated compound): a proprietary alpha-glucan extract from sources including shiitake mycelia and a popular supplement for cancer patients in Japan since 1987, AHCC is also taken for the treatment of HIV, HPV and impaired liver function.  

    Eritadenine: A chemical compound from shiitake fruiting bodies and mycelia with demonstrated lipid-lowering effects, it has been found to inhibit an enzyme involved in cholesterol production. 

    Ergothioneine: An amino acid derived from a small selection of natural sources including shiitake, with powerful antioxidant properties. 

    In addition to the regular consumption of the shiitake mushroom fruiting body, the following potential benefits (elucidated from just some of the many existing pre-clinical and clinical studies – some of which small and need further exploration) were gained from the above extracts and compounds (see Research below for individual study details).

    Cancer: Shiitake displays an ability to inhibit the proliferation of tumour cells (5,6) and induce cancer cell apoptosis (cell death) (5). When given alongside chemotherapy it may enhance its effects, (7) improve quality of life, (8,1) increase immune function, (1,7,8) reduce neutrophil-related side effects (where low white blood cell counts are a common side-effect of chemotherapy) and the resultant use of Granulocyte-colony stimulating factor (G-CSF) (the typical treatment for neutropenia, that comes with its own side effects) (9).

    Immune: Shiitake has been seen to increase immune function generally. (1,7,8,10) In particular, it may increase T-cell (including Natural Killer cell (NKC)) numbers and activity, (8,10,11) influence the function of innate immune cells such as monocytes, macrophages and DCs (dendritic cells; messenger cells between the innate and adaptive immune systems), (12) alter cytokine (immune messenger protein) expression, lower inflammation levels, increase secretory IgA (SIgA) (the primary antibodies found in the gut) and, therefore, intestinal immunity (11) and increase IFN-y (an important cytokine involved in activating immune responses) (13). 

    Other: Shiitake may also reduce blood pressure (14) and triglycerides (blood lipids), (14-16) inhibit weight gain, (16) reduce oxidative stress biomarkers and increase the body’s main endogenous (self-made) antioxidant, (15) influence gut microbiota, (17) exhibit selective antibacterial effects (18) and possess antiviral effects (19).

  • Research

    Shiitake mushrooms dried (Lentinula edodes)
    Shiitake mushrooms dried (Lentinula edodes)


    When treating chronic, complex or serious conditions it is always best to approach a qualified integrative healthcare practitioner/ specialist. There are many nuances when working with herbs and serious conditions and sometimes one can unwittingly exacerbate issues. A qualified herbalist and integrative practitioner will be able to discern and guide you safely. You can learn more about herbal approaches for caring for cancer in our podcast with herbal oncologist Chanchal Cabrera.  Also, take a look at our resource page “Where to find a herbalist” and see our article Mushrooms for cancer care.

     In vitro studies 

    An early study using an ethyl acetate fraction of shiitake with human breast and blood cancer cell lines found that the fraction not only inhibited the proliferation of tumour cells but also induced apoptosis (cell death), suggesting possible anti-tumour capabilities (5).

    A subsequent study using aqueous extracts of both shiitake fruiting body and mycelium with human breast cancer cell lines also observed a direct and significant antiproliferative effect (6). 

    Human clinical trials

    A very small study of 7 breast or gastrointestinal cancer patients receiving chemotherapy post-surgery found that LEM (Lentinula edodes mycelia extract) alongside chemotherapy produced no adverse events, improved quality of life scores, natural killer cell activity and immune function as compared to a prior round of chemotherapy where they received chemotherapy alone (8).

    A larger retrospective study of 41 women receiving chemotherapy for breast cancer found that 3g of AHCC (active hexose-correlated compound) daily resulted in significantly less neutrophil-related side effects from chemotherapy as compared to the control group and, subsequently, a reduction in the use of Granulocyte-colony stimulating factor (G-CSF). Neutropenia (low white blood cell count) is a common side effect of chemotherapy and G-CSF is the typical treatment for this but carries with it its own side effects. (9)   

    A 2017 placebo-controlled randomised double-blind study of 47 women with early-stage breast cancer receiving postoperative anthracycline-based chemotherapy gave 1800mg LEM in tablet form per day alongside 5HT3 receptor antagonists (commonly prescribed as supportive therapy to alleviate chemotherapy-induced nausea and vomiting) to the experimental group for the duration of two courses (6 weeks) of chemotherapy. The placebo group, receiving no LEM, recorded decreased quality of life and lowered immune function. Those receiving LEM adjuvantly reported no reduction in quality of life and immune function was maintained. (8)

    A similar study involving 50 oesophageal cancer patients examined the use of 1mg diluted Lentinan per day alongside chemotherapy. After two rounds of chemotherapy, clinical efficacy (remission versus progression) was significantly greater in the experimental group along with a relative increase in immune function. Both groups showed an improvement in general condition, signs and symptoms and quality of life scores after the two rounds of treatment, however improvement was significantly greater in the group receiving LEM (7).   

    Fresh and dried Shiitake (Lentinula edodes)
    Fresh and dried Shiitake (Lentinula edodes)



    A 2019 review of 20 clinical and pre-clinical studies concluded that AHCC has numerous immunologic effects, in particular on T-cells and natural killer (NK) cells whose function and numbers may be influenced by the compound. It is also believed to influence the function of innate immune cells such as monocytes, macrophages and DCs (dendritic cells; messenger cells between the innate and adaptive immune systems), again promoting T cell function, with promising biological effects on tumours, inflammation and infections. (10)    

    A subsequent, 2022 review of clinical and pre-clinical studies exploring the immunomodulatory effects of shiitake also concluded that, from the 12 human trials reviewed, shiitake polysaccharides appear to have a strong immunologic influence on humans, however the nature of these effects seems to differ according to the extraction method used and the source (fruiting body or mycelium) with Lentinan (extracted from the fruiting body) being immunostimulatory and polysaccharides derived from the mycelium yielding selective immunosuppressive effects (20).

    Human clinical trials

    A parallel group study involving 52 healthy participants consuming 5 or 10g of whole dried shiitake mushrooms daily for four weeks found that shiitake consumption both increased specific T-cells (Gamma-delta and Natural Killer) and their function, significantly altered cytokine (immune messenger protein) expression and lowered inflammation levels and increased secretory IgA (SIgA) (the primary antibodies found in the gut) and, therefore, intestinal immunity (11).

    A randomised, double-blind, placebo-controlled trial involving 80 healthy participants explored the immune effects of daily consumption of 18g of rice bran fermented with shiitake (rice bran exo-biopolymer (RBEP)) in capsule form over eight weeks. They found RBEP supplementation increased IFN-y (an important cytokine involved in activating immune responses) secretion with no adverse effects. (13)

    A smaller randomised control trial (RCT) looking in to the effects of 3g per day of AHCC on DCs (dendritic cells) in 21 healthy participants over four weeks found a significant increase in DCs in the experimental group as compared to baseline and the control group along with an increase in function of DC1s (dendritic cells involved in acquired immunity). (12)

    Obesity/ Cholesterol/ Hypertension 

    A 2021 double-blind RCT involving 68 participants with borderline high cholesterol investigated the effects of daily consumption of a shiitake food bar for 66 days, at the end of which the intervention group showed a 10% reduction in triglycerides (blood lipids) and improved oxidative stress biomarkers including an increase in the body’s main endogenous antioxidant. (15)

    Similarly, animal studies using shiitake fruiting body powder displayed beneficial effects on blood lipid levels (14,16), weight gain (16) and hypertension. (14)  

    Gut health/ Cholesterol

    A 2021 double-blind RCT involving 52 participants with high cholesterol explored the cholesterol-lowering and immune and gut microbiota modulating effects of a shiitake-derived beta-D-glucan-enriched mixture where 3.5g of beta-D-glucans were consumed daily over eight weeks. It was found that the mixture altered the colonic microbiota of the test subjects with several types of microbial organisms affected being directly linked (positively and negatively) with some of the biomarkers associated with the metabolism of cholesterol (17).


    An in vitro study using human saliva investigating the antimicrobial effects of a shiitake extract on gingivitis (gum inflammation) as compared to the leading gingivitis mouthwash established that not only did the shiitake extract lower bacterial numbers but it did so without impacting the microbial species associated with oral health in contrast to the mouthwash which lowered numbers of all bacteria, both good and bad (18).

    Another in vitro study exploring the antiviral effects of both aqueous and ethanol extracts of shiitake fruiting body as well as shiitake polysaccharide (LeP) from the fruiting body found they all inhibited the replication of poliovirus type 1 and bovine herpes virus type 1 in the early stages of infection (19).

  • Did you know?

    Reverence of the shiitake mushroom in China is such that an annual day of feasting celebrates the life of Wu San Kwung, believed to be the first to cultivate this coveted mushroom in around 1000CE, with temples across the country also dedicated to his memory (21).

Additional information

  • Botanical description

    Shiitake are small to medium brown-capped fungi with white or creamy gills on the underside and thin white stems. They grow in clusters with caps of 10-20cm in diameter.

  • Common names

    • Shiitake (Japanese: “Castonopsis mushroom”)
    • Xiang gu (Chinese: “fragrant mushroom”)
    • Dong gu (Chinese: “Winter mushroom”)
    • Hua gu (Chinese: “flower mushroom)
    • Chinese black mushroom
    • Black Forest mushroom
    • Golden Oak mushroom
  • Safety

    Consumption has been linked to a rare form of dermatitis, known as shiitake dermatitis, possibly owing to its lentinan content. It is commonly, but not exclusively, linked to cases where the mushroom has been eaten raw or undercooked. Research into its safe use during pregnancy or when breastfeeding is lacking.

  • Interactions

    May interact with Gabapentin, an anticonvulsant drug commonly used for epilepsy and neuropathy, however, this may not have “clinically important” ramifications (22).

  • Contraindications

    Mushroom allergy

  • Preparation

    • Raw or cooked fresh or dried fruiting body
    • Herbal teas
    • Water extracts
    • Ethanol extracts
    • Ethyl acetate extracts
    • Freeze-dried extracts
    • Oil extracts
    • Powders
    • Tablets
    • Capsules
  • Dosage

    • 9g day dried fruit body for cholesterol control
    • 2-6g day polysaccharide extract for immune support (2)
    • Most human studies for AHCC give 3g per day
  • Plant parts used

    Fruiting body and mycelium

  • Constituents

    • Polysaccharides (beta-glucans (lentinan), alpha-glucans)
    • Glycoproteins
    • Phenols
    • Steroids
    • Terpenoids
    • Nucleotides
    • Amino acids (including arginine, histidine, leucine, isoleucine, lysine, methionine, phenylalanine, threonine, valine, and tryptophan)
    • Vitamins (including B1, B2, B12, C, D, E)
    • Minerals (including calcium, potassium, magnesium, potassium, copper and zinc)
Shiitake (Lentinula edodes)
  • Habitat

    Grows in the wild in East Asia in warm, humid environments on a range of fallen deciduous hardwood trees. Cultivated globally.

  • Sustainability

    The International Union for Conservation of Nature (IUCN) Red List of Threatened Species does not feature the shiitake mushroom. Issues around shiitake sustainability appear to be from the sheer enormity of the scale of its cultivation globally and the potential energy consumption and waste that artificial commercial production inevitably produces:

    “In the author’s experience, for every 900 g of shiitake mushroom yield, ~15 g of HDPE bags [non-biodegradable, disposable high-density polyethylene bags] become waste. This means that if the global production of shiitake mushroom is 10 million tons based on past literature [from 2017], then more than 160,000 tons of waste is produced annually.” (23 p5)

    Chinese shiitake log cultivation is a more eco-friendly means of production, however, the sustainable sourcing of these trees must also be considered. “Forest farming” shiitake is another ecological alternative and is already extensive in Japan (23).

  • Quality control

    Look for supplements with high levels of polysaccharides, ideally a minimum of 15% beta-glucans, and without fillers or starches.

  • How to grow

    Best grown on sawdust pellets or deciduous hardwood logs (especially oak) in the spring. Logs inoculated with plug spawns (inoculated wooden dowels) are an easy option for beginners with great yield potential. Hammer plugs in to holes drilled in clean, relatively freshly cut logs then cover with wax. Place in a shady position, raised from the ground and water weekly or bi-weekly if in a dry climate. Incubation takes between 6-12 months. After this time, submerge the log in water for 24 hours then stand in the shade. Mushrooms will begin to grow within 2 weeks and logs must be watered daily. Logs may last between 4-6 years with forced flushes of mushrooms every 5-6 weeks after repeating the soaking process (24).

  • Recipe

    Healing herbal shiitake mushroom soup recipe
    Healing herbal shiitake mushroom soup

    This delicious mushroom broth recipe shares how to make a delicious shiitake soup which incorporates other medicinal herbs.


    • 3 strips small kombu
    • 2 sage leafs
    • 2 dried shiitake mushrooms
    • 1⁄4 tsp sesame oil
    • 1.5l water
    • 1 tsp tamari
    • 1 clove of garlic
    • 1 tsp ginger, grated
    • Pinch of pepper


    1. Soak the shitake mushroom in 1.5l of water for at least an hour or until the inside is fully rehydrated.
    2. Keep the soaking water for cooking. Add tamari and a pinch of pepper. Stir well.
    3. In a pot, add the shitake water the shiitake was soaked in, kombu, shitake mushrooms, grated garlic and ginger,
    4. Turn the heat on high and bring to a boil, then turn down the heat to simmer for about 20 mins.
    5. Slice the kombu thinly into strips when it is soft and cooked through, then put it back in the soup.
    6. Turn the heat off.
    7. Finely slice the sage leaves into small strips and add them on top of the soup as a garnish.
    8. Let it infuse for 10 minutes.
    9. Serve.
  • References

    1. Nagashima Y, Yoshino S, Yamamoto S, et al. Lentinula edodes mycelia extract plus adjuvant chemotherapy for breast cancer patients: Results of a randomized study on host quality of life and immune function improvement. Mol Clin Oncol.2017;7:359–366.
    2. Powell M. Medicinal Mushrooms: A Clinical Guide 2nd ed. Dorset: Caric Press, 2014.
    3. Yu Q et al. Analysis of Nutritional Composition in 23 Kinds of Edible Fungi. Journal of Food Quality. 2020; 8821315. doi:10.1155/2020/8821315
    4. Zhang M et al. Mushroom polysaccharide lentinan for treating different types of cancers: A review of 12 years clinical studies in China. Prog Mol Biol Transl Sci. 2019;163:297-328. doi: 10.1016/bs.pmbts.2019.02.013. Epub 2019 Apr 4. PMID: 31030752.
    5. Fang N et al. Inhibition of growth and induction of apoptosis in human cancer cell lines by an ethyl acetate fraction from shiitake mushrooms. J Altern Complement Med. 2006 Mar;12(2):125-32. doi: 10.1089/acm.2006.12.125. PMID: 16566671.
    6. Israilides C et al. In vitro cytostatic and immunomodulatory properties of the medicinal mushroom Lentinula edodes. Phytomedicine. 2008; 6–7(15):512. doi.org/10.1016/j.phymed.2007.11.029.
    7. Wang JL et al. Combination therapy with lentinan improves outcomes in patients with oesophagal carcinoma. Mol Med Rep. 2012 Mar;5(3):745-8. doi: 10.3892/mmr.2011.718. Epub 2011 Dec 19. PMID: 22200763.
    8. Yoshiyuki Y et al. Efficacy and Safety of Orally Administered Lentinula edodes Mycelia Extract for Patients Undergoing Cancer Chemotherapy: A Pilot Study. The American Journal of Chinese Medicine. 2011;(39)3:451-459. doi: 10.1142/S0192415X11008956.
    9. Hangai S et al. Effect of active hexose-correlated compound in women receiving adjuvant chemotherapy for breast cancer: a retrospective study. J Altern Complement Med. 2013;19:905–910.
    10. Shin MS et al. The Effects of AHCC®, a Standardized Extract of Cultured Lentinura edodes Mycelia, on Natural Killer and T Cells in Health and Disease: Reviews on Human and Animal Studies. J Immunol Res. 2019 Dec 20;2019:3758576. doi: 10.1155/2019/3758576. PMID: 31930148; PMCID: PMC6942843.
    11. Dai X et al. Consuming Lentinula edodes (Shiitake) Mushrooms Daily Improves Human Immunity: A Randomized Dietary Intervention in Healthy Young Adults. J Am Coll Nutr. 2015;34(6):478-487. doi:10.1080/07315724.2014.950391
    12. Terakawa N et al. Immunological effect of active hexose correlated compound (AHCC) in healthy volunteers: a double-blind, placebo-controlled trial. Nutr Cancer. 2008;60(5):643-51. doi: 10.1080/01635580801993280. PMID: 18791928.
    13. Choi JY et al. Dietary supplementation with rice bran fermented with Lentinus edodes increases interferon-γ activity without causing adverse effects: a randomized, double-blind, placebo-controlled, parallel-group study. Nutr J. England; 2014;13:35
    14. Kabir Y et al. Effect of shiitake (Lentinus edodes) and maitake (Grifola frondosa) mushrooms on blood pressure and plasma lipids of spontaneously hypertensive rats. J Nutr Sci Vitaminol (Tokyo). 1987 Oct;33(5):341-6. doi: 10.3177/jnsv.33.341. PMID: 3443885.
    15. Spim SRV et al. Effects of Shiitake Culinary-Medicinal Mushroom, Lentinus edodes (Agaricomycetes), Bars on Lipid and Antioxidant Profiles in Individuals with Borderline High Cholesterol: A Double-Blind Randomized Clinical Trial. Int J Med Mushrooms. 2021;23(7):1-12. doi: 10.1615/IntJMedMushrooms.2021038773. PMID: 34375514.
    16. Handayani D et al. Dietary Shiitake Mushroom (Lentinus edodes) Prevents Fat Deposition and Lowers Triglyceride in Rats Fed a High-Fat Diet. J Obes. 2011;2011:258051. doi:10.1155/2011/258051
    17. Morales D et al. Modulation of human intestinal microbiota in a clinical trial by consumption of a β-D-glucan-enriched extract obtained from Lentinula edodes. Eur. J. Nutr. 2021; (60):3249–3265.
    18. Ciric L et al. In vitro assessment of shiitake mushroom (Lentinula edodes) extract for its antigingivitis activity. J Biomed Biotechnol. 2011;2011:507908. doi: 10.1155/2011/507908. Epub 2011 Sep 28. PMID: 21966183; PMCID: PMC3182071.
    19. Rincão VP et al. Polysaccharide and extracts from Lentinula edodes: structural features and antiviral activity. Virol J. 2012 Feb 15;9:37. doi: 10.1186/1743-422X-9-37. PMID: 22336004; PMCID: PMC3292946.
    20. Roszczyk A et al. Immunomodulatory Properties of Polysaccharides from Lentinula edodes. International Journal of Molecular Sciences. 2022; 23(16):8980. doi.org/10.3390/ijms23168980
    21. Sheldrake M. Entangled Life: How fungi make our worlds, change our minds and shape our futures. London: The Bodly head; 2020.
    22. Toh DS et al. Effect of mushroom diet on pharmacokinetics of gabapentin in healthy Chinese subjects. Br J Clin Pharmacol. 2014;78(1):129-134.24168107
    23. Okuda Y. Sustainability perspectives for future continuity of mushroom production: The bright and dark sides. Front. Sustain. Food Syst. 2022;6:1026508. doi:10.3389/fsufs.2022.1026508
    24. Sayner, A. How To Grow Shiitake Mushrooms: The Ultimate Guide. https://grocycle.com/how-to-grow-shiitake-mushrooms/. Accessed 10th October 2023.
An ‘aromatic’ remedy, high in volatile essential oils, was most often associated with calming and sometimes ‘warming’ the digestion. Most kitchen spices and herbs have this quality: they were used both as flavouring and to ease the digestion of sometimes challenging pre-industrial foods. Many aromatics are classed as ‘carminatives’ and are used to reduce colic, bloating and agitated digestion. They also often feature in respiratory remedies for colds, chest and other airway infections. They are also classic calming inhalants and massage oils, and are the basis of aromatherapy for their mental benefits.
Astringent taste
The puckering taste you get with many plants (the most familiar is black tea after being stewed too long, or some red wines) is produced by complex polyphenols such as tannins. Tannins are used in concentrated form (eg from oak bark) to make leather from animal skins. The process of ‘tanning’ involves the coagulation of relatively fluid proteins in living tissues into tight clotted fibres (similar to the process of boiling an egg). Tannins in effect turn exposed surfaces on the body into leather. In the case of the lining of mouth and upper digestive tract this is only temporary as new mucosa are replenished, but in the meantime can calm inflamed or irritated surfaces. In the case of open wounds tannins can be a life-saver – when strong (as in the bark of broadleaved trees) they can seal a damaged surface. One group of tannins, the reddish-brown ‘condensed tannins’ are procyanidins, which can reduce inflammation and oxidative damage.
Bitters are a very complex group of phytochemicals that stimulate the bitter receptors in the mouth. They were some of the most valuable remedies in ancient medicine. They were experienced as stimulating appetite and switching on a wide range of key digestive functions, including increasing bile clearance from the liver (as bile is a key factor in bowel health this can be translated into improving bowel functions and the microbiome). Many of these reputations are being supported by new research on the role of bitter receptors in the mouth and elsewhere round the body. Bitters were also seen as ‘cooling’ reducing the intensity of some fevers and inflammatory diseases.
Blue-purple colouring
Any fruits with a blue-purple colouring contain high levels of the polyphenols known as anthocyanins. These work 1) on the walls of small blood vessels, helping to maintain capillary structure to reduce a key stage in inflammation, and improving the microcirculation to the tissues; 2) to improve retinal function and vision; 3) to support connective tissue repair around the body.
Traditional ‘cold’ or cooling’ remedies often contain bitter phytonutrients such a iridoids (gentian), sesiquterpenes (chamomile), anthraquinones (rhubarb root), mucilages (marshmallow), some alkaloids and flavonoids. They tend to influence the digestive system, liver and kidneys. Cooling herbs do just that; they diffuse, drain and clear heat from areas of inflammation, redness and irritation. Sweet, bitter and astringent herbs tend to be cooling.
Traditional ‘hot’ or ‘heating’ remedies, often containing spice ingredients like capsaicin, the gingerols (ginger), piperine (black or long pepper), curcumin (turmeric) or the sulfurous isothiocyanates from mustard, horseradich or wasabi, generate warmth when taken. In modern times this might translate as thermogenic and circulatory stimulant effects. There is evidence of improved tissue blood flow with such remedies: this would lead to a reduction in build-up of metabolites and tissue damage. Heating remedies were used to counter the impact of cold, reducing any symptoms made worse in the cold. .
Mucilages are complex carbohydrate based plant constituents with a slimy or ‘unctuous’ feel especially when chewed or macerated in water. Their effect is due simply to their physical coating exposed surfaces. From prehistory they were most often used as wound remedies for their soothing and healing effects on damaged tissues. Nowadays they are used more for these effects on the digestive lining, from the throat to the stomach, where they can relieve irritation and inflammation such as pharyngitis and gastritis. Some of the prominent mucilaginous remedies like slippery elm, aloe vera and the seaweeds can be used as physical buffers to reduce the harm and pain caused by reflux of excess stomach acid. Mucilages are also widely used to reduce dry coughing. Here the effect seems to be by reflex through embryonic nerve connections: reduced signals from the upper digestive wall appear to translate as reduced activity of airway muscles and increased activity of airway mucus cells. Some seed mucilages, such as in psyllium seed, flaxseed (linseed) or guar bean survive digestion to provide bulking laxative effects in the bowel. These can also reduce rate of absorption of sugar and cholesterol. .
New-mown hay aroma
The familiar country odour of haymaking, of drying grass and other plants, is largely produced by coumarins (originally isolated from tonka beans – in French coumarou) and widely used in perfumery. They are chemically categorised as benzopyrone lactones and are important phytochemicals, with strong antioxidant activity in the laboratory and likely effects in modulating inflammation. They were most often associated with the calming effect linked to their use in stuffing mattresses and pillows and plants, high In coumarins were commonly used for these properties.
Resins are most familiar as tacky discharges from pine trees (and as the substance in amber, and rosin for violin bows). They were most valued however as the basis of ancient commodities like frankincense and myrrh (two of the three gifts of the Three Wise Men to the baby Jesus) and getting access to their source was one benefit to Solomon for marrying the Queen of Sheba (now Ethiopia). Resins were the original antiseptic remedies, ground and applied as powders or pastes to wounds or inflamed tissues, and were also used for mummification. With alcohol distillation it was found that they could be dissolved in 90% alcohol and in this form they remain a most powerful mouthwash and gargle, for infected sore throats and gum disease. They never attracted much early research interest because they permanently coat expensive glassware! For use in the mouth, gums and throat hey are best combined with concentrated licorice extracts to keep the resins in suspension and add extra soothing properties. It appears that they work both as local antiseptics and by stimulating white blood cell activity under the mucosal surface. They feel extremely effective!
The salty flavour is immediately distinctive. A grain dropped onto the tongue is instantly moistening and a sprinkle on food enkindles digestion. This easily recognisable flavour has its receptors right at the front of the tongue. The salty flavor creates moisture and heat, a sinking and heavy effect which is very grounding for the nervous system and encourages stability. People who are solid and reliable become known as ‘the salt of the earth'.
The sharp taste of some fruits, and almost all unripe fruits, as well as vinegar and fermented foods, is produced by weak acids (the taste is generated by H+ ions from acids stimulating the sour taste buds). Sour taste buds are hard-wired to generate immediate reflex responses elsewhere in the body. Anyone who likes the refreshing taste of lemon or other citrus in the morning will know that one reflex effect is increased saliva production. Other effects are subjective rather than confirmed by research but there is a consistent view that they include increased digestive activity and contraction of the gallbladder.
In the days when most people never tasted sugar, ‘sweetness’ was associated with the taste of basic foods: that of cooked vegetables, cereals and meat. In other words sweet was the quality of nourishment, and ‘tonic’ remedies. Describing a remedy as sweet generally led to that remedy being used in convalescence or recovery from illness. Interestingly, the plant constituents most often found in classic tonics like licorice, ginseng are plant steroids including saponins, which also have a sweet taste.

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