High altitude, high demand, high cost

Maca, a member of the Brassicaceae family, has been cultivated in Peru for more than 2,000 years, where it grows exclusively in the central Andes at an altitude of about 3,000 meters, according to Yang Shengchao, a professor at Yunnan Agriculture University.

Yang said maca's medicinal properties have seen it used as a traditional food supplement for centuries.

The root, which was introduced to China in 2000, is believed to contain significant amounts of amino acids, carbohydrates, vitamins and minerals, natural medicinal and nutritional qualities beneficial to human health, he said.