Maca: family, products, uses, evidence, dosage, side effects, interactions

Maca: family, products, uses, evidence, dosage, side effects, interactions

What is Maca?

Maca or lat. Lepidium meyenii is a biennial herbaceous plant of the family Brassicae which is cultivated in the Andes, mainly in the highlands of Peru. It has been used for over 2000 years in the region as food and medicine. It has been used traditionally in the Andes as a general tonic, for anaemia, infertility and female hormone balance. There are different types of maca (eight or more different ecotypes) with different colours ranging from white to black, with the yellow one being the most common cultivar in the Andes. Recently, it has been introduced to Western countries, but there is considerable concern about the quality and composition of maca products as different  maca ecotypes (with differently coloured hypocotyls) appear to differ in their biological effects. However, the planting site appears to be the most important factor affecting chemical variation.

Maca family, other names, origin, and botanical drug used

Family: Brassicaceae (Cruciferae)

Other names: Chilque; macaia; Peruvian ginseng

Origin: Maca is mainly domesticated in the central Andes of Peru at elevations of 3500–4500 m above sea level, a zone characterized by areas of barren, rocky terrain, intense sunlight, fierce winds, and freezing temperatures. In this inaccessible and intensely cold habitat, few other crops survive with the exception of some highland grasses, and a few hardy members of the Solanaceae. Domesticated maca has been grown in Peru for at least 2000 years ago, but little is known about its origin. There are eight or more different ecotypes in the cultivation area, distinguished according to the color of their roots, such as, yellow, purple, white, grey, black, yellow/purple and white. The yellow ecotype is the commonest cultivar in this region. The subterranean part (hypocotyls) of maca is edible, and is a staple food for the indigenous peoples of this arid zone. Maca ‘hypocotyls’ are eaten fresh, or can be dried and stored for later consumption. The dried roots can be eaten after boiling in water or milk, or made into juices, cocktails, alcoholic beverages or maca coffee

Botanical drug used: Dried powdered ‘root’ (hypocotyl)

Maca’s chemical composition and main compounds

Main compunds of Maca plant are: unsaturated fatty acids, mainly macaene and macamide, as well as linoleic and oleic acids, the glucosinolates glucotropaeolin and m-methoxyglucotropaeolin, alkaloids including lepidiline A, lepidiline B and macaridine, and sterols such as β-sitosterol, campesterol and stigmasterol. The root is rich in minerals and trace elements.

Macaene and macamide: Different secondary metabolites have been found in maca root. The typical compounds that can be found in maca are macaene and macamide. These novel polyunsaturated fatty acids and their amides are unique and are not found in other plants. It has been suggested that macaene and macamide be the group of biologically active components in maca involved in improving sexual performance. The contents of these specific compounds may vary widely in different maca samples. In dried maca, macaene may range from around 0.09–0.45%, and macamide ranges from 0.06% to 0.52%. One macaene and sixteen types of macamide have been found up to now.

Maca's chemical composition and main compounds

What does maca powder do for you?
Macaene and macamide strucutures

Glucosinolates and their derivatives: Glucosinolates of maca, and their derived products, have received important scientific attention because of their biological activities, particularly their ability to combat pathogens and cancer. They are widely distributed in cruciferous crops, and are considered largely responsible for the distinctive, pungent flavor of maca. There are nine kinds of glucosinolates found in maca and most of them are aromatic glucosinolates. The amount of glucosinolates that can be found in fresh maca is about 1% which is about 100 times more that can be found in cruciferous crops such as cabbage, cauli- flower and broccoli. The content and type of glucosinolates in maca present differ in various organs of the plant, such as seeds, sprouts, but also varies according to plant age. In maca, the total content of glucosinolates is highest in fresh hypocotyls, followed by the sprouts, seeds, then dried hypocotyls, and fresh leaves. Glucosinolate can be hydrolyzed to a series of different compounds, such as iosthiocyanate, thiocyanate and nitriles by the endogenous enzyme, myrosinase. In the intact cells, glucosinolates are separated from myrosinase. But, when the cells are damaged, glucosinolates can be easily broken down by this enzyme. This is the main reason why dried maca roots or processed products have much lower glucosinolates content than fresh tissue and seeds.

Alkaloids: Alkaloids are mainly found in nature amongst the members of the plant kingdom, though some fungi also naturally secrete these compounds. They are generally classified into about 60 different kinds according to their basic structures. Most alkaloids show some form of biological activities. Three alkaloids have been isolated from maca roots: two imidazole alkaloids (lepidiline A and lepidiline B) and one benzylated derivative of 1,2-dihydro-N-hydroxypyridine (macaridine).

Sterols: Many types of phytosterols have been isolated from maca. Phytosterols are bioactive compounds found in all vegetable foods. In exhibit anti-cancer, anti-inflammatory and anti-oxidatant properties.

Maca indications and uses

  • Popularly, it is used as a tonic and as an aphrodisiac to enhance sexual drive and female fertility.
  • Managing menopausal symptoms.

Maca evidence of efficacy and mechanism of action

The evidence from clinical studies to support its use as an aphrodisiac is very limited, although there is some evidence for its use in managing menopausal symptoms. Further studies are needed before any recommendation can be made.

A systematic review on the use of maca for treatment of menopausal symptoms, which included four double-blind randomised placebo-controlled clinical trials in healthy peri-menopausal, early post-menopausal and late post-menopausal women, showed that there is limited evidence to support its use, and that further studies are needed. However, based on these studies, maca was considered to be more effective than a placebo. Its effect on improving sexual function was also assessed in a systematic review. Again, the evidence available to support its effects on the treatment of sexual function in healthy volunteers (men and women) and men with sexual dysfunction was limited.

The mechanisms of maca action are unknown. It has been proposed that the polyunsaturated fatty acids (macaene and macamide), the glucosinolates, and the alkaloid macaridine are the compounds responsible for its biological activity. Pre-clinical studies suggest that maca may improve sperm count and motility and enhance fertility, and it improved sexual performance in rats, although the mechanism is not clear. Maca has antioxidant and free radical scavenging effects and a high nutritional content, which might help to promote vitality. The phytosterols may have an effect on menopause symptoms, as shown in ovariectomised rats studies.

Maca side effects

Overall, considered to be safe, as the root is also used as a vegetable, but further studies are needed to confirm its safety. Despite the limited clinical studies on its efficacy and safety, it is widely marketed over the Internet for its purported beneficial effects on sexual function and menopausal symptoms.

Maca’s interactions

There are no-known interactions between maca prodcuts and other drugs. Although, further studies are needed.

Maca contraindications

Not recommended during pregnancy and lactation due to lack of safety data.

Maca dosage

For products, as recommended by the manufacturer. The optimum dose of maca is unknown
but doses up to 3500 mg/day have been used.

Maca use for fertility improvement

In the formation of the Inca Empire, maca was used to improve fertilities of both humans and their livestock. This was thought to be essential because fertility rates were generally considered to be much weakened at high altitude. Now the effects of maca have been scientifically examined using the rat model. Administration of maca was found to prevent the reduction in both body weight and epididymal sperm count induced by high altitude and also to reduce the deleterious effect of malathion or lead acetate on spermatogenesis in rats. Examinations on normal male rats treated with maca extracts showed significantly increased epididymal sperm counts and spermatids, and higher testicular and epididymis weights. These effects were dose-dependent.

Maca has also been shown to have the same effects in humans. It was found that oral administration of maca tablets to normal adult men over a period of 4 months, led to seminal volume increasing, sperm count per ejaculum increasing and motile sperm count increasege. These semen variables following the oral administration of maca for the period of 4 months were significantly different from those on the test group prior to administration. Maca has also been shown to improve the fertility in females. Oral administration of maca extract to mice, led to increased litter size and pregnancy rates in adult female mice . The mechanism of maca improving fertility of male and female is not yet fully elucidated. Some studies have shown that maca extracts exhibited estrogenic activity, which led MCF-7 cells, a estrogen-positive cell line, to proliferate in vitro and also to increased uterine weight in rats. The effects of estrogenic activity of maca may be partly due to the content of phytosterols in the extracts. This estrogenic activity of maca may help explain the means by which it improves female fertility. Earlier studies showed that the role of estrogens in both spermatogenesis and sexual desire in man is complex. Estrogens are important to males as well as to females and they have been proposed that they should be considered as ‘male hormones’.

Maca as an aphrodisiac

Within the Andean region maca is widely held in high repute as an aphrodisiac for both men and women.

Rat and mouse models have been used to assess the validity of this claimed effect. It was found that oral administration of maca extracts improved the copulatory performance of sexually inexperienced male mice or rats. Additionally, administration of maca improved the erectile function and decreased the latent period of erection of testes-removed rats.

Double-blind, placebo-controlled, randomized, parallel trials carried out on men have reported a widespread increase in sexual desire in the test group. One clinical study showed that the percentage of the men manifesting increased sexual desire was 40.0% and 42.2% after 8 and 12 weeks, respectively of maca treatment, which was significantly different from the results in the placebo-treated groups. But by contrast, maca did not affect penile blood flow in men with mild-to-moderate erectile dysfunction. Further larger scale studies on men are needed to assess the role(s) of maca.

The mechanisms of maca’s proposed improvement of sexual performance have been studied, but have not been fully clarified so far. Test results have shown that maca’s effect on fertility and sexual desire may not act by modulation of the hypothalamic–pituitary axis to regulate hormone secretion  and was also independent of changes in scores for depression and anxiety. Meanwhile, during oral administration of maca to mice, the apparent absence of correlation between effect on spontaneous motility and sexual behavior, seemed to support the hypothesis that maca had a pharmacological action independent of its nutritional value. Maca was also found not to activate the human androgen receptors and thus not to influence genes regulated by androgens.

Maca postmenopausal and osteoporosis benefits

The onset of the menopause symptoms is generally linked with reduced concentrations of the female sex hormones. One of the consequences of this is reduction of bone mineral density. Maca is said to regulate incretion, and has been used to treat women with menopausal symptoms. Studies in ovariectomized rats have shown that maca significantly increased calcium content in the femur of the rats. Phytosterols and other secondary metabolites in maca may contribute to this function.

Maca and growth rate improvement

Maca supplementation increased food intake, growth and feed utilization along with improving survival in rainbow trout juveniles. The improvement in survival might be explained via maca stimulating growth hormone and imparting increased resistance to diseases or stresses. First, it has been widely shown that maca contains many kinds of sterol, which have estrogenic effects and previous studies have shown that estrogen promoted the growth of yellow perch and production of growth hormone in goldfish. Secondly, maca improves immunity by increasing leucocyte number. Thirdly, anti-oxidant activity in maca meal may be partly responsible for the increased immunity and resistance to pathological antigens in the rainbow trout alevins and juveniles. Fourthly, maca is a good nurture which is abundant in protein, unsaturated fatty acid, vitamins and minerals.

Maca antiproliferative effects

Maca has anti-proliferative functions, and may mitigate the prostate weight increase induced by testosterone treatment.

Maca top 5 selling products

According to the amazon.com, following five Maca products are listed as top selling:

  • Mighty Maca Plus
  • Black Maca Liquid Extract
  • Earth Circle Organics Raw Organic Maca Powder
  • Whole World Botanicals – Organic Royal Maca
  • Sunfood Red Maca Powder
Maca top 5 selling products
Mighty Maca Plus

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About Miljan Krcobic 363 Articles
Miljan Krčobić. has bachelor degree in Pharmacy.