 Vitamin C may prevent some cancers by inhibiting the formation of mutagenic N-nitroso compounds (nitrosamine).Flavonoids, such as EGCG in green tea, have also been shown to be effective antioxidants and may have anti-cancer properties.Epidemiological studies indicate that a diet rich in fruits and vegetables is associated with lower incidence of some cancers and longer life expectancy, however, the effectiveness of antioxidant supplements in cancer prevention in general is still the subject of some debate.