Effects of fructose and sucrose intake on lipid metabolism in 9‐month‐old rats feeding on different levels

This study was designed to evaluate effects of fructose(F) and sucrose(S) intake on lipid metabolism in 9‐month‐old rats. A total of 100 Spraque‐Dawley male rats were raised 10 rats in each group, for one month, in 10 different groups. One group was raised of the control diet that contain cornstarch of source of carbohydrate(100% of CHO). Three groups were raised of varying levels of S of 25%, 50% and 100% of CHO, labeled here as 25S, 50S and 100S, respectively. Three groups were raised of varying levels of F of 25%, 50% and 100% of CHO, labeled here as 25F, 50F and 100F, respectively. The last three groups were raised of varying levels of F of 14%, 28% and 57% of carbohydrate, labeled here as 14F, 28F and 57F, respectively. Note that the last three groups have a similar level of sweetness by 25S, 50S and 100S, respectively. Total lipid, triglyceride(TG) and total cholesterol in plasma and liver, HDL‐cholesterol concentration and free fatty acid(FFA) contents in plasma were measured. Plasma malic enzyme(ME) and glucose‐6‐phosphate dehydrogenase(G‐6‐PDH) activity were also determined. Total lipid, TG concentrations in plasma were not significantly different among all the groups. Total and HDL‐cholesterol concentrations of 25F, 50F, 100F tended to be higher than those of the other groups. Plasma FFA content of S intake groups was higher than that of F intake groups. Liver ME and G‐6‐PDH activities of all non‐control diet groups were significantly higher than those of the control group. Both S and F intakes about equally increased the levels of enzyme activities. In conclusion, S and F intakes had little effect on lipid metabolism. This research was supported by grants from Daesang Co. Ltd.