A voice for
herbal medicine

We share traditional, scientific and practical insights written by experienced herbalists and health experts from the world of herbal medicine and natural health

Black walnut is an anthelmintic, antiparasitic and dermatological

Black walnut

Juglans nigra

Juglandaceae

Black walnut has a gradual stimulant and cleansing action in the digestive system, relieving constipation and diarrhoea. Its antifungal and antiparasitic actions make it effective for both internal and external use.

Last reviewed March 9, 2025

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.

Sustainability Status
Key benefits
  • Cholagogue
  • Anthelmintic
  • Antifungal
  • Pancreatic stimulant
  • Depurative
  • Tonic
  • Dermatological agent

  • How does it feel?

    The perfectly round green fruits are rough and hairy in texture, and, when newly harvested they have a strong citrus fragrance. Once they have fallen from three, they subsequently  turn black. Black walnut has a mild initial taste, not as bitter as might be expected. There is a stronger, aromatic, slightly resinous, even spicy, aftertaste. The edible nut is unlike other walnuts, with a rich, slightly oily taste, again with a pungent and fragrant element. It is often considered a delicacy (1,2).

    Black walnut (Juglans nigra)
    Black walnut (Juglans nigra)
    Black walnut (Juglans nigra)

  • What can I use it for?

    Black walnut (Juglans nigra)
    Black walnut (Juglans nigra)

    Black walnut hull and leaf have been used together to elicit a stimulating and cleansing action in the digestive system, encouraging the flow of bile and relieving stagnant conditions. Acting gradually to ease congestion, the mucous membranes are toned by the action of this aromatic bitter. It has been used to relieve both constipation and diarrhoea (3,4). The internal blood cleansing action is indicated in treating skin conditions such as acne and impetigo. This action is especially appreciated in aiding chronic conditions as part of a whole picture of improving digestion and elimination in a gradual and effective process (5).

    The strong astringency of the tannins in the hull and leaf of black walnut, (possibly combined with the juglone constituent) is responsible for the anthelmintic action of the herb in the gut (6). Black walnut encompasses the whole range of antiparasitic, antifungal, antimicrobial and anthelmintic actions. This, partnered with the cleansing, mild cathartic effect, makes it an appropriate choice for treating a range of eruptive skin conditions, as well as candida and athlete’s foot (7).

    Tannins play a key role in the anticatarrhal properties, as explored by physio-medicalists who explored their use in treating chronic mucous membrane inflammation, such as in cases of tonsillitis (3). Astringent tannins are also helpful in leaf compresses applied for wounds, burns and skin conditions. Compresses additionally cool and relieve inflammation associated with boils, impetigo, and acne. A short decoction of the outer hull can be added to hair rinses to encourage hair growth and strengthen the hair. This is especially useful for treating alopecia (3). The edible nuts are currently being researched in a supportive role as a health supplement due to their rich phenolic compound content (8).

  • Into the heart of black walnut

    Black walnut produces juglone through releasing chemicals into the soil inhibiting the germination of competing plants (9). This defensive nature is also expressed through the fragrance of the tannin-rich leaves giving protection from many insect pests, and finally in the extraordinary hardness of the case surrounding the nut (2). When used in medicine, the aromatic bitter in black walnut can provide this protection to the patient, cleansing them of toxins, parasites and intestinal worms.

    The fresh hull contains many esters responsible for the sweet citrus fragrance. These give black walnut a very different aromatic composition from the English walnut (Juglans regia) (8). Once dried and powdered, the blackened hull still holds fragrance but now a distinctly drying, cooling nature is evident upon breathing it in. Cooling for inflammatory conditions, black walnut also supports the body’s tissues with a tonic and relaxant effect (3).

    The edible nut is extracted with difficulty, but it is worth the effort as it is highly nutritious (8). The nut has an intense richness with an aromatic, slightly resinous aftertaste.

  • Traditional uses

    Black walnut (Juglans nigra)
    Black walnut (Juglans nigra)

    In the eastern states where black walnut was widely distributed, several Native American nations used black walnut medicinally. The Meskwaki charred old bark from the black walnut and applied it in a wash to treat snake bite (10). The Delaware drank a strong tea made from the bark of young twigs over two days to remove bile from the intestines and applied the juice of the green hull topically to cure ringworm. They used the leaves as strewing herbs against insect infestation in the home (4).

    In 1830, Rafinesque described the decoctions of the green rind being rubbed on tetters and ringworm. The rind was also classified as a vermifuge and diaphoretic, even antisyphilitic. Thirty years later, Gunn records a strong syrup of the leaves taken for scrofula with a handful steeped in a pint of boiling water, strained and sweetened. A third of this amount taken daily was not expected to give fast results, but acted over time on the lymphatic system to produce firmer muscles and healthier skin. A strong tincture of green walnuts was recommended for bilious colic (10).

    These treatments passed into modern use by physiomedicalists and other herbalists. Black walnut is currently associated with treating skin conditions such as psoriasis, eczema and ringworm. Black walnut infusion was also used as a gargle for diphtheria (11).

  • Traditional actions

    Herbal actions describe therapeutic changes that occur in the body in response to taking a herb. These actions are used to express how a herb physiologically influences cells, tissues, organs or systems. Clinical observations are traditionally what have defined these actions: an increase in urine output, diuretic; improved wound healing, vulnerary; or a reduction in fever, antipyretic. These descriptors too have become a means to group herbs by their effects on the body — herbs with a nervine action have become the nervines, herbs with a bitter action are the bitters. Recognising herbs as members of these groups provides a preliminary familiarity with their mechanisms from which to then develop an understanding of their affinities and nuance and discern their clinical significance.

    Western 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

    Black walnut (Juglans nigra)
    Black walnut (Juglans nigra)

    Digestive system

    As a bitter, black walnut stimulates appetite and encourages bile flow. With a relaxant, decongesting action, a tincture of the leaves and nuts is recommended for bilious colic (1). The antibacterial, antifungal and anthelmintic properties provide primary uses against Helicobacter pylori, Candida albicans and intestinal worms (3).

    Cardiovascular

    Black walnut is regarded by physiomedicalists as a vasocompressor through the astringent properties and as a vasotonic (3).

    Endocrine

    A traditional remedy for goitre, black walnut tincture has been used in drop doses for treating hypothyroidism (12). It may defer diabetic complications and is seen as a possible pancreatic stimulant with an additional hypoglycaemic action (13,3).

    Whether used internally or as an external application, black walnut has been recommended particularly for eruptive and infected skin conditions. Acting both as a blood cleansing depurative and alterative it has been valued for a wide range of antibacterial, antifungal and antiparasitic actions when applied topically. A bath is recommended for itchy skin conditions (14).

    Hair

    Black walnut eases inflammation on the scalp and stimulates hair growth, indicating it in treatments for alopecia (15).

  • Research

    Black walnut (Juglans nigra)
    Black walnut (Juglans nigra)

    There is a lack of significant clinical studies on the use of black walnut hull.  Black walnut hulls were not included in the Commission E statement and the majority of medicinal recommendations are based on traditional use.

    Antitumor activity of Juglans nigra (black walnut) extractives

    This study used extract of black walnut to treat spontaneous and/or transplanted tumors in mice and examined the potential anticancer activities of the following compounds: Ellagic acid, juglone, and isolated fractions (strong acids, weak acids, and alkaloids). These were injected intraperitoneally for 9–12 days. The results showed that ellagic acid, juglone, and the strong acids fraction depressed the tumor growth rate significantly (16).

    A further study examined juglone and plumbagin 5-O derivatives and their effect on inhibiting the growth of cancer cells in vitro. It explored the inhibitory activity against six apoptosis-resistant cancer strains using synthesised analogues of juglone and plumbagin. This demonstrated that both constituents were cytostatic and able to overcome intrinsic resistance of U373 cancer cells to pro-apoptotic stimuli (17).

    Juglone from walnut produces cardioprotective effects against isoproterenol-induced myocardial injury in SD rats.

    Cardioprotective effects of juglone and the possible mechanism of action have also been researched. In this study using Sprague-Dawley (SD) rats, pretreatment with juglone (1.3 mg/kg, i.p. ) and atenolol (1 mg/kg i.p.) were given in separate experiments for five days and followed by isoproterenol to induce a myocardial infarction. The effect was judged on results from electrocardiograph readings, cardiac biomarkers (cTnl, CPK, CK-MB, LDH, ALT and AST) and histopathological study.  Juglone was confirmed as a potential cardioprotective agent (18).

    An overview of phytochemicals and potential health-promoting properties of black walnut

    The potential properties for dietary consumption of the nuts in supporting health is the most current area of research. Further clinical studies are still required,  and there are limited in vitro and in vivo studies. However, this study confirms that black walnut is rich in phenolics and contains higher levels of phytosterols, unsaturated fatty acids and tocopherols than many other nuts. Several studies were found to support antibacterial and antioxidant activities and the data led to a presumption that regular black walnut consumption might contribute to protection against many lifestyle and age-related diseases. Future research and clinical studies were recommended (8).

    Black walnut (Juglans nigra) extracts inhibit proinflammatory cytokine production from lipopolysaccharide-stimulated human promonocytic cell line U-937

    Further to the more general overview, a study was carried out using extracts of 10 black walnut cultivars. Five cultivars were examined and their effects on the expression of six human inflammatory cytokines/chemokines were evaluated using methanolic extracts. Results from cytotoxicity and viability assays revealed no toxic effect. The findings suggest that not all, but extracts from certain cultivars are promising biological candidates for potentially decreasing the severity of inflammatory disease (19).

  • Did you know?

    Over 700 cultivars of black walnut have been identified. Quality black walnut hardwood is highly valued as timber and used for veneer. The shells are ground to be included in insecticides and have been used for blast cleaning and polishing on an industrial scale. The hulls provide an excellent, fast brown dye which does not require a mordant (2).

Additional information

  • Botanical description

    The tree can grow up to fifty metres high with a straight trunk bearing deeply fissured bark. The leaflets are compound, with between eleven and twenty-three to the leaf stalk. Although the leaves of both walnuts are compound, those of the black walnut are more lanceolate than those of the common walnut and have toothed edges. The underside is hairy and crushing them produces a strong aroma which discourages insects.

    The tree bears greenish female flowers in spikes on the current year’s growth and yellow male catkins on axillary buds on the previous year’s growth (24). These appear in spring along with the clusters of newly opening leaves. They are followed by round fruits with a green, rough textured, thick outer hull which mature from September on into autumn.

    They are especially round to enable them to roll away from the parent tree, which excretes toxic naphthalene glucoside into the soil where it is converted into juglone to inhibit germination of competing plants. When fresh, the green hull emits a delightful citrus perfume. An extraordinarily hard inner shell contains the tasty nut which is safe for consumption (2).

  • Common names

    • American walnut
    • Eastern black walnut
    • Round nut tree

  • Safety

    All parts of the tree except the nut kernels contain juglone which is potentially toxic. Black walnut should not be taken internally in high doses or long-term. Juglone is mutagenic (15). No increase has been found in harmful effects on the foetus in limited use in pregnant women. There is no data available for lactation; so, it is best avoided. It should be noted that the juglone content in hulls varies with different cultivars and different months of growth. Black walnut hulls do not have ‘generally recognised as safe’ (GRAS) status (11). Not to be taken in conjunction with antacid suspensions (13).

  • Interactions

    None known (11,21,22)

  • Contraindications

    Avoid prescribing if the patient has tinnitus.  Do not prescribe on its own for more than three days (7). Not to be taken in conjunction with proprietary antacid suspensions, especially those containing bismuth. Prolonged internal use is not advisable (13). None on current evidence (11,23).

  • Preparations

    • Tincture
    • Infusion/decoction
    • Powder
    • Capsules
    • Bath
    • Compress

  • Dosage

    • Tincture (ratio 1:2 | 25%): 1.5–5.5 ml per day
    • Fluid extract (1:1 | 25%): 10–20 drops per day (15)
    • Infusion/decoction: 2–4 ounces of the leaf, bark or rind twice to three times daily. One teaspoonful of inner bark or leaves and finely cut rind to one cup of boiling water. Drink 1–4 cups daily, a large mouthful at a time (1).
    • Other preparations: For a bath, use two pints of leaf infusion added to bathwater (14).

  • Plant parts used

    • Hull
    • Leaf

  • Constituents

    • Naphthoquinones: Juglone and plumbagin (11)
    • Phenolic acids: Tannins, ellagic acid
    • Volatile oil
    • Flavonoids: Hyperoside and quercetin ‘(3)’
    • Minerals: Iodine, iron, potassium, sulphur, zinc ‘(7)’
Black walnut (Juglans nigra)

  • Habitat

    In Britain the black walnut has been planted as an ornamental tree in parks since 1656  or possibly earlier (25). It is usually seen standing alone, away from other trees. Black walnut is native to the central and eastern states of America where it prefers growing in rich, moist but well-drained soil, often over a limestone base. This fact encouraged settlers to regard those sites favoured by the tree as ideal places to live and farm. It was introduced to much of Europe, including Russia, China, and New Zealand between the early seventeenth and twentieth centuries (26).

  • Sustainability

    Sustainability status greenThe sustainability of black walnut is regarded as of Least Concern with a G5 rating and stable (26.27,28). The trees are grown in numerous countries in Europe as well as in America, predominantly as a valued hardwood. However, in America many black walnut farms supply the nuts for food. More than 700 hybrids have been released in the past hundred years aiming to breed trees with greater yield and thinner shells. The modern practice of alley cropping has made increased cultivation of young trees for the nuts even more viable (26).

    Habitat loss and over-harvesting from the wild are two of the biggest threats faced by medicinal plant species. There are an increasing number of well-known herbal medicines at risk of extinction. We must, therefore, ensure that we source our medicines with sustainability in mind.

    The herb supplement industry is growing at a rapid rate and until recent years a vast majority of medicinal plant produce in global trade was of unknown origin. There are some very real and urgent issues surrounding sustainability in the herb industry. These include environmental factors that affect the medicinal viability of herbs, the safety of the habitats that they are taken from, as well as the welfare of workers in the trade.

    The botanical supply chain efforts for improved visibility (transparency and traceability) into verifiably sustainable production sites around the world is now certificated through the emergence of credible international voluntary sustainability standards (VSS). 

    Read our article on Herbal quality and safety: What to know before you buy and Sustainable sourcing of herbs to learn more about what to look for and questions to ask suppliers about sustainability.

  • Quality control

    Herbal medicines are often very safe to take; however, their safety and efficacy can be jeopardised by quality issues. So, it is important to buy herbal medicines from a reputable supplier, from sources known to test their herbs to ensure there is no contamination, adulteration or substitution with incorrect plant matter, as well as ensuring that recognised marker compounds are at appropriate levels in the herbs.

    Some important quality assurances to look for are certified organic labelling, the correct scientific/botanical name, and the availability of information from the supplier about ingredient origins. A supplier should be able to tell you where the herbs have come from, what contaminants are not in the herb, and what the primary compounds are.

  • How to grow

    Seed should be sown in March to germinate in the same or following year. In addition to lateral roots, black walnut also has a deep taproot. This needs a deep hole when planting a sapling, with rich soil of either a sandy or silty clay loam offering control for a steady water supply in drought or flooding conditions. Sun and light are required for strong growth which is fast in younger trees. Heavy shade is detrimental. Careful weeding is required around the tree, along with protection from deer, rabbits and squirrels. The trees stand winter frosts well, but prefer a moist, warm climate from spring to autumn. Tender growth is not frost-hardy. A sheltered site with light shade is recommended.  Black walnut is more resistant to honey fungus than the common walnut.

    Grafting and budding are other successful ways of propagation. A young tree may reach a height of 12–15 metres by age 20. Any necessary pruning of the young tree should be done in spring just before the leaves appear. Black walnut can bear fruit after eight years, however, it is not expected to produce a heavy crop until around 30 years old (26,29,30).

  • Recipe

    Black walnut foot powder

    This easy to make foot powder* provides astringent and antifungal relief for the common condition of athlete’s foot. The powder can be kept in a jar marked for external use only.

    Ingredients

    • 1/2 cup powdered white clay
    • One tablespoon powdered black walnut hull
    • 1/2 tablespoon powdered sage
    • 1/2 tablespoon powdered myrrh
    •  One teaspoon of tea tree essential oil

    Method

    • Combine the powders
    • Add the essential oil carefully
    • Allow to dry
    • Keep in a bottle or screw top jar
    • Apply once or twice daily

    *Adapted from Rosemary Gladstar, Herbal recipes for vibrant health (20)

     

  • References

    1. Hutchens A. Indian Herbalogy of North America. Shambhala; 1973.
    2. Stapley C. The Tree Dispensary. Aeon Books; 2021.
    3. Menzies-Trull C. Herbal Medicine Keys to Physiomedicalism Including Pharmacopoeia. Faculty Of Physiomedical Herbal Medicine (Fphm; 2013.
    4. Tantaquidgeon G. Folk Medicine of the Delaware and Related Algonkian Indians. Harrisburg: Pennsylvania Historical and Museum Commission; 1972.
    5. Kat Maier. Energetic Herbalism: A Guide to Sacred Plant Traditions Integrating Elements of Vitalism, Ayurveda, and Chinese Medicine. Chelsea Green Publishing; 2021.
    6. Mowrey DB. The Scientific Validation of Herbal Medicine: How to Remedy and Prevent Disease with Herbs, Vitamins, Minerals, and Other Nutrients. Keats Pub; 1999.
    7. Holmes P. The Energetics of Western Herbs. Snow lotus press; 2020.
    8. Vu DC, Nguyen THD, Ho TL. An overview of phytochemicals and potential health-promoting properties of black walnut. RSC Advances. 2020;10(55):33378-33388. https://doi.org/10.1039/d0ra05714b
    9. Sumner J, Plotkin MJ, Timber Press. The Natural History of Medicinal Plants. Timber Press, Druk; 2017.
    10. Erichsen-Brown C. Medicinal and Other Uses of North American Plants : A Historical Survey with Special Reference to the Eastern Indian Tribes. Dover Publications; 1989.
    11. Mills S, Bone K. The Essential Guide to Herbal Safety. Elsevier Churchill Livingstone; 2005.
    12. Wood M. The Practice of Traditional Western Herbalism. North Atlantic Books; 2013.
    13. Barker J. The Medicinal Flora of Britain & Northwest Europe : A Field Guide, Including Plants Commonly Cultivated in the Region. Winter Press; 2001.
    14. Green J. The Herbal Medicine-Makers’ Handbook : A Home Manual. Crossing Press; 2000.
    15. Duke JA. Duke’s Handbook of Medicinal Herbs of the Bible. Crc Press; 2007.
    16. Bhargava UC, Westfall BA. Antitumor Activity of Juglans nigra (Black Walnut) Extractives. Journal of Pharmaceutical Sciences. 1968;57(10):1674-1677. https://doi.org/10.1002/jps.2600571009
    17. Fiorito S, Genovese S, Taddeo VA, Mathieu V, Kiss R, Epifano F. Novel juglone and plumbagin 5- O derivatives and their in vitro growth inhibitory activity against apoptosis-resistant cancer cells. Bioorganic & Medicinal Chemistry Letters. 2016;26(2):334-337. https://doi.org/10.1016/j.bmcl.2015.12.017
    18. Ahmad T, Khan T, Tabassum T, et al. Juglone from Walnut Produces Cardioprotective Effects against Isoproterenol-Induced Myocardial Injury in SD Rats. Current issues in molecular biology. 2022;44(7):3180-3193. https://doi.org/10.3390/cimb44070220
    19. Ho KV, Schreiber KL, Vu DC, et al. Black Walnut (Juglans nigra) Extracts Inhibit Proinflammatory Cytokine Production From Lipopolysaccharide-Stimulated Human Promonocytic Cell Line U-937. Frontiers in Pharmacology. 2019;10. https://doi.org/10.3389/fphar.2019.01059
    20. Gladstar R. Rosemary Gladstar’s Herbal Recipes for Vibrant Health : 175 Teas, Tonics, Oils, Salves, Tinctures, and Other Natural Remedies for the Entire Family. Storey Pub.; 2015.
    21. Stargrove MB, Treasure J, Mckee DL. Herb, Nutrient, and Drug Interactions : Clinical Implications and Therapeutic Strategies. Mosby Elsevier; 2008.
    22. Natural Medicines. Black walnut. naturalmedicines.therapeuticresearch.com. Published 2024. https://naturalmedicines.therapeuticresearch.com/databases/food
    23. Scripta Rustica. Advanced Herbal Pharmacy: The Practioner’s Guide to Preparation, Formulation, & Compounding. Lincoln Town Press; 2020.
    24. Mitchler C, Woeste K, Pijut P. Black Walnut. Genome Mapping and Molecular Breeding in Plants. 2007;7.
    25. Campbell-Culver M. The Origin of Plants. Random House; 2014.
    26. Nicolescu VN, Rédei K, Vor T, et al. A review of black walnut (Juglans nigra L.) ecology and management in Europe. Trees. 2020;34(5):1087-1112. https://doi.org/10.1007/s00468-020-01988-7
    27. Nature Serve Explorer. Black walnut. explorer.natureserve.org. Published 2024. https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.141124/Juglans_nigra
    28. Stritch L. IUCN Red List of Threatened Species: Juglans nigra. IUCN Red List of Threatened Species. Published February 16, 2018. Accessed February 21, 2025. https://www.iucnredlist.org/species/62019712/62019714
    29. Forest Research. Black walnut (BWA) – Forest Research. Forest Research. Published April 18, 2024. Accessed February 21, 2025. https://www.forestresearch.gov.uk/tools-and-resources/tree-species-database/black-walnut-bwa/
    30. Trust W. Black Walnut (Juglans nigra) – British Trees. Woodland Trust. https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/british-trees/a-z-of-british-trees/black-walnut/

Related herbs

Sage (Salvia officinalis)

Sage

Neem (Azadirachta indica)

Neem

Related conditions

Acne

Acne

Candida

Candida

Related articles

Cleansing from the Ayurvedic perspective: Which cleanse is suitable?

Cleansing from the Ayurvedic perspective: Which cleanse is suitable?

Bitters: Why herbalists love them and how they help digestion

Bitters: Why herbalists love them and how they help digestion

Aromatic
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
The astringent 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.
Bitter
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.
Cooling
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.
Hot
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..
Mucilaginous
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..
Pungent
The pungent flavour refers to the powerful taste of hot spices including mustard (Brassica spp.), ginger (Zingiber officinale), horseradish (Amoracia rusticana), chilli (Capsicum spp.), and garlic (Allium sativum). These herbs act to enliven and invigorate the senses, and they often also have heating qualities. Unlike other tastes, the effect is not linked to a specific receptor on the tongue and instead acts through direct irritation of tissues and nerve endings. Energetically, pungent herbs are known to disperse energy (qi) throughout the body. Pharmacologically, pungent herbs dry excess moisture and mucus, as well as stimulate digestion and metabolism.
Resinous
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!
Salty
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'.
Sharpness
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.
Sour
The sour taste occurs because of the stimulation of hydrogen ions which trigger the sour taste receptors on the tongue. The more acidic a substance, the more hydrogen ions will be released. The sour taste comes from acidic substances including citrus, fermented foods, tannins, and vinegars. Sour foods and herbs absorb excess moisture, whilst also increasing the production of saliva. Energetically, sour substances tonify the lungs, playing a role in disease prevention. Excessive use, however, can result in malabsorption of nutrients. Examples of sour herbs include, rosehips (Rosa canina), raspberry (Rubus idaeus), rhubarb (Rheum palmatum), schisandra (Schisandra chinensis), hawthorn (Crataegus monogyna) and ginkgo (Ginkgo biloba).
Sweet
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.
Umami
The umami taste was originally discovered in 1985 in Japan and is directly translated from the Japanese as a ‘pleasant savoury taste’. It is referred to as the ‘fifth taste’ and is a salty, rich, and meaty flavour. The umami flavour is produced by amino acids (glutamic acid and aspartic acid) found in many food and plant sources including tomatoes, mushrooms, seaweeds and soy-based foods. Umami foods can improve nutritional absorption and digestion as there are also umami receptors in the gut as well as the mouth. Examples of umami herbs include green tea (Camellia sinensis), reishi (Ganoderma lucidum), nettle (Urtica dioica), cordyceps (Ophiocordyceps sinensis), shitake (Lentinula edodes) and bladderwrack (Fucus vesiculosus).

Sign up to our Newsletter

Sign up to our newsletter to receive the very latest in herbal insights.