Diet Coke
Diet Coke does not use a modified form of the Coca-Cola recipe, but instead an entirely different formula. The controversial New Coke, introduced in 1985, used a version of the Diet Coke recipe that contained high fructose corn syrup and had a slightly different balance of ingredients. In 2004, Coca-Cola introduced Coca-Cola C2, which it claims tastes much closer to Coca-Cola but contains half the carbohydrates. In 2005, the company introduced Coca-Cola Zero (replaced by "Coca-Cola Zero Sugar" in 2017), a sugar-free variation of regular Coca-Cola.
Diet Coke
The sodium benzoate was found to break down mitochondrial DNA in living yeast cells. Research published in 2007 for the British government's Food Standards Agency suggests that sodium benzoate (E211) is linked to hyperactive behavior and decreased intelligence in children. In January 2008 sodium benzoate was removed from production lines for Diet Coke sold in the UK, however it remains in other Coke products and other production locations.