Spearmint or mentha spicata is a herbaceous, rhizomatous, perennial plant native to most of Europe and Southwest Asia and widely spread throughout other countries due to broad cultivation for culinary and medicinal use. It grows to between 30 – 100 cm tall and wide from a fleshy underground rhizome which spreads readily. For this reason many gardeners prefer to grow it in a pot. The foliage and stems of the plant are sometimes smooth or hairy and the leaves are between 5 – 9 cm long and 1.5 – 3 cm broad and have a serrated margin culminating in a pointed tip, giving the herb its name. Flowers, 2.5 – 3mm long and broad, are produced in clusters on slender spikes and may be pink, white or blue. Whilst spearmint will tolerate almost any condition, it prefers a partly shaded aspect with good quality loamy soil with plenty of organic matter. The leaves are most aromatic prior to flowering, so if you grow spearmint yourself it is best to harvest the leaves before the plant flowers and dry them.
Two studies in the last 5 years have concluded that regular consumption of spearmint tea promptly affects serum testosterone levels. One heaped teaspoonful of the herb, roughly equal to 5 grams, steeped in one cup of boiling water for between 5 and 10 minutes, taken twice a day showed positive results by blood testing after just 5 days. Unfortunately, this was as long as the first study on this subject lasted and the second more recent study was only a little longer at 30 days. Whilst it is reasonable to assume that a reduction in serum testosterone will eventually result in reduced hirsutism, due to the hair growth cycle clinical results would not be likely in less than 3 and possibly up to 6 months. Hopefully in the future we will see the results of studies that continue for long enough to show clinical results.
Other benefits of spearmint consumption include lower triglyceride levels and potentially a lowered risk of certain types of cancer such as breast, colon, lung and pancreas through inhibition of heterocyclic amines (mutagenic compounds produced when muscle meats are cooked at high temperatures). Prostate cancer risk has also been linked to the consumption of heterocyclic amines, though thankfully this is one problem women with PCOS don’t need to worry about for themselves. If you have any prostate-owning people near and dear to you who like a good barbeque or fry up every now and then, it may be worth suggesting they consume a cup of spearmint tea with the meal, or use spearmint to flavour the meat. Spearmint has also been shown to have excellent antioxidant activity and has been found to delay the oxidation of fats. After 4 weeks in chilled storage, irradiated lamb which contained spearmint extract was found to have half the oxidation products of lamb not treated with spearmint extract.
In the initial Turkish study, blood test results showed a significant changes in several hormones. Free testosterone was reduced by just over 30%, luteinising hormone (LH) the hormone responsible for triggering ovulation when it surges mid-cycle was increased by around 30%, follicle stimulating hormone (FSH) the hormone responsible for the proper maturation of ovarian follicles was increased by around 15%, and oestradiol by 35%. No significant change in total testosterone levels were noted. Triglycerides also decreased by 10%. As the tea was given to participants in this study during the first half or follicular phase of their menstrual cycle, these hormonal changes could have a positive effect on ovulation.
In the more recent UK study free testosterone decreased by around 30% by Day 15 with only a very slight further decrease at Day 30, total testosterone had not decreased significantly by Day 15, however, by Day 30 it had reduced by almost 20%. LH levels increased by almost 40% by Day 30 and FSH by around 20%. No significant change was seen in DHEAS levels.
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