Effects of galactose, glucose and fructose on carbohydrate-lipid metabolism.

Doses of glucose, galactose and fructose were administered orally and intravenously, while monitoring the levels of blood glucose, serum insulin, free fatty acids, cholesterol and triglycerides. Blood glucose increases when glucose is administered orally or intravenously, but does not vary significantly with any other sugar. The increase in insulinemia only with oral and intravenous glucose and with oral galactose is in agreement with the participation of intestinal factors in the determination of insulin secretion. The results obtained for free fatty acids with the various sugars may be due to the metabolic properties of each sugar. We found no significant variations in the levels of cholesterol and triglycerides, perhaps because of the short duration of the experiment.