Maca (also known as chichira or Peruvian ginseng) is a perennial, cruciferous, root vegetable native to the high altitude (from 3,500 to 4,500 meters above sea level) Puna region of the Andes mountains in south-central Peru. A member of the mustard family, which includes turnips and radishes, the plant has 12 to 20 scalloped leaves, growing up to 20 centimeters long, which lie close to the ground in a rosette pattern, with new leaves forming continuously at the center as the outer leaves die. Maca has off-white flowers typical of the mustard family, arising from a central stock. The seeds are ovoid, about 2 millimeters long. Maca has an edible, tuberous hypocotyl (the underground portion of the plant where the root joins the stem, often called the "root"), which resembles an underground pear in size and shape. The hypocotyl, which may be black, purple, yellow, or yellow with a purple band, has a creamy outer section rich in sugars and a firm inner section rich in starches.
Because it is one of the few leafy plants that can be successfully cultivated in the inhospitable climate and altitude of the Peruvian Puna, and it retains much of its nutritional value after years of storage, maca has long been a valuable food crop among native tribes of the region. Maca was used widely by the Incas in pre-Columbian times, and evidence of its cultivation has been found in archaeological sites dating back as far as 1600 B.C. The herb has long been reputed to increase fertility in both humans and animals. Shortly after the Spanish conquest, livestock that had been reproducing poorly in the higher elevations were fed maca, on the advice of Peruvian natives. This produced impressive results, according to Spanish chroniclers. The Spanish colonists eventually came to think so highly of the plant that they collected maca root as tribute for export to Spain.
Maca roots (hypocotyls) are rich in sugars, starches, protein, and essential minerals (particularly calcium), and contain significant amounts of vitamin C, riboflavin, and thiamin. They also contain unique alkaloid compounds, which are believed to be responsible for the herb's reputed biological activity.
Modern maca enthusiasts claim that the herb acts on the hypothalamus and pituitary to balance estrogen and testosterone levels, promoting reproductive function in both male and female, alleviating menopausal symptoms, and promoting general vitality. There is little scientific evidence to support these claims. Preliminary research suggests that maca may have an aphrodisiac effect in mice, but these effects have not been demonstrated in human subjects.
Dosage recommendations for maca vary with intended uses. Further research is needed to determine what dosage range (if any) may have therapeutic value. Maca has been consumed as a food for centuries and is not associated with any known toxicity or side effects; however, as with most plants, allergic reactions may occur in some individuals.