Effect of D-Fructose on Lipid Metabolism

Feeding of D-fructose or sucrose produces hyperlipemia (increase in serum triglyceride levels) in man159,274-283 and laboratory animals.284-292 Induced hyperlipemia may cause atherosclerosis.293 Thus, it is important to understand the mechanism by which D-fructose induces increased levels of serum triglyceride. 

Comparison277 of Enzyme Activities for Those Primarily Effective in Liver Metabolism 

Enzyme Enzymic activity Enzyme Enzymic activity  

D-Fructose 1-phosphate aldolase 50.4 8.8 (4) D-Fructose 1,6-diphosphate aldolase 54.7 7.0 (4) 

A diet high in D-fructose produces increased concentrations of pyruvate, malate, and acetyl coenzyme A (AcSCoA).294 295 D-Fructose enhances formation of AcSCoA from pyruvate by stimulating pyruvate oxidation.296 As D-fructose causes a fall in the hepatic ATP concentration, pyruvate dehydrogenase (EC 1.2.4.1) is activated, and it produces an increase in AcSCoA formation from pyruvate.297 Thus, dietary sucrose and D-fructose produce higher hepatic fatty acid synthesis than does dietary D-glucose, because of their stimulation of AcSCoA formation. 

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