Toxic effects of brominated vegetable oils in rats

Groups of 15 weanling male and 15 female rats were fed semipurified diets containing 0, 0.1 or 0.5% brominated corn, cottonseed, olive or sesame oil for 105 days. Food consumption and body weight gain were normal. With the exception of male rats fed brominated olive oil, all rats fed 0.5% of the brominated oils had increased relative heart weights. Rats fed 0.5%, but not those fed 0.1%, brominated oil had degenerative myocardial lesions characterized by myocytolysis and fatty change. All rats fed the brominated oils had fatty changes in the liver, but the effect was more marked at 0.5% than at the 0.1% dietary level. Female animals fed the brominated oils had a slightly higher incidence of thyroid microfollicular hyperplasia than males.