| Diets rich in polyphenols and dietary fiber are associated with reduced risk of cardiovascular disease, stroke, hypertension and some cancers. High polyphenol diets have also been reported to inhibit the growth of young animals and cause liver necrosis. Grape pomace (GP), the residue of grapes after wine making, is rich in dietary polyphenols and fiber, and has potential as a functional food ingredient to improve health, but its safety needs to be further investigated. The objective of this study was to determine the effect of diets containing different amount of GP on the growth performance and blood chemistry using a young rat model. To complete this objective twenty Sprague Dawley rats of 7-week old were randomly divided into 4 groups that were fed AIN-93G diets modified by substituting 0, 10, 20 and 30% of carbohydrate with GP for 10 weeks (The diets thus obtained contained,0, 6.9%, 13.8% and 20.7% of GP). The original AIN-93G (0% GP) was used as control diet. Feed consumption, body weight, length and height were recorded weekly. Blood samples were taken biweekly to analyze plasma lipid profile, blood cell counts, and biomarkers important for liver, pancreas and kidney functions. At the end of feeding period, the rats were fasted overnight and euthanized by exsanguination under anesthesia. Livers, hearts and kidneys were collected and their weights were recorded. Results show that the diet containing up to 20.7% of GP did not influence the body weights, lengths and heights of rats. As GP content increased, the blood triglyceride and VLDL decreased, HDL and LDL increased slightly, total cholesterol remained constant. Alanine aminotransferase activity increased slightly with increasing GP level and feeding time, but amylase activity was not influenced. The blood glucose, creatinine, protein levels, and the blood cell counts were not affected by GP content. In conclusion, GP in AIN-93G diet did not influence the growth performance of young rats, total blood counts and the functions of liver, kidney and pancreas, but it exhibited both positive and negative effects on the blood lipid profile. More animal studies with high cholesterol diet are needed to test the hypolipidemic effect of GP. |
