In 2006, the version of the product sold in the U.S. was reformulated so it could be marketed as being "100% natural". This was achieved by eliminating the chelating agent calcium disodium EDTA, and replacing sodium citrate with potassium citrate to reduce the beverage's sodium content.[12] This reformulation contains no fruit juice and, in the U.S., is sweetened with high-fructose corn syrup (HFCS). The manufacturing process used in the production of HFCS has led some public health and advocacy groups to challenge the ad campaign's "natural" claims.[13] In 2007, after the Center for Science in the Public Interest threatened to sue 7 Up, it was announced that 7 Up would stop being marketed as "100% natural".