Maca

Lepidium meyenii or maca is an herbaceous biennial plant or annual plant (some sources say a perennial plant) native to the high Andes of Bolivia and Peru. 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



The plant is considered a member of the species Lepidium meyenii, first observed and designated by Gerhard Walpers in 1843. In studying different specimens since the late 1960s, most botanists now consider the widely cultivated maca of today to be a newer domesticated species, L. peruvianum.[1] This more recent designation was made by Dr. Gloria Chacon. The Latin name recognized by the USDA continues to be Lepidium meyenii,[2] however most contemporary botanists employ the name "peruvianum" and consider it most accurate to describe the species".[3] 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/cream, red, purple, black and green. Each is considered a genetically unique variety, as seeds of the parent plants grow to have roots of the same color. Recently, specific color strains 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-promoting properties, being both sweet and slightly bitter in taste [4]. Red maca is also becoming popular with many people, and has been clinically shown to reduce prostate size in rats.[5] These three ecotypes are the most commonly grown and exported.






Maca is traditionally grown at altitudes of approximately 4,100–4,500 metres (13,000–15,000 ft) 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. 8–10 months elapse between sowing and maturity for harvest. The yield for a cultivated hectare is approximately 5 tons. 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. Seeds obtained from Bolivian maca, which is native to lower altitudes, are more easily grown under such conditions [6].






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.[7] It is regarded as a highly nutritious, energy-imbuing food, and as a medicine that enhances strength, endurance and also acts as an aphrodisiac.[7] During Spanish colonization maca was used as currency.[8][9]






[edit] 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.[10] The nutritional value of dried maca root is high, similar to cereal grains such as rice and wheat. It contains 60% carbohydrates, 10% protein, 8.5% dietary fiber, and 2.2% fats. Maca is rich in essential minerals, especially selenium, calcium, magnesium, and iron, and includes fatty acids including linolenic acid, palmitic acid, and oleic acids, and 19 amino acids, as well as polysaccharides.[11] Maca's reported beneficial effects for sexual function could be due to its high concentration of proteins and vital nutrients,[9] though maca contains a chemical called p-methoxybenzyl isothiocyanate, which reputedly has aphrodisiac properties.[1]






[edit] 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 and Bolivia, it has been shown that until the late 1980s, maca has only been cultivated in a limited area around Lake Junin, in Central Peru.[12] Historically, maca was often traded for lowland tropical food staples, such as corn, rice, maniot (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.[13] 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.[14]






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. 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.[15]






The growing demand of the supplement industry has been one of the primary reasons for maca's expansion. The prominent product is maca flour, which is ground from the hard, dried roots. In Peru, maca flour is used in baking as a base and a flavoring. The supplement industry uses both the dry roots and maca flour for different types of processing and concentrated extracts. A quick internet query will show dozens of different extracts available, each touting some enhanced efficaciousness for a traditional use or health claim. Another common form is maca which has undergone gelatinization. This is an extrusion process, sometimes used for other vegetables, which removes the fiber from the roots using slight heat and pressure. Maca is one of many root vegetables with a dense fiber matrix which can be gelatinized to create products with more efficient digestion. Gelatinized maca is many fold stronger than powdered root, and is employed for mainly for therapeutic, medicinal and supplement purposes. It can also be used like maca flour. There is also freeze-dried maca juice, which is a juice squeezed from the macerated fresh root, and subsequently freeze-dried. [16]






[edit] 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 goitres when high consumption is combined with a diet low in iodine. 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.[1] Though this is common in other foods with high levels of glucosinolate, it is uncertain if maca consumption can cause or worsen a goiter.[17] Maca has been shown to reduce enlarged prostate glands in rats[18][19] though its effects on humans are unknown.






Small-scale clinical trials performed in men have shown that maca extracts can heighten libido and improve semen quality,[20][21] though no studies have been performed on men with sexual dysfunction or infertility. 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 hormone-normalizing effects may be due to the root's unique nutritional profile, which provides optimum levels of nutrients utilized by the body's endocrine system.[22] In addition, maca has been shown to increase mating behavior in male mice and rats.[23]






[edit] Legality


Maca is considered a medicinal herb in Norway, and is not legal without a prescription.[24]