Dietary intake of iodine-enriched eggs decreases the incidence of mouse mammary tumors caused by the activated ErbB2 oncogene

Human epigenetic studies suggest that consumption of seaweed prevents mammary cancer, which possibly is explained by iodine daily intake. In this study, we evaluated the efficacy of dietary intake of iodine-enriched eggs on mammary tumor incidence caused by the expression of activated type ErbB2. Female transgenic mice were divided into three groups, and fed a basic diet, a diet supplemented with ordinary eggs, or with iodine-enriched eggs. The number of mammary tumors greater than 5mm in diameter was recorded in mice at 6months of age. We report that the average number of mammary tumors per mouse was significantly lower in the iodine-enriched egg-added diet group than in either the basic diet or ordinary egg diet groups. These results indicate that iodine intake through livestock-derived products can reduce the incidence of mammary cancers caused by the expression of activated type ErbB2.