Effect of dietary intake of fish oil and fish protein on the development of L-azaserine-induced preneoplastic lesions in the rat pancreas.

The effect of dietary intake of fish (menhaden) oil and fish (cod) protein on the development of pancreatic preneoplastic lesions was examined in male Wistar rats. Fourteen-day-old animals were given a single ip injection of 30 mg L-azaserine/kg body weight [CAS: 115-02-6; diazoacetate serine (ester)]. At 21 days of age they were weaned and maintained on dietary treatment for 4 months. Fish protein did not appear to produce a significantly different preneoplastic response when compared to casein as a protein source. However, a 20% menhaden oil diet, rich in omega 3 fatty acids, produced a significant decrease in the development of both the size and number of preneoplastic lesions when compared to a 20% corn oil diet rich in omega 6 fatty acids. This study provides evidence that fish oils, rich in omega 3 fatty acids, may have potential as inhibitory agents in cancer development.