Turmeric is a common spice that comes from the root of Curcuma longa. It contains a chemical called curcumin, which might reduce swelling. Turmeric has a warm, bitter taste and is frequently used to flavor or color curry powders, mustards, butters, and cheeses. Because curcumin and other chemicals in turmeric might decrease swelling, it is often used to treat conditions that involve pain and inflammation. People commonly use turmeric for osteoarthritis. It is also used for hay fever, depression, high cholesterol, a type of liver disease, and itching, but there is no good scientific evidence to support most of these uses.