Maca

• How It Works

  Maca may increase sexual function but it has not been shown to be effective against cancer.

  Maca has been used traditionally to improve stamina and sexual functioning. Studies have shown that maca may help to increase libido and improve athletic performance. It may also affect some hormone levels in the blood. Further study is warranted.

• Purported Uses
  • To treat infertility
    No clinical trials support this use.
  • To improve sexual performance
    The evidence to support the use of maca in improving sexual function is limited. A few clinical trials showed increase in sexual desire, sperm count, and motility. It may also improve sexual dysfunction cause by antidepressant use or menopause. More studies are warranted.
  • To improve strength and stamina
    A small study suggests it may improve performance in athletes, but more study is needed.
  • To treat cancer
    Scientific evidence is lacking to support this claim.
• Side Effects

  Unverified possible reactions include: altered menstrual cycles, moodiness, cramps, gastritis and insomnia

  Case report

  • Prolonged bleeding outside of regular menstruation and high lab levels of testosterone: A woman in her thirties ingested 1 tsp daily of maca powder dissolved in milk to improve energy and libido. Bleeding began within a few weeks of this regimen and improved after she stopped taking maca. Her high blood levels of testosterone returned to normal 1 month after she stopped taking maca.
• Special Point

  Maca may interfere with lab tests that measure testosterone levels.

• Scientific Name

  Lepidium meyenii, Lepidium peruvianum

• Clinical Summary

  Maca is a nutritionally valuable plant native to Peru that grows in harsh climates above 4,000 feet. It has been used traditionally to enhance fertility and sexual performance in both men and women and to relieve menopausal symptoms ⁽¹⁾. Maca has also been purported to treat cancer and to improve stamina in cancer patients.

  In vitro, maca or its constituents have demonstrated antiviral ⁽¹⁷⁾, antioxidant ⁽¹⁸⁾, anti-inflammatory, analgesic, or neuroprotective ⁽¹⁹⁾ activities.

  Animal studies indicate that maca increases endurance ⁽⁶⁾, enhances sexual function ^(2) (5), and improves scopolamine-induced memory deficits ⁽¹⁴⁾. It also demonstrated antidepressant ⁽²⁰⁾ and postmenopausal hormone-modulating ⁽²¹⁾ effects.

  Only a few small trials have evaluated maca for its effects in humans. Maca consumption was associated with lower serum IL-6 levels and higher health status ⁽²²⁾. In men, maca supplementation increased libido ⁽³⁾, sperm production and motility ⁽⁴⁾, and enhanced subjective sexual well-being ⁽¹¹⁾. Another preliminary study suggests it may also improve athletic performance ⁽²³⁾. In women, several studies suggest that maca improves both antidepressant- and menopause-induced sexual dysfunction ^{(12) (24) (25) (26)}. A study in Chinese postmenopausal women showed neither hormonal nor immunological effects, but did appear to reduce depressive symptoms and diastolic blood pressure ⁽²⁷⁾. However, systematic reviews have deemed the evidence on maca for sexual dysfunction ^{(13) (28) (29)} or for alleviating menopausal symptoms ⁽¹⁵⁾ to be limited and requiring further research. Another review indicates that maca is not an effective anti-aging agent ⁽¹⁶⁾.

  A case report showed maca may interfere with testosterone immunoassays ⁽³⁰⁾.

• Purported Uses
  • Infertility
  • Menopausal symptoms
  • Sexual performance
  • Strength and stamina
  • Cancer treatment
• Mechanism of Action

  Maca contains glucosinolates, mostly benzylglucosinolate, along with hydroxy or methoxylated benzyl derivatives and tryptophan-derived compounds, and depending on the phenotype (red, yellow, purple or black) may be associated with different biological effects ⁽³¹⁾.

  In vitro, both methanolic and aqueous extracts of maca exhibit estrogenic activity ⁽¹⁰⁾. A methanol maca extract demonstrated antiviral activity against Flu-A and Flu-B viruses ⁽¹⁷⁾. An isolated N‑alkylamide from maca root was found to possess both direct and indirect cannabimimetic actions ⁽³²⁾. Maca polysaccharides demonstrated radical scavenging activity ⁽¹⁸⁾. Macamides, normally not present in fresh plants but introduced during traditional drying practices ⁽³¹⁾, are fatty acid amide hydrolase (FAAH) inhibitors, and act on the central nervous system by modulating the release of neurotransmitters ⁽¹⁹⁾. Antidepressant-like effects were associated with activation of both noradrenergic and dopaminergic systems and attenuation of oxidative stress ⁽²⁰⁾.

  In animal models, maca powder derived from tubers enhanced serum luteinizing hormone (LH) levels in female rats during the proestrus LH surge in a dose-dependent manner, suggesting it may enhance fertility ⁽³³⁾. In postmenopausal models, maca modulates hormone levels particularly by decreasing follicle-stimulating hormone (FSH) levels ⁽²¹⁾.

  In humans, although maca does not affect serum levels of LH, FSH, prolactin, testosterone, or estradiol in men ^(4) (9), it appears to modulate some hormone levels in women in some studies ^(24) (26) but not others ^(25) (27). Increased LH and decreased FSH that corresponded with improved sexual functioning in postmenopausal women are potentially attributed to a negative feedback loop, resulting in increased androgen production ^(24) (26). It may also exert androgenic effects at the testosterone receptor on target organs without affecting testosterone or gonadotrophin levels ^(24) (30). At the same time, the benefits of maca for antidepressant-induced sexual dysfunction in women may be more a function of advancing age rather than menopausal status, as there was no correlation with estrogen levels ⁽²⁴⁾.

• Adverse Reactions

  Subjective reports of altered menstrual cycles, moodiness, cramps, gastritis, and insomnia ⁽³⁴⁾.

  Flu-like symptoms and vomiting report were reported in one clinical study. However, it is unclear if these were caused by maca ⁽²⁴⁾.

  Case report

  Prolonged intermenstrual bleeding and markedly elevated total plasma testosterone: In a white female in her thirties from ingesting maca powder 1 tsp daily dissolved in milk to improve energy levels and libido ⁽³⁰⁾.

• Herb Lab Interactions

  Maca may interfere with testosterone immunoassays ⁽³⁰⁾.

• References

  1. Muhammad I, Zhao J, Dunbar DC, Khan IA. Constituents of Lepidium meyenii ’maca’. Phytochemistry 2002;59:105-10.

  2. Zheng BL, He K, Kim CH, Rogers L, Shao Y, Huang ZY et al. Effect of a lipidic extract from lepidium meyenii on sexual behavior in mice and rats. Urology 2000;55:598-602.

  3. Gonzales GF, Cordova A, Vega K, Chung A, Villena A, Gonez Cet al. Effect of Lepidium meyenii (MACA) on sexual desire and its absent relationship with serum testosterone levels in adult healthy men. Andrologia 2002;34:367-72.

  4. Gonzales GF, Cordova A, Gonzales C, Chung A, Vega K, Villena A. Lepidium meyenii (Maca) improved semen parameters in adult men. Asian J Androl 2001;3:301-3.

  5. Cicero AF, Piacente S, Plaza A, Sala E, Arletti R, Pizza C. Hexanic Maca extract improves rat sexual performance more effectively than methanolic and chloroformic Maca extracts. Andrologia 2002;34:177-9.

  6. Balick MJ,.Lee R. Maca: from traditional food crop to energy and libido stimulant. Altern Ther Health Med 2002;8:96-8.

  7. Li G, Ammermann U, Quiros CF. Glucosinolate Contents in Maca (Lepidium peruvianum chacon) Seeds, Sprouts, Mature Plants and Several Derived Commercial Products. Economic Botany 2001;55:255-62.

  8. Piacente S, Carbone V, Plaza A, Zampelli A, Pizza C. Investigation of the tuber constituents of maca (Lepidium meyenii Walp.). J Agric Food Chem. 2002;50:5621-5.

  9. Gonzales GF, Cordova A, Vega K, et al. Effect of Lepidium meyenii (Maca), a root with aphrodisiac and fertility-enhancing properties, on serum reproductive hormone levels in adult healthy men. J Endocrinol 2003;176(1):163-8.

  10. Valentova K, Buckiova D, Kren V, et al. The in vitro biological activity of Lepidium meyenii extracts. Cell Biol Toxicol 2006;22(2):91-9.

  11. Zenico T, Cicero AF, Valmorri L, Mercuriali M, Bercovich E. Subjective effects of Lepidium meyenii (Maca) extract on well-being and sexual performances in patients with mild erectile dysfunction: a randomised, double-blind clinical trial. Andrologia. 2009 Apr;41(2):95-9.

  12. Dording CM, Fisher L, Papakostas G, et al. A double-blind, randomized, pilot dose-finding study of maca root (L. meyenii) for the management of SSRI-induced sexual dysfunction. CNS Neurosci Ther. 2008 Fall;14(3):182-91.

  13. Shin BC, Lee MS, Yang EJ, Lim HS, Ernst E. Maca (L. meyenii) for improving sexual function: a systematic review. BMC Complement Altern Med. 2010 Aug 6;10:44.

  14. Rubio J, Dang H, Gong M, et al. Aqueous and hydroalcoholic extracts of Black Maca (Lepidium meyenii) improve scopolamine-induced memory impairment in mice. Food Chem Toxicol. 2007 Oct;45(10):1882-90.

  15. Lee MS, Shin BC, Yang EJ, Lim HJ, Ernst E. Maca (Lepidium meyenii) for treatment of menopausal symptoms: A systematic review. Maturitas. 2011 Nov;70(3):227-33.

  16. Hunt KJ, Hung SK, Ernst E. Botanical extracts as anti-aging preparations for the skin: a systematic review.Drugs Aging. 2010 Dec 1;27(12):973-85.

  17. Del Valle Mendoza J, Pumarola T, Gonzales LA, et al. Antiviral activity of maca (Lepidium meyenii) against human influenza virus. Asian Pac J Trop Med. Sep 2014;7s1:S415-420.

  18. Zha S, Zhao Q, Chen J, et al. Extraction, purification and antioxidant activities of the polysaccharides from maca (Lepidium meyenii). Carbohydr Polym. Oct 13 2014;111:584-587.

  19. Almukadi H, Wu H, Bohlke M, et al. The macamide N-3-methoxybenzyl-linoleamide is a time-dependent fatty acid amide hydrolase (FAAH) inhibitor. Mol Neurobiol. Oct 2013;48(2):333-339.

  20. Ai Z, Cheng AF, Yu YT, et al. Antidepressant-like behavioral, anatomical, and biochemical effects of petroleum ether extract from maca (Lepidium meyenii) in mice exposed to chronic unpredictable mild stress. J Med Food. May 2014;17(5):535-542.

  21. Zhang Y, Yu L, Jin W, et al. Effect of ethanolic extract of Lepidium meyenii Walp on serum hormone levels in ovariectomized rats. Evid Based Complement Alternat Med. Jul-Aug 2014;46(4):416-419.

  22. Gonzales GF, Gasco M, Lozada-Requena I. Role of maca (Lepidium meyenii) consumption on serum interleukin-6 levels and health status in populations living in the Peruvian Central Andes over 4000 m of altitude. Plant Foods Hum Nutr. Dec 2013;68(4):347-351.

  23. Stone M, Ibarra A, Roller M, et al. A pilot investigation into the effect of maca supplementation on physical activity and sexual desire in sportsmen. J Ethnopharmacol. Dec 10 2009;126(3):574-576.

  24. Dording CM, Schettler PJ, Dalton ED, et al. A double-blind placebo-controlled trial of maca root as treatment for antidepressant-induced sexual dysfunction in women. 2015;2015:949036.

  25. Brooks NA, Wilcox G, Walker KZ, et al. Beneficial effects of Lepidium meyenii (Maca) on psychological symptoms and measures of sexual dysfunction in postmenopausal women are not related to estrogen or androgen content. Menopause. Nov-Dec 2008;15(6):1157-1162.

  26. Meissner HO, Kapczynski W, Mscisz A, et al. Use of gelatinized maca (Lepidium peruvianum) in early postmenopausal women. Int J Biomed Sci. Jun 2005;1(1):33-45.

  27. Stojanovska L, Law C, Lai B, et al. Maca reduces blood pressure and depression, in a pilot study in postmenopausal women. Climacteric. Feb 2015;18(1):69-78.

  28. Ernst E, Posadzki P, Lee MS. Complementary and alternative medicine (CAM) for sexual dysfunction and erectile dysfunction in older men and women: an overview of systematic reviews. Maturitas. Sep 2011;70(1):37-41.

  29. Lee MS, Shin BC, Yang EJ, et al. Maca (Lepidium meyenii) for treatment of menopausal symptoms: A systematic review. Maturitas. Nov 2011;70(3):227-233.

  30. Srikugan L, Sankaralingam A, McGowan B. First case report of testosterone assay-interference in a female taking maca (Lepidium meyenii). BMJ Case Rep. 2011;2011.

  31. Esparza E, Hadzich A, Kofer W, et al. Bioactive maca (Lepidium meyenii) alkamides are a result of traditional Andean postharvest drying practices. Phytochemistry. Aug 2015;116:138-148.

  32. Hajdu Z, Nicolussi S, Rau M, et al. Identification of endocannabinoid system-modulating N-alkylamides from Heliopsis helianthoides var. scabra and Lepidium meyenii. J Nat Prod. Jul 25 2014;77(7):1663-1669.

  33. Uchiyama F, Jikyo T, Takeda R, et al. Lepidium meyenii (Maca) enhances the serum levels of luteinising hormone in female rats. J Ethnopharmacol. Feb 3 2014;151(2):897-902.

  34. Corazza O, Martinotti G, Santacroce R, et al. Sexual enhancement products for sale online: raising awareness of the psychoactive effects of yohimbine, maca, horny goat weed, and Ginkgo biloba. Biomed Res Int. 2014;2014:841798.