SIMILAR SERUM-LIPOPROTEIN CHOLESTEROL CONCENTRATIONS IN HEALTHY-SUBJECTS ON DIETS ENRICHED WITH RAPESEED AND WITH SUNFLOWER OIL

A double-blind cross-over study was conducted during two 3-week period s to compare the effects of rapeseed oil and sunflower oil, enriching a normal diet, on the lipoprotein and fatty acid composition in health y subjects. It was carried out in randomized order at residential scho ols, comprising 101 persons (mean age 29.2 years). The dietary fats us ed for cooking and as table margarine were prepared from rapeseed oil during one period and from sunflower oil during the other. No changes were made in the total fat content or other dietary nutrients. During both treatment periods the serum cholesterol (-4%, P < 0.001), LDL cho lesterol (-5% to -7%, P < 0.01 and 0.001) and apolipoprotein B (-5%, P < 0.001) concentrations significantly and to the same extent, while s erum triglycerides, HDL cholesterol, apolipoprotein A-1 and lipoprotei n (a) remained virtually unchanged. The content of 18:2 n-6 serum phos pholipids was increased after the sunflower oil-enriched diet, and the contents of oleic acid (18:1 n-9), alpha-linolenic acid (18:3 n-3), a nd eicosapentaenoic acid (20:5 n-3) were increased after the rapeseed oil-enriched diet. The concentration of alpha-tocopherol increased and gamma-tocopherol decreased after the sunflower oil-enriched diet, les s so after the rapeseed oil-enriched diet. It is concluded that substi tution of mono- and polyunsaturated fats for saturated fats without an y other dietary changes causes a significant improvement of the lipopr otein profile in healthy subjects. The rapeseed oil and sunflower oil fats were equally effective in this respect. The results also indicate that humans have a certain capacity to elongate and desaturate alpha- linolenic acid to 20:5 n-3 in vivo. Dietary fats based on rapeseed oil seem to be attractive alternatives to the more commonly used oils and fats rich in linoleic acid. Financial support from the Swedish Counci l for Forestry and Agricultural Research and the Swedish Margarine Ind ustrial Association for Nutritional Physiological Research is grateful ly acknowledged.