First Nutella, then toast, now toothpaste - is there nothing left in the world that won't cause the Big C? Now scientists say that an ingredient widely used in toothpaste can lead to precancerous growths. The additive in question is called titanium dioxide -  often referred to as E171 Researchers in France and Luxembourg carried out tests on rats and found that 40 per cent of the rats that were given the additive in their drinking water developed precancerous growths (which are not malignant but can develop into more serious cancers) Reports in the Independent say that the product is widely used in sweets, chocolate, biscuits and chewing gum. It is also used in toothpaste to whiten products. Research from the International Cancer research agency already found that inhaling titanium dioxide (like from paint) could cause cancer  - but this new study is the first time the link has been made with oral consumption. As yet, it is unclear if the product might have a similar effect in humans  - but in France, the Government has ordered an immediate inquiry into the safety of E171 The results will be published by the end of march.