Dietary fish oil supplementation has no beneficial effects on prevention of diabetes in the spontaneously diabetic (BB/W) rat

The effect of dietary fish oils on the incidence of diabetes was studied in the spontaneously diabetic BB/W rat. Two groups of age, sex and litter matched BB/W rats received isocaloric diets that were either fish oil supplemented (16.7% EPA and 12% DHA), or corn oil supplemented (65% linoleic acid) from 25-35 days of age until termination of the study. There were no differences in the incidence of diabetes between the two groups of rats. Sixty-eight percent of the rats fed the fish oil diet became diabetic, and 63% of the corn oil fed rats became diabetic. Thus, our data failed to show any protective effect of omega-3 polyunsaturated fatty acids on the development of diabetes in these animals. Considering these experimental results, rats may not be an appropriate model for studying effects of omega-3 polyunsaturated fatty acids in an eicosapentaenoic system related disorder. In studying fish oils and their potential effects in humans, we must be careful in interpreting the results from animal models.