How do nutritional fats and carbohydrates affect the action of insulin?

Silvia Wein, Elena Seböková, Daniela Gasperiková, Berit Adolphi, Iwar Klimes, Maria Pfeuffer, Jürgen Schrezenmeir und Siegfried Wolffram, Kiel/Bratislava/Karlsruhe/Bad Schwartau

Major factors known to promote insulin resistance include obesity and the dietary intake of long chain saturated fatty acids , while medium chain FA and polyunsaturated FA counteract the development of insulin resistance. Three different feeding experiments were performed in rats in order to study the effects of various sources of energy on insulin sensitivity (IS).

In experiment 1 (4 weeks), high fat diets supplemented with polyunsaturated FA (n3 and n6) were compared. In experiments 2 (4 weeks) and 3 (16 weeks), high fat diets with saturated long chain (LCTsat) and medium chain (MCTsat) FA were compared with an isocaloric high carbohydrate diet. While diets containing LCTsat or n6 FA reduced IS compared to a low fat control diet, the n3 FA and MCTsat enriched high fat diets prevented the development of insulin resistance. Nevertheless, after 16 weeks on the diets, IS was higher in the MCTsat and HCH groups than in the LCTsat, but was significantly lower than the 4 weeks data in all groups. A positive energy balance, irrespective of the energy source, seems to cause fat accumulation in liver tissue and thereby a reduction in insulin sensitivity.

Keywords: insulin, insulin sensitivity, fatty acids, n3 fatty acids, medium chain triglycerides, carbohydrates

Sie finden den Artikel in deutscher Sprache in Ernährungs Umschau 08/10 ab Seite 416.