Does fat in milk, butter and cheese affect blood lipids and cholesterol differently?

To compare the effects of isoenergetic amounts of milk, cheese and butter (adjusted to the same content of lactose and casein) on fasting and postprandial blood lipids and lipoproteins, and on postprandial glucose and insulin response. The experiments were designed to provide 20% of total energy from dairy fat, as either whole milk, mean (+/-SD) 2164 (+/-97) g, butter 93 (+/-4) g, and hard cheese 305 (+/-45) g, which were served to 14 healthy young men for three periods of three weeks each, separated by washout periods, in a randomized, cross-over study with strictly controlled dietary intake. Fasting blood samples were taken at the end of the study periods. Measurements of the postprandial effect of the three different dairy test products (0.7 g of milk fat/kg body weight) were carried out on day 4 of each intervention period. Blood samples were taken before and at 2, 4, 6 and 8 hours following intake of the meals. Fasting LDL cholesterol concentration was significantly higher after butter than cheese diet (p = 0.037), with a borderline significant difference in total cholesterol (p = 0.054) after the experimental periods of three weeks. Postprandial glucose showed a higher response after cheese diet than after milk diet (p = 0.010, diet x time interaction). A different effect of fat in milk and butter could not be confirmed in this study. The moderately lower LDL cholesterol after cheese diet compared to butter diet should be investigated further.