Decreased food efficiency ratio, growth retardation and changes in liver fatty acid composition in rats consuming thermally oxidized and polymerized sunflower oil used for frying.
Changes in food intake, body weight, liver weight, hepatosomatic index and hepatic fatty acid composition were studied in growing male Wistar rats fed a diet containing sunflower oil that had been used repeatedly for frying. During a period of 27 days, the animals were fed semi-synthetic diets containing either 15% used oil with 19.1% polar material (group 2) or 15% unused oils with 5.1% polar material (group 1). Although food intake was similar in both experimental groups, final body weight, body weight gain, food efficiency ratio and protein efficiency ratio were significantly lower in group 2. The increase of the hepatosomatic index in rats of group 2 seems related to a higher ingestion of potential toxic components (dimers and polymers of triglycerides and oxidized triglycerides) by this group. The livers of nine out of the 10 animals studied also showed moderate fibrotic degenerative areas with severe vacuolization, together with regenerative areas containing eosinophilic binuclear hepatocytes. In addition, livers of group 2 animals showed a 12% higher content of arachidonic acid. Data suggest that higher arachidonic acid levels would be needed for regeneration to palliate liver injury. These data suggest that frying sunflower oil is potentially toxic; assessment of risk is therefore necessary for frying fats with a high polar content.
López-Varela
S
S
Departamento de Nutrición y Bromatologia I. (Nutrición), Facultad de Farmacia, Universidad Complutense, Madrid, Spain.
Sánchez-Muniz
F J
FJ
Cuesta
C
C
D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage / Q000378:metabolism*; D004044:Dietary Proteins / Q000378:metabolism; D004195:Disease Models, Animal; D004435:Eating / Q000187:drug effects*; D005227:Fatty Acids / Q000378:metabolism; D005511:Food Handling; D006368:Helianthus; D006358:Hot Temperature; D008099:Liver / Q000187:drug effects* / Q000473:pathology; D008106:Liver Cirrhosis, Experimental / Q000139:chemically induced; D008297:Male; D008856:Microscopy, Fluorescence; D009929:Organ Size / Q000187:drug effects / Q000502:physiology; D010084:Oxidation-Reduction; D010938:Plant Oils / Q000008:administration & dosage / Q000378:metabolism / Q000633:toxicity*; D011108:Polymers; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D000074242:Sunflower Oil; D015430:Weight Gain / Q000187:drug effects* / Q000502:physiology
D004042:Dietary Fats, Unsaturated; D004044:Dietary Proteins; D005227:Fatty Acids; D010938:Plant Oils; D011108:Polymers; D000074242:Sunflower Oil