Apple favourably affects parameters of cholesterol metabolism and of anti-oxidative protection in cholesterol-fed rats

The effects of apples on lipid metabolism were studied on 40 male Wistar ra ts adapted to semi-purified diets containing 0.3% cholesterol. In the exper imental 'apple' diet, a part of starch (15%) was replaced by lyophilized ap ple (Gala variety). In the control diet, 13% of carbohydrate was replaced b y a mixture of fructose/glucose/saccharose to match the sugar supply from t he apples. The lipid source was corn oil and the dietary supply of vitamin E was reduced to 1/3 of the recommended value. The rats were sampled after 21 days adaptation. The fibre supply of the apple diet was notably low (abo ut 2%); nevertheless, there was a slight but significant cholesterol-loweri ng effect in plasma, as well as in liver where cholesterol esters accumulat e with cholesterol diets. The lipoprotein profile was markedly altered in a pple-fed rats: a reduction of cholesterol in the triglyceride rich lipoprot ein (TGRLP) fraction, together with a rise in the HDL fraction; hence there was a favourable effect in a cardiovascular protection perspective. This w as paralleled by effects of the apple on cholesterol apparent absorption, w hich was markedly depressed, whereas bile acid digestive balance was unaffe cted. In parallel, there was a positive effect of the apple diet on paramet ers of oxidative stress prevention: higher FRAP plasma levels than in contr ols, together with a reduced MDA excretion in urine. In conclusion, the pre sent work indicates that a moderate supply of dessert apples elicits intere sting effects on lipid and peroxidation parameters. (C) 2001 Elsevier Scien ce Ltd. All rights reserved.