Effect of diet on spontaneous disease in the inbred mouse strain C57B1/10J

The incidence of spontaneous disease in an inbred mouse strain, C57B1/10J, is compared in control groups from 5 carcinogenicity studies performed in the same laboratory between 1973 and 1980; the mice were bred at 2 laboratories, and 3 different diets were used. Significant differences were found in the incidence of total tumours and in many individual tumour types. The incidence of major non-neoplastic diseases also varied markedly. The effects of diet on spontaneous disease are now well-established. The results support this contention and demonstrate that diet may override the genetic characteristics of an inbred strain.