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Mint leaf, usually as tea, and the volatile oil are still both widely used for digestive upsets

Mint

Mentha x piperita, Mentha arvensis, and other species Lamiaceae

Among the world’s oldest medicinal herbs, mints have been used medicinally and for culinary purposes for many centuries in both eastern and western traditions. The characteristic minty aroma and taste is largely due to their ingredient menthol.

  • How does it feel?

    As you press mint leaves from the garden the first impact is the minty aroma from its menthol. This is a key ingredient of the essential oil of the mint family (it is actually a crystalline solid oil at room temperature, though liquefies at body temperature, i.e. when we taste it). Menthol activates the same nerve receptors that cold does, so even when inhaled there is a sensation of cooling. Certainly the smell of mints is most often described in this way.

    When you make a strong peppermint tea, again there is an immediate cooling effect of the menthol in the mouth. Then other sensations come through: there are more aromatic, almost pungent flavours as the other volatile oils work through to the palate. In the finish you will probably pick up the dryness of the astringent tannins, actually a large fraction of mint constituents.

  • What can I use it for?

    Mints provide ideal herbal teas to try, for a wide range of digestive disorders including heartburn, dyspepsia, cramping, distension, colic and flatulence, nausea and vomiting. If mint is helpful there will be almost immediate relief and you can be encouraged to increase the strength: perhaps to two or more teabags per cup, steeped for at least 15 minutes (although note the different dosage effects in the next section). If it is not helpful there will be no harm done and you could try a different tea like chamomile, fennel, lemon balm or ginger for example, until you find the one that suits you best.

    The benefits of peppermint oil in the treatment of irritable bowel syndrome are well-supported by clinical trials.  It may also have stronger effects in relieving dyspepsia, nausea (so worth trying if mint teas are partially helpful), as well as gallbladder and bile ducts pain. In this case either use proprietary or prescription peppermint oil capsules, or add the oil to peppermint tea in stepped up levels from 3 to 8 drops. Peppermint oil must never be swallowed neat and should be used cautiously if you have inflammatory diseases of the digestive system or have gallstones.

    Due to their menthol component, you will get some benefits for symptoms of coughs and colds from mint teas, particularly if you inhale the steam coming off the hot tea. A stronger effect however will be from inhaling peppermint oil, particularly with steam.

    Mints are uplifting to the mood, yet likely to improve sleep if taken last thing before bed. There is evidence that mint teas can reduce palpitations or other cardiac consequences of anxiety.

    Peppermint oil applied to the skin may relieve neuralgia, pruritus and headaches and can be considered to heal cracked nipples when breastfeeding.

  • Into the heart of Mint

    The mint family all have a high levels of essential oil containing menthol, which with another constituent menthone, gives the plant its distinctive scent and taste.

    It is also the component responsible for mints’ medicinal activity. Menthol acts as an analgesic, working by cooling muscle, circulatory and other pains, also separately relieving the strain and tension that may contribute to pain and headaches.

    In the digestive tract, menthol will reduce the contractile responses of the digestive muscles, certainly by stimulating cold receptors in the stomach and possibly by inhibition of calcium influx into the smooth muscle of the gut wall, so relieving heartburn, digestive cramping and colic and even by reflex calming excessive heart activity in anxiety, like palpitations. Menthol may even directly activate calming GABA receptors in the nervous system.

    Confusingly the subjective effect of taking mint has sometimes been described ‘warming’ (‘pungent’ in some traditional descriptions). When taken, especially in high doses, during colds and fever it has diaphoretic properties, ie it encourages perspiration and feels warming to the person concerned. Nevertheless by increasing sweat production mints actually reduce fever and so the net effect remains cooling.

    Menthol is a volatile aromatic and when inhaled can decongest and remove excessive levels of phlegm from the airways.

    The dose and method of taking the remedy are important. A low dose is relaxing, a medium dose benefits inflammatory conditions and high dosages clear excess congestion.

  • Traditional uses

    Mints have been traditionally used in the relief of digestive disorders, and to balance the effects of stronger remedies, especially stimulating laxatives. Their beneficial actions on the digestive system extend to the use of the tea for nausea, as well as morning and travel sickness. Members of the mint family are also widely used as diaphoretics (to stimulate perspiration in fevers and so help keep high temperatures in check – one reason why they are universally seen as ‘cooling’).

    With a key constituent menthol, mints not surprisingly have also been widely used for respiratory symptoms, to clear nasal passages, to relieve coughing in bronchial conditions and pneumonia, and for the temporary relief of sore throats. They have also seen to promote digestive, kidney and liver detox functions. Women have used mint teas to relieve painful periods.  Externally, peppermint oil has been used to relieve pain and itching, and as a mouthwash.  Bruised fresh mint and peppermint oil have a use in relieving headaches.  They have a reputation as mildly sedative, and were used in combination with other herbs to relieve nervous upsets.  They also have a long history as flavouring agents for teas, medicines, food and drink.

  • What practitioners say

    The most useful role of peppermint is as a tea in the treatment of various digestive upsets. Individuals with dyspeptic, flatulent or colicky symptoms divide approximately evenly between those who are relieved by peppermint and those who are not. It is a simple first step for anyone to find out in which category they fall: if there is any relief at all from taking a cup of simple tea then it is worth making it stronger, by steeping the teabag for 15 minutes and possibly using two per cup. If there is no relief it probably is worth trying a ‘warming’ remedy like fennel or ginger instead. If peppermint is helpful then chamomile may also work and more substantial benefits made be had with the stronger ‘cooling’ digestive remedies, the bitters (eg dandelion, artichoke, gentian root or wormwood). Practitioners may use the oil, particularly in enteric-coated capsules, for bowel irritability and as an ingredient of liniments or other topical applications. However there are gentler and as effective oils for inhalation purposes (such as oils of pine and aniseed).

    Digestion: Indicated in heartburn, nervous digestion, flatulence, bloating, IBS, ulcers, nausea and anorexia. The tea (though probably not the oil) can relieve gastritis and enteritis. The aromatic essential oils can help to alleviate morning sickness, vomiting and spasms in the gastrointestinal tract. The oil may relive gallbladder pain, though should be used with caution with gallstones themselves.

    Infections: Commonly used as a hot tea to influence diaphoresis (sweating) in colds and flu. Especially when also inhaled it can help unblock airways congestion and is indicated where the lungs are congested with catarrh and constricted by spasms, wheezing or asthma.

    Mental health: Mint teas may relieve mental and emotional tension and especially cardiac effects of anxiety.

    Women’s health: Indicated in menstrual congestion, pain and amenorrhoea due to its ability to reduce congestion in the body. There is some evidence to point to the use of the tea in PCOS and other hormonal problems.

    Topical: Peppermint oil when applied to the skin can cool and soothe skin inflammation, hot flushes and allergic itching. It is a prime remedy to relive headaches and ‘hot’ neuralgic pain. It should be considered for cracked nipples in breastfeeding mothers.

  • Research

    The vast majority of modern research literature for mints relates to peppermint oil. As a strong extract of the menthol-containing mint family this supports all their traditional reputations to some extent.  Peppermint oil exerts a significant antispasmodic, carminative effect on the gastrointestinal tract, with a range of evidence pointing to the relief of dyspepsia, stomach spasm and nausea. There seems also to be an improvement in stomach performance generally. There is evidence that peppermint oil can reduce bloating, flatulent and colicky symptoms of irritable bowel syndrome (IBS), with plausible mechanisms of action as an antispasmodic. This benefit extends to children, and more widely in helping children suffering from undifferentiated functional abdominal pain. Inhaling peppermint oil is sufficient to reduce nausea and vomiting.

    Mints are demonstrably cooling. Their constituent menthol has this effect by acting on transient receptor potential (TRP) channels in sensory nerves, effectively stimulating ‘cold receptors’ in the stomach. The consequent cooling is systemic as well as local: for example, peppermint oil not only reduces heartburn faster, but also reduces heart rate and other cardiac consequences of anxiety. The cooling effect may in part explain the symptomatic relief of nasal congestion.

    Topically, peppermint oil is analgesic (pain relieving), and has been shown to be useful in the treatment of neuralgia and pruritis e.g. in shingles, as well as in the relief of headaches.  As a healing agent peppermint gel was shown to be a superior treatment for cracked nipples in breastfeeding mothers.

    Inhaling peppermint oil was found to enhance memory and to increase alertness in healthy volunteers, and may also improve sleep quality.

    In a notable exception to the peppermint oil dominance of the research literature spearmint leaf tea was found to decrease free testosterone and increase luteinizing hormone (LH), follicle-stimulating hormone (FSH) and oestradiol levels in mildly hirsute women, some with polycystic ovary syndrome (PCOS).

  • Did you know?

    After-dinner mints started out as simple home remedies to relieve indigestion: they can still be used for this purpose!

Additional information

  • Safety

    Mint teas and other preparations are very well tolerated by most people. Peppermint and other mint oils are very strong and should be used internally at very low doses if at all. The safest use of oils internally is in enteric-coated capsules to bypass the stomach.

  • Dosage

    6-9 g of dried leaf for therapeutic effect.

  • Constituents

    • Essential oil (0.5–4%) consisting predominantly of menthol (35–45%) and (–)-menthone (10–30%)
    • Tannins (6–12%)
    • Flavonoids primarily eriocitrin, luteolin and hesperidin
    • Triterpenes
    • Bitter substances.

    The most obvious constituent of mints is menthol, responsible for the majority of their therapeutic actions, although the flavonoid and tannin components are also significant. For example the tannins may add to the calming effect of mints in diarrhoea or other irritation of the bowel.

  • Traditional energetics

    • Rasa (taste) Sweet, pungent.
    • Virya (action) Cooling and heating.
    • Vipaka (post-digestive effect) Pungent.
    • Guna (quality) Light, dry, penetrating.
    • Dosha effect: reduces pitta, kapha and vata, in excess aggravates vata
    • Dhatu (tissue) Plasma, blood, nerve.
    • Srotas (channels) Digestive, circulatory, respiratory, nervous.
Mint Peppermint
  • Recipe

    Majestic Mint tea

    When you make this lovely mint tea, the first thing you can feel is the immediate cooling effect of the menthol in the mouth. Then other sensations come through: there are more aromatic, almost pungent flavours as the other volatile oils work through to the palate. As the last sensation you will probably pick up the dryness of the astringent tannins.

    Ingredients:

    As many types of fresh mint as you can find (try peppermint, spearmint, horsemint and fieldmint) 10–20g, about 2 handfuls

    This will serve 2–3 cups of minty tea.

    Method:

    Put all of the ingredients in a pot.
    Add 500ml/18fl oz of freshly boiled filtered water.
    Leave to steep for 5–10 minutes, then strain.
    Some people like a little sweetener with the mint – honey works a treat.


    Let me glow tea

    This delicious recipe is a healing blend of chlorophyll-rich herbs that purify the blood, soothe the liver and cleanse the skin, helping you glow from the inside out. Good for anyone with pimples, acne or other skin blemishes.

    Ingredients:

    • Nettle leaf 3g
    • Fennel seed 2g
    • Peppermint leaf 2g
    • Dandelion root 2g
    • Burdock root 2g
    • Red clover 2g
    • Turmeric root powder 1g
    • Licorice root 1g
    • Lemon juice a twist per cup

    This will serve 2 cups of beautifying tea.

    Method:

    • Put all of the ingredients in a pot (except the lemon). Add 500ml (18fl oz) freshly boiled filtered water.
    • Leave to steep for 10–15 minutes, then strain and add the lemon.

    These recipes are from the book Cleanse, Nurture, Restore by Sebastian Pole

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 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.
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.
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.
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. .
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.
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.
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.

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