Quality of dietary fatty acids, insulin sensitivity and type 2 diabetes

Epidemiological evidence and intervention studies clearly indicate that the quality of dietary fat influences insulin sensitivity in humans, in particular, saturated fat worsens it, while monounsaturated and x-6 polyunsaturated fats improve it. Long chain x-3 fatty acids do not seem to have any effect on insulin sensitivity, at least in humans. Moreover, there is also good epidemiological evidence that the quality of dietary fat may influence the risk of type 2 diabetes, again with saturated fat increasing and unsaturated fat decreasing this risk. No intervention study is available at the moment on this specific point, even if in the Finnish Diabetes Prevention Study the incidence of type 2 diabetes was reduced by a multifactorial intervention, which also included a reduction of saturated fat intake.