Vitamin C Supplementation Restores the Impaired Vitamin E Status of Guinea Pigs Fed Oxidized Frying Oil ,

Abstract

To investigate the effect of dietary oxidized frying oil (OFO) on tissue retention of vitamin C, and to explore the effect of vitamin C supplementation on tissue vitamin E concentrations and lipid peroxidation, male weanling guinea pigs were divided into four groups. Guinea pigs were fed 15% OFO diets supplemented with vitamin C at 300, 600 or 1500 mg/kg diet. Control animals were fed a diet containing 15% fresh untreated soybean oil with 300 mg/kg of vitamin C. After 60 d of feeding, body weight gain, food intake, feed efficiency and plasma triglyceride concentration were significantly lower in guinea pigs fed OFO diets than in controls (P< 0.05). However, plasma cholesterol concentration was highest in guinea pigs fed the OFO diet supplemented with 300 mg/kg vitamin C. Increasing vitamin C in OFO diets significantly reduced plasma cholesterol concentration. Plasma and tissue vitamins C and E concentrations were significantly lower in the OFO-fed guinea pigs receiving 300 mg/kg vitamin C than in controls. Greater levels of supplemental vitamin C increased tissue vitamins C and E. Guinea pigs fed OFO diets had significantly higher tissue levels of thiobarbituric acid reactive substances (TBARS) (P< 0.05) than controls. Our results demonstrated that OFO feeding, which impaired α-tocopherol retention and increased TBARS, could be alleviated somewhat by vitamin C supplementation. J. Nutr. 128: 116–122, 1998.