Butters rich either in trans-10-C18:1 or in trans-11-C18:1 plus cis-9, trans-11 CLA differentially affect plasma lipids and aortic fatty streak in experimental atherosclerosis in rabbits

Dairy fat contains high amounts of saturated fatty acids (FA), which are associated with cardiovascular disease (CVD) risk. Manipulation of dairy cows nutrition allows to decrease the saturated FA content of milk fat, and is associated with increases either in conjugated linoleic acid (CLA) and trans-11-C18:1 contents, or in trans-10-C18:1 content. CLA putatively exhibits beneficial properties on CVD risk, whereas trans FA are suspected to be detrimental. The present study compared the effects of a trans-10-C18:1-rich buffer (T10 buffer), a trans-11-C18:1 + CLA-rich butter (T11-CLA buffer) and a standard butter (S butter) on lipid parameters linked to the CVD risk and fatty streaks. Thirty-six White New Zealand rabbits were fed one of the three butters (12% of the diet, plus 0.2% cholesterol) for 6 (experiment 1) or 12 (experiment 2) weeks. Liver lipids, plasma lipids and lipoprotein concentrations (experiments 1 and 2) and aortic lipid deposition (experiment 2) were determined. The T10 buffer increased VLDL-cholesterol compared with the two others, and total and VLDL-cholesterol compared with the T11-CLA buffer (P < 0.05). The T10 buffer also increased non-HDL/HDL ratio and aortic lipid deposition compared with the T11-CLA buffer (P < 0.05). The T11-CLA butter non-significantly reduced aortic lipid deposition compared with the S butter, and decreased HDL-cholesterol and increased liver triacyglycerols compared with the two other butters (P < 0.05). These results suggest that, compared with the S butter, the T10 butter had detrimental effects on plasma lipid and lipoprotein metabolism in rabbits, whereas the T11-CLA buffer was neutral or tended to reduce the aortic lipid deposition.