Maca is a plant from the Andes area of South America. It has several different forms, such as black maca, yellow maca and red maca. Although it is edible as a vegetable, the plant also has uses in traditional medicine. Scientific studies on rodents indicate that black maca may benefit sperm production and have antidepressant effects, although studies in humans are not conclusive.
Technically known as Lepidium meyenii, maca grows only in the Andes mountains. It is restricted to a range between about 13,100 and 14,700 feet (4,000 to 4,500 m). Farmers in the area can grow it as a vegetable, as it has a root that is high in carbohydrates. Maca is closely related to turnips and radishes, as they are all part of the mustard family of plants.
Medicinal uses of the plant include treatments to improve fertility, and investigations into the potential benefits of the plant in both male and female fertility are ongoing, as of 2011. Studies on mice and rats do indicate that the root improves levels of sperm production in male rodents, and may help female rodents have more offspring. Human studies also raise the possibility that the plant helps sperm production in men, and also increases male libido.
Other traditional uses of the plant include relieving tiredness, improving anemia and as a treatment for tuberculosis infections. Due to the proven fertility and libido effects of the plant, the maca is also known as the Peruvian ginseng, after the Asian plant with similar purported effects. While yellow maca is the most common form of the maca plant, it is black maca which is most associated with possible reproductive benefits.
The part of black maca that usually is eaten or otherwise taken as herbal medicine is the root, or the hypocotyl. This is a thick, tuber-like structure which sits above ground below the leaves, much like the long middle portion of a beansprout. Varieties of maca tend to get their names from the color of the hypocotyl of the plant. Cooked or raw maca are options for the consumer, but the hypocotyl or root can also be processed into other forms. These include a flour of ground maca, a toasted powder for coffee, or a powder for use in capsule or tablet form.
As the plant has not been formally studied in detail, all of the potential side effects of black maca are unknown as of 2011. Goiter, which involves the swelling of the thyroid gland, is one possibility if the person who takes it also ingests too little iodine. Another possibility is that the plant may have adverse effects on the cardiovascular system.