Comparison of dietary fats - physiological effects of fatty acids

The effects of different fatty acids in vegetable and animal fats/oils are discussed with regard to carcinogenesis, atherogenesis and body fat depots. In experiments with animal models it has been demonstrated that milk fat-based diets produce fewer tumours than polyunsaturated vegetable oil-based diets. Butter is hypercholesterolemic compared with many other fat sources such as margarines (not high-trans margarines) and vegetable oil. There is evidence that whole milk does not affect cholesterol fractions. Conjugated linoleic acids (CLA) were identified as antiatherogenic compounds in ruminant milk fat. Butter contains about 10% short- and medium-chain fatty acids, which are mainly oxidized in the liver. Long-chain fatty acids are directly stored in the fat depots. Furthermore, CLAs (not present in vegetable oils) reduce body fat deposition in animal experiments and increases fatty acid oxidation in muscle cells (higher lean body mass).