Spearmint Enhances Brain Function and Memory

Spearmint (Mentha spicata syn. Mentha viridis) is a variety of mint original to Eurasia now naturalized throughout temperate regions of the world, particularly North America, South America and Africa. It is widely cultivated in Morocco, where it is used in generous amounts to flavor local dishes and, most notably, traditional Moroccon mint tea (also called Maghrebi mint tea). Spearmint is also a key ingredient in several other well-known drinks, such as the mint julep, the mojito and southern sweet tea. Also known as common mint, garden mint, lamb mint, mackeral mint, Our Lady's mint and Sage of Bethlehem, spearmint is the “mother” mint from which many hybrids have been developed, including the notable but not-as-sweet peppermint.

The herb contains a number of active constituents , including cineol, limonene, dihydrocarvone, rosmarinic acid and a small amount of menthol. Collectively, these compounds exert powerful antispasmodic, antibacterial, antifungal and antioxidant benefits. Historically, the infused herb (tea), liquid extracts and essential oil of spearmint have been used to treat cramps, upset stomach, nausea, toothache, sore throat, headache, arthritis and stress.

Spearmint appears abundantly in the pages of many old herbals, especially in those of early English botanists, physicians and herbalists. John Parkinson (1567–1650) wrote that “Mintes are sometimes used in Baths with Balm and other herbs as a help to comfort and strengthen the nerves and sinews. It is much used either outwardly applied or inwardly drunk to strengthen and comfort weak stomackes.” Gerard declared that spearmint is “…good against watering eies and all manner of breakings out on the head and sores. It is applied with salt to the bitings of mad dogs.... They lay it on the stinging of wasps and bees with good success.” Culpepper suggested applying a brew of spearmint and vinegar as “an excellent wash to get rid of scurf (i.e., dandruff)” and that the herb, “Being smelled into it is comfortable for the head and memory, and a decoction when used as a gargle, cures the mouth and gums.”

Clearly, the wisdom of the early herbalists regarding the virtues of spearmint has held up in the modern era since the herb is widely used in the food, cosmetic and pharmaceutical industries today. Recently, scientists have become particularly interested in studying the effects of the phenolic compounds in the herb, most notably rosmaric acid, on cognitive function and memory. In fact, some preliminary studies indicate that rosmaric acid may promote neurogenesis – the generation of new cells – in the hippocampus region of the brain, where working memory resides. (1) It appears that rosmarinic acid and other phenolic compounds in spearmint also protect existing brain cells by inhibiting acetylcholinesterase, an enzyme that would otherwise facilitate the breakdown of acetylcholine, a neurotransmitter involved in memory. (3,4)

References

1. Fonseca BA, Herrlinger KA. The effects of a proprietary spearmint extract on neurogenesis rates in rat hippocampal neurons. Paper presented at: Neuroscience2016; San Diego, CA.https://www.prnewswire.com/news-releases/study-shows-neumentix-enhances-new-nerve-cell-growth-in-rat-hippocampal-cells-300361070.html

2. Farr SA, Niehoff ML, Ceddia MA, et al. "Effect of botanical extracts containing carnosic acid or rosmarinic acid on learning and memory in SAMP8 mice." Physiol Behav. 2016 Oct 15;165:328-38.https://www.ncbi.nlm.nih.gov/pubmed/27527000

3. Ali-Shtayeh MS, Jamous RM, Zaitoun SYA, et al. “In-vitro screening of acetylcholinesterase inhibitory activity of extracts from Palestinian indigenous flora in relation to the treatment of Alzheimer’s disease.” Functional Foods in Health and Disease. 2014;4(9):381-400.https://www.semanticscholar.org/paper/In-vitro-screening-of-acetylcholinesterase-activity-Ali-Shtayeh-Jamous/9c88425a75a4544e3042f230420fe2c40c27e600

4. Oinonen PP, Jokela JK, Hatakka AI, et al. “Linarin, a selective acetylcholinesterase inhibitor from Mentha arvensis.” Fitoterapia. 2006;77(6):429-34.https://www.sciencedirect.com/science/article/pii/S0367326X06001171?via%3Dihub