Native to the Mediterranean area, but now common throughout the world, spearmint (Mentha spicata, Lamiaceae) is a hardy, perennial herb with bright green, sharp-toothed leaves and pink or lilac spiked flowers.¹ While used as a culinary herb worldwide, the ancient Greeks scented their bathwater with spearmint as well as consuming it orally as a restorative. The Romans introduced the herb to Great Britain where it was used to keep milk from curdling.² During the Medieval period, spearmint became a staple in oral hygiene to promote healthy gums and to whiten teeth. A tonic water of spearmint can relieve colic, digestive problems, hiccups, and nausea.¹ Culpeper applied spearmint to the forehead to ease headaches and used it for children "against all manner of breakings out, sores or scabs."³ Besides the aforementioned uses, both western and eastern medicines have used the herb as a stomachic, antiseptic, anesthetic, and stimulant.² It can also be used as an insecticide and emmenagogue. An essential oil is obtained from steam distillation of the flowering tops. The yellow to olive colored oil has a green, spicy-herb, minty scent. Constituents include L-carvone, limonene, menthone, menthol, and pinenes.

The essential oil is considered milder than peppermint (M. × piperita), and, therefore, may be more appropriate for children. Along with digestive issues, spearmint oil can be used to relieve mental strain, fatigue, stress, as a decongestant, and to treat acne and congested skin. It is thought to be non-sensitizing, non-irritant, and non-toxic.

In a randomized, controlled trial (RCT) of children undergoing colonoscopy, 0.4 mL spearmint essential oil (SEO) led to improvements in self-rated measures of pain (P<0.05). In a RCT of pregnant women undergoing Caesarean section, 0.12 mL SEO administered in three equal doses over 60 minutes led to significantly reduced levels of pain. A combination of SEO and celery (Apium graveolens, Apiaceae) oil, applied topically, was shown to reduce symptoms of osteoarthritis. An enriched spearmint infused beverage ("tea") standardized for rosmarinic acid was investigated in a 16-week RCT in patients with osteoarthritis. Six hundred mL of a spearmint, containing 280 mg rosmarinic acid, or a spearmint tea, containing a low level of rosmarinic acid (26 mg), taken twice daily led to improvements in stiffness and disability scores for both groups. However, pain scores were reduced only in the high-rosmarinic acid group. ⁴

References

¹Lawless J. The Encyclopedia of Essential Oils. San Francisco, CA: Conari Press; 2013.

²Battaglia S. The Complete Guide to Aromatherapy, 2^nd edition. Brisbane: The International Centre of Holistic Aromatherapy; 2003.

³Culpeper N. Culpeper’s Complete Herbal. London: Richard Evans; 1814.

Lori Glenn,  Managing Editor