Long-term toxicity and carcinogenicity studies of the bread improver potassium bromate 2. Studies in mice

Abstract

Mice were fed for 80wk on five bread-based diets in which the bread was prepared from untreated flour or from flour treated with 50 or 75 ppm potassium bromate or with one of two mixtures of potassium bromate with other commonly-used additives. Appearance, behaviour, health and survival were similar in test and control groups. No carcinogenic effects were produced by any of the diets. Anaemia was present in all male groups (including controls), except the group receiving 50 ppm bromate together with three other flour additives, and in females terminally. There was a dose-related decrease in the red blood cell count of males at 3 months and neutrophilia seen at 12 and 18 months was dose-related. Raised blood-sugar levels. related to dose were found in females at 3 and 12 months. but the effect was not significant at 18 months, and was not found at any stage in the males. Dose-related differences in the weights of the heart, the pituitary and the uterus were found; when expressed relative to body weight, values for the heart and the uterus were no longer dose-related, but the pituitary, the brain, the kidneys and the thyroid showed significant dose-related trends. These effects were not associated with pathological changes in the structures of the tissues concerned.