Sodium butyrate inhibits the enhancing effect of high fat diet on mammary tumorigenesis.

We have studied the effect of butyrate on mammary tumorigenesis by 7,12-dimethylbenz(a)anthracene. As reported previously, a high incidence of mammary tumors was observed in rats fed a basal diet containing 20% margarine. However, the enhancing effect of margarine was inhibited when sodium butyrate was supplemented in the high margarine diet. Sodium butyrate did not cause any effect when it was supplemented in the basal diet. The result suggests a possibility that a part of the inhibitory effect of butter on mammary tumorigenesis, which we had previously reported, was caused by butyrate milk lipids.