Effect of dietary fructose on fatty acid synthesis in adipose tissue and on triglyceride concentration in blood in the rat.

Abstract

Experiments where the inhibition of lipid synthesis from glucose in adipose tissue of rats fed sucrose was analyzed led to the following conclusions:The nutritional factor leading to inhibited fatty acid synthesis from glucose in adipose tissue is fructose, ingested either as such or as part of sucrose. A high fructose intake inhibits in addition to glucose incorporation also acetate incorporation into fatty acids. This indicates that fructose-induced inhibition of fatty acid synthesis in adipose tissue takes place in some step(s) between acetate and fatty acids. Inhibition of fatty acid synthesis in adipose tissue is not caused by the direct effect of the fructose molecule on adipose tissue, but is probably the result of hypertriglyceridemia and the ensuing enhanced supply of fatty acids from triglycerides of blood lipoproteins. The chronological course of changes of hypertriglyceridemia and fatty acid synthesis in adipose tissue, as well as experiments where the effect of diets with a rising fructose ratio was investigated, provide indirect evidence that the factor which determines quantitatively the inhibitory effect of fructose ingestion is probably rather the actual uptake of preformed fatty acids in adipose tissue than the magnitude of hypertriglyceridemia per se.