Commercial ginseng is sold in over 35 countries, with China as the largest consumer. In 2013, global sales of ginseng exceeded $2 billion, of which half was produced by South Korea. In the early 21st century, 99% of the world's 80,000 tons of ginseng was produced in just four countries: China (44,749 tons), South Korea (27,480 tons), Canada (6,486 tons), and the United States (1,054 tons). All ginseng produced in South Korea is Korean ginseng ("P. ginseng"), while ginseng produced in China includes "P. ginseng" and South China ginseng ("P. notoginseng"). Ginseng produced in Canada and the United States is mostly American ginseng ("P. quinquefolius"). Ginseng may be included in energy drinks or herbal teas in small amounts or sold as a dietary supplement. The root is most often available in dried form, either whole or sliced. Ginseng leaf, although not as highly prized, is sometimes also used. In Korean cuisine, ginseng is used in various "banchan" (side dishes) and "guk" (soups), as well as tea and alcoholic beverages. Ginseng-infused tea and liquor, known as "insamcha" (literally "ginseng tea") and "insamju" ("ginseng liquor") is consumed. Although ginseng is commonly sold as a dietary supplement, concerns have been raised about manufactured ginseng products containing toxic metals or filler materials, such as rice or wheat. In 2012, Chinese health regulators reclassified ginseng root as a dietary herb that can be used in health foods without prior approval, as long as no specific health claims are made for it; previously, it had been classified as an herbal drug whose inclusion in health foods required prior approval and licensing. Ginseng-infused teas and energy drinks are consumed today in China and neighboring countries as a kind of tonic for vitality, especially by men 50 and older, who might use them on a daily basis. Sliced bits of the dried root are also used in soups and other hot dishes. Although ginseng has been used in traditional medicine for centuries, modern research is inconclusive about its biological effects. Preliminary clinical research indicates possible effects on memory, fatigue, menopause symptoms, and insulin response in people with mild diabetes.