Lepidium meyenii

"Maca" redirects here. For other uses, see Maca (disambiguation).

Lepidium meyenii
Root
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Rosids
Order:	Brassicales
Family:	Brassicaceae
Genus:	Lepidium
Species:	L. meyenii
Binomial name
Lepidium meyenii Walp.
Synonyms
Lepidium peruvianum

Lepidium meyenii, known commonly as maca, is an herbaceous biennial plant or annual plant (some sources say a perennial plant) native to the high Andes of Peru and Bolivia. It is grown for its fleshy hypocotyl (actually a fused hypocotyl and taproot), which is used as a root vegetable and a medicinal herb. Its Spanish and Quechua names include maca-maca, maino, ayak chichira, and ayak willku.

Botanical characteristics

Although this species has been used by the Andean people for two thousand years, their knowledge was first brought under Linnaeus' system of classification by Gerhard Walpers in 1843 as Lepidium meyenii. In studying different specimens since the late 1960s, most botanists now consider the widely cultivated natural maca of today to be a newer domesticated species, L. peruvianum. This more recent designation was made by Dr. Gloria Chacon. The Latin name recognized by the USDA continues to be Lepidium meyenii, however most contemporary botanists employ the name "peruvianum" and consider it most accurate to describe the species". The growth habit, size, and proportions of maca are roughly similar to those of the radish and the turnip, to which it is related. The green, fragrant tops are short and lie along the ground. The thin frilly leaves are born in a rosette at the soil surface, and are continuously renewed from the center as the outer leaves die. The off-white, self-fertile flowers are borne on a central raceme, and are followed by 4–5 mm siliculate fruits, each containing two small (2-2.5 mm) reddish-gray ovoid seeds. The seeds, which are the plant's only means of reproduction, germinate within five days given good conditions. The seeds have no dormancy, as maca's native habitat remains harsh year-round.

Maca is the only member of its genus with a fleshy hypocotyl, which is fused with the taproot to form a rough inverted-pear-shaped body. Maca does vary greatly in the size and shape of the root, which can be triangular, flattened circular, spherical or rectangular, the latter of which forms the largest roots. Maca hypocotyls can be gold or cream, red, purple, blue, black or green. Each is considered a genetically unique variety, as seeds of the parent plants grow to have roots of the same color. Recently, specific phenotypes (in maca, 'phenotype' pertains mainly to root color) have been exclusively propagated to ascertain their different nutritional and therapeutic properties. Cream colored roots are the most widely grown and are favored in Peru for their enhanced sweetness and size. Black maca is considered the strongest in energy and stamina-promoting properties, being both sweet and slightly bitter in taste. Red maca is becoming popular with many people, and has been clinically shown to reduce prostate size in rats. These three phenotypes are the primary ones being grown and exported.

Maca is traditionally grown at altitudes of approximately 8,000-14,500 ft (2,400-4,400 metres) elevation. It grows well only in cold climates with relatively poor agricultural soils, habitats where few other crops can be grown. Like many cruciferous root vegetables, maca can exhaust soils that are not well tended. Nearly all maca cultivation in Peru is carried out organically, as there are few pests naturally occurring at such high altitudes, and maca itself is seldom attacked. Maca is sometimes interplanted with potatoes, as it is known to maca farmers that the plant itself naturally repels most root crop pests. Maca croplands are fertilized mainly with sheep and alpaca manure, and are often rested for a period of years to rebuild nutrients in the soils. 8 to 10 months elapse between sowing and maturity for harvest. The yield for a cultivated hectare is approximately 5 tons.^{[citation needed]} Maca is typically dried for further processing, which yields about 1.5 tons total. Although maca has been cultivated outside the Andes, it is not yet clear whether it develops the same active constituents or potency. Hypocotyls grown from Peruvian seeds form with difficulty at low elevations, in greenhouses or in warm climates.

For approximately 2,000 years, maca has been an important traditional food and medicinal plant in its limited growing region, where it is well-known and celebrated. It is regarded as a highly nutritious, energy-imbuing food, and as a medicine that enhances strength, endurance and also acts as an aphrodisiac. During Spanish colonization maca was used as currency.

Constituents

In addition to sugars and proteins, maca contains uridine, malic acid and its benzoyl derivative, and the glucosinolates, glucotropaeolin and m-methoxyglucotropaeolin. The methanol extract of maca tuber also contained (1R, 3S)-1-methyltetrahydro-carboline-3-carboxylic acid, a molecule which is reported to exert many activities on the central nervous system. Many different alkamides were found in maca.

(1R, 3S)-1-methyltetrahydro-carboline-3-carboxylic acid

The nutritional value of dried maca root is high, similar to cereal grains such as rice and wheat. The average composition is 60-75% carbohydrates, 10-14% protein, 8.5% dietary fiber, and 2.2% fats. Maca is rich in the dietary minerals calcium and potassium (with low content of sodium), and contains the essential trace elements iron, iodine, copper, manganese, and zinc as well as fatty acids including linolenic acid, palmitic acid, and oleic acids, and 19 amino acids.

Further, Maca contains selenium and magnesium^{[citation needed]}, and includes polysaccharides. Maca's reported beneficial effects for sexual function could be due to its high concentration of proteins and vital nutrients; maca contains a chemical called p-methoxybenzyl isothiocyanate, which reputedly has aphrodisiac properties.

Uses and preparation

Maca has been harvested and used by humans in the Andean Mountains for centuries. Contrary to frequent claims that maca's cultivation was common in what is today Peru, it has been shown that until the late 1980s, maca has only been cultivated in a limited area around Lake Junin, in Central Peru. Historically, maca was often traded for lowland tropical food staples, such as corn, rice, manioc (tapioca roots), quinoa and papaya. It was also used as a form of payment of Spanish imperial taxes. It is often cited that maca was eaten by Inca imperial warriors before battles.^{[citation needed]} Their legendary strength was allegedly imparted by the preparatory consumption of copious amounts of maca, fueling formidable warriors. After a city was conquered, the women had to be protected from the Inca warriors, as they became ambitiously virile from eating such quantities of maca. This is of course an appealing endorsement for the masculine angle of maca's recent marketing campaign. Whether or not this oft repeated historical use is actually true has yet to be determined. Those who have studied maca's history have not been able to locate formal mention of this particular use.^{[citation needed]}

In Peru, maca is prepared and consumed in several ways, although traditionally it is always cooked. The freshly harvested hypocotyl can be roasted in a pit (called huatia), and this is considered a delicacy. Fresh roots are usually available only in the vicinity of the growers. The root can also be mashed and boiled to produce a sweet, thick liquid, dried and mixed with milk to form a porridge or with other vegetables or grains to produce a flour that can be used in baking. If fermented, a weak beer called chicha de maca can be produced. In 2010 a US based brewery called Andean Brewing Company, became the first company to produce and commercialize beer made from Maca under the brand KUKA Beer. The leaves can also be prepared raw in salads or cooked much like Lepidium sativum and Lepidium campestre, to which it is genetically closely related.

The growing demand of the supplement industry has been one of the primary reasons for maca's expanding cultivation in Peru and Bolivia. The prominent product for export is maca flour, which is a baking flour ground from the hard, dried roots, "harina de maca." Maca flour (powder) is a relatively inexpensive bulk commodity, much like wheat flour or potato flour. In Peru, maca flour is used in baking as a flour base and a flavoring. There are many companies who sell raw maca flour as a bulk supplement, however maca is not eaten raw in its native territory, and can cause gastric problems unless it is cooked. The supplement industry uses both the dry roots and maca flour for different types of processing and concentrated extracts. An internet query will show dozens of different extracts available, each touting a particular efficaciousness for a traditional use or health claim. Another common form is maca which has undergone gelatinization. This is an extrusion process which separates and removes the tough fiber from the roots using gentle heat and pressure, it is sometimes used on other vegetables with a tough fiber matrix. Raw maca is difficult to digest due to it's thick fibers and goitrogen content. Gelatinization was developed for maca specifically to mimic the activity of cooking, and to allow gentler digestion. Gelatinized maca is employed mainly for therapeutic and supplement purposes, but can also be used like maca flour as a flavor in cooking. Available also is a freeze-dried maca juice, which is a juice squeezed from the macerated fresh root, and subsequently freeze-dried high in the Andes.

Health effects

Maca is consumed as food for humans and livestock, suggesting any risk from consumption is rather minimal. It is considered safe to eat as any other vegetable food. However, maca does contain glucosinolates, which can cause goiters when high consumption is combined with a diet low in iodine. This being said, darker colored maca roots (red, purple, black) contain significant amounts of natural iodine, a 10-gram serving of dried maca generally containing 52 µg of iodine. Though this is common in other foods with high levels of glucosinolate, it is uncertain if maca consumption can cause or worsen a goiter. Maca has been shown to reduce enlarged prostate glands in rats.

Small-scale clinical trials performed in men have shown that maca extracts can heighten libido and improve semen quality. A small double-blind, randomized, parallel group dose-finding pilot study has shown that Maca root may alleviate SSRI-induced sexual dysfunction. Maca does not affect sex hormone levels in humans, and has not been shown to act on hormones directly. It has been presumed that maca's effects may be due to the root's unique nutritional profile, which provides optimum levels of nutrients utilized by the body's endocrine system. In addition, maca has been shown to increase mating behavior in male mice and rats. A recent review states "Randomized clinical trials have shown that maca has favorable effects on energy and mood, may decrease anxiety and improve sexual desire. Maca has also been shown to improve sperm production, sperm motility, and semen volume."

External links

• What is Maca Used for Today? at NYU Medical Center
• The Truth About Maca