While a number of studies have suggested a cancer preventative activity of Vitamin E, several recent large-scale human trials with alpha-tocopherol, the most commonly recognized and used form of vitamin E, have failed to show such an effect. Chung S. Yang, from, Rutgers University (New Jersey, USA), and colleagues completed animal studies for colon, lung, breast and prostate cancer, finding gamma and delta-tocopherols – the forms of Vitamin E found in soybean, canola and corn oils as well as nuts, prevented cancer formation and growth. Reporting that: “When animals are exposed to cancer-causing substances, the group that was fed these tocopherols in their diet had fewer and smaller tumors,” the study authors observed that: “When cancer cells were injected into mice these tocopherols also slowed down the development of tumors,” lending them to conclude that: “we suggest that vitamin E, as ingested in the diet or in supplements that are rich in [gamma and delta-tocopherols], is cancer preventive.”