Effect of deep frying oil given with and without dietary cholesterol on lipid metabolism in rats

The purpose of the present study was to investigate the effect of dietary deep frying oil (DO) on levels of plasma and liver lipids, and fecal steroid excretion in rats. The DO was prepared by frying fresh soybean oil (FO) at 200°C, 6 h each, for four consecutive days. Male weanling Sprague-Dawley rats ingested diets containing 15% FO or DO with or without 1% cholesterol for 6 weeks. Rats on the DO diet with cholesterol had a lower food intake and body weight gain compared to the FO diet with cholesterol. The concentration of plasma esterified cholesterol was higher in rats on DO diet than in rats on FO diet, although the plasma triacylglycerols (TG) were similar between the groups. The DO diet resulted in a lower content of liver TG and cholesterol, and less excretion of acidic and neutral steroids than did the FO diet. These results showed that ingestion of frying oil with cholesterol aggravated hypercholesterolemia, even though absorption of dietary cholesterol may be lower in rats on DO diet. © 1995.