Spearmint: food uses, nutrition and the evidence on hormones

Which mint, and which form?

Spearmint is Mentha spicata L., an aromatic perennial in the mint family, Lamiaceae. Its pointed, toothed leaves are used fresh or dried in food. It is a different plant from peppermint, Mentha × piperita. A packet labelled only “mint” may therefore need a closer look at the species and ingredients. This article concerns spearmint leaves and leaf infusions; it does not treat every mint-flavoured product as the same preparation. [1] [2]

The leaves contain aromatic compounds; carvone is an important component of spearmint oil and its characteristic flavour. The whole leaf, a strained infusion, a concentrated extract and an essential oil are not interchangeable. Their composition and exposure differ, so evidence about one cannot simply establish a benefit or a dose for another. [9] [11]

Nutrition in a realistic herb quantity

The following estimates are for 5 g of fresh edible leaves, a small weighed amount used for flavour. They were calculated by multiplying the USDA laboratory database values per 100 g by 0.05 and rounding. This is an illustrative food portion, not a recommended daily or medicinal dose. [3]

Nutrient	In 5 g of fresh leaves
Energy	2.2 kcal
Protein	0.16 g
Total carbohydrate	0.42 g
Dietary fibre	0.34 g
Fat	0.04 g
Iron	0.59 mg
Calcium	10 mg
Potassium	23 mg
Folate	5 µg
Vitamin C	0.7 mg

These are reference estimates, not an analysis of each bunch. A few leaves weigh much less than a large herb salad, and dried leaves have lost water. The table cannot be assigned to a cup of strained tea: discarding the leaves removes most of the solid plant material, including its fibre. Nor does the iron listed equal the amount absorbed. [3]

Spearmint's clearest everyday benefit is flavour with little energy in a small portion. It can make vegetables, beans, yoghurt or water more appealing and broaden the flavours in ordinary meals. Try chopped leaves with cucumber and plain yoghurt, peas, a bean salad or a fruit salad. These are culinary uses, not demonstrated treatments. Adding plenty of sugar, syrup or sweetened yoghurt changes the nutritional result; mint does not cancel those ingredients. [2] [1] [3]

Choosing, preparing and storing it

Buy leaves intended for food, with a clear identity and a fresh aroma. Discard spoiled, mouldy or badly damaged material. Rinse under running water, remove unwanted stems and debris, and drain or pat dry. Soap, bleach and household cleaning products are unnecessary. Chop shortly before use to retain aroma. Fresh or dried food-grade leaves can be infused in hot water and strained; adjust the flavour to preference or follow the food product's instructions. A study's twice-daily tea schedule is not a personal prescription. [4] [2]

Store fresh mint dry and covered in the refrigerator; Illinois Extension gives about one week for refrigerated leaves. Check its condition and use it sooner if quality declines. For longer storage, pat rinsed leaves dry, freeze them in a single layer, then transfer to a labelled freezer bag. Texture changes after freezing, so they often suit cooked dishes or infusions better than garnishes. Dry leaves with a suitable herb-drying method and good ventilation, avoiding large damp bunches that can mould. When leaves crumble, keep them airtight, cool, dry and dark; Maryland Extension suggests using dried herbs within 6 months. [2] [4]

A mint and yoghurt sauce or another perishable prepared dish still needs safe chilling. Put it in a refrigerator held at 4 °C or colder within 2 hours, or within 1 hour when the surrounding temperature exceeds 32 °C. Use shallow containers for cooked leftovers. The herb's aroma does not preserve an otherwise perishable meal. [5]

Tolerance, allergy and essential oils

If a particular amount or product repeatedly causes heartburn or abdominal discomfort, stop that trigger. Spearmint should not be assumed to behave exactly like peppermint, and a pleasant sensation after tea does not establish treatment of reflux or irritable bowel syndrome. The spearmint-specific reflux study is discussed below. [8]

Contact allergy to carvone, a mint flavour used in oral-care products as well as foods, is documented. A Swedish retrospective study found positive patch tests among patients referred for testing, often with oral or lip-area symptoms. This selected clinical group does not tell us the frequency of allergy among ordinary spearmint eaters. Recurrent mouth irritation, lip eczema or a rash after a mint-flavoured product deserves assessment; the responsible ingredient should be identified rather than assuming that every such product is equivalent. [9]

Avoid a product that has caused a confirmed allergic reaction. New tongue or throat swelling, breathing difficulty or collapse after eating requires emergency help. Persistent contact irritation and an immediate severe allergic reaction are different problems, even though both merit attention. [10]

Do not use a bottle of essential oil as a replacement for leaves in a drink or as a home treatment for a child. Concentrated oils can irritate tissues, and aspiration into the lungs can cause serious injury. Keep them out of children's reach and obtain poison-centre advice promptly after accidental ingestion. Culinary flavourings manufactured for a specified food use must be used according to their own instructions; a fragrance or topical oil is not a food ingredient. [11]

Medicines, pregnancy, breastfeeding and children

The cited human studies do not establish a specific clinical interaction between an ordinary culinary portion of spearmint and a named medicine. This limited finding does not prove that every extract is interaction-free. If you plan sustained tea or extract use for a hormonal purpose, show the product and intended amount to your pharmacist or treating clinician, particularly during fertility treatment or while using hormonal or antiandrogen medicines. The relevant concern is that small tea studies changed hormone measurements while combinations with these treatments were not established. Do not stop prescribed treatment because of a tea claim. [6] [7]

Pregnancy or trying to conceive: a little leaf used to flavour food is a different exposure from a self-prescribed antiandrogen regimen. The short trials below do not establish pregnancy safety, improved ovulation or fertility outcomes. Do not use them as a reason to begin medicinal amounts while pregnant or trying to conceive without an individual review. This is a limit in the evidence, not a claim that normal food use causes miscarriage. [7] [6]

Breastfeeding: the studies cited here do not establish either increased or reduced milk supply from spearmint, or the safety of concentrated maternal supplementation for the infant. There is no basis here for a blanket ban on small culinary quantities. A suspected feeding problem should be assessed directly instead of treating it with large amounts of mint or assuming the herb is the cause. [6] [7]

Children: once complementary foods are appropriate, generally around 6 months with developmental readiness, a little finely chopped leaf can be used for flavour in an appropriate food texture. Do not apply an adult research schedule to a child. Mint tea does not replace breastmilk or formula, and honey should not be added to anything given during the first year. Keep drinks cool enough to avoid scalding and concentrated oils away from children. [12] [11]

Claims: what does the evidence say?

“Spearmint tea removes unwanted hair and cures PCOS”

Verdict: a preliminary hormonal signal, not an established treatment. An earlier study involved 21 women with hirsutism, including 12 with PCOS and 9 with idiopathic hirsutism. They drank spearmint tea twice daily for 5 days. Free testosterone fell, but total testosterone and DHEAS did not significantly decrease; some other hormone measurements rose. Five days cannot establish lasting changes in hair growth. [6]

A later 30-day randomized trial assigned 42 participants to twice-daily spearmint tea or a placebo herbal tea; 41 completed it. Free and total testosterone decreased in the spearmint group and participants reported improvement, but the objective Ferriman–Gallwey hair score did not significantly improve compared with the control group. The short duration leaves an important question open; it does not prove that longer treatment works. Neither study establishes a fertility cure, and a hormone result is not the same as a patient-important outcome. [7]

“All mint tea reliably treats reflux or digestive disease”

Verdict: this is not established for spearmint leaves. A randomized crossover study in healthy volunteers compared flavouring and high doses of spearmint with placebo. During brief monitoring, lower oesophageal sphincter pressure and reflux episodes did not significantly change, while the high dose produced more symptoms. It was an acute physiological experiment, not a treatment trial of ordinary tea in people with chronic reflux or irritable bowel syndrome. Individual comfort may justify a preferred drink, but it should not delay assessment of persistent symptoms. [8]

“Because spearmint contains iron, a few leaves or mint tea treat anaemia”

Verdict: nutrient content does not establish treatment. The 5 g example provides only 0.59 mg of iron, before considering absorption, and a strained infusion is not the same food portion. A composition table reports what a sample contains; it does not show correction of iron deficiency or another cause of anaemia. Spearmint can flavour a varied diet, but suspected anaemia needs its cause identified and appropriate treatment. [3]

“Essential oil in water is simply a stronger version of leaf tea”

Verdict: incorrect. An essential oil is a concentrated volatile fraction with different exposure and safety issues. Adding drops to water does not recreate the composition or research evidence of a leaf infusion. Its pleasant smell and natural origin do not remove the ingestion and aspiration risks. Use food leaves for culinary infusions and keep non-food oils out of drinks. [11]

Conclusion

Spearmint earns its place in food through aroma, versatility and the small amounts needed to change a dish's flavour. Use clean, correctly identified leaves, keep prepared foods properly chilled and choose a portion that agrees with you. The hormonal findings are interesting but still fall short of proving reliable hair reduction or a fertility benefit. Keeping ordinary food, leaf tea and concentrated products distinct makes the evidence easier to use without turning an enjoyable herb into an unsupported treatment.