a1 Maastricht University, Department of Human Biology, Maastricht, The Netherlands
a2 Laboratoire de Nutrition Humaine, Université d'Auvergne CRNH, Clermont-Ferrand, France
a3 University of Edinburgh, Cardiovascular Research Unit, Edinburgh, Scotland, UK
a4 INRA, Unité de Nutrition Lipidique, Dijon, France
Trans isomers of α-linolenic acid, which are formed by deodorization of refined vegetable oils, can be found in significant amounts in edible oils. Effects of trans α-linolenic acid on plasma lipoproteins are unknown. We therefore investigated the effects of trans α-linolenic acid on plasma lipids and lipoproteins in healthy European men. Eighty-eight healthy men from three European countries (France, Scotland, UK and the Netherlands) first consumed for 6 weeks a diet with experimental oils ‘free’ of trans fatty acids (run-in period). For the next 6 weeks, they were randomly allocated to a diet with experimental oils ‘high’ or ‘low’ in trans α-linolenic acid. Daily total trans α-linolenic acid intake in the high trans group was 1410 (range 583–2642) mg. Experimental oils were provided as such, or incorporated into margarines, cheeses, muffins and biscuits. The high trans α-linolenic acid diet significantly increased the plasma LDL-:HDL-cholesterol ratio by 8.1 % (95 % CI 1.4, 15.3; P=0.02), and the total cholesterol:HDL-cholesterol ratio by 5.1 % (95 % CI 0.4, 9.9; P=0.03) compared with the low-trans diet. This was largely explained by an increase in LDL-cholesterol on the high-trans diet, while no change was observed in the low-trans group (mean treatment effect of 4.7 % (95 % CI -0.8, 10.5; P=0.10). No effects were found on total cholesterol and HDL-cholesterol, triacylglycerols, apolipoprotein B and A-1, and lipoprotein(a) concentrations. In conclusion, trans α-linolenic acid may increase plasma LDL-:HDL-cholesterol and total cholesterol:HDL-cholesterol ratios. Whether diet-induced changes in these ratios truly affects the risk for CHD remains to be established.
(Received February 07 2000)
(Revised September 26 2000)
(Accepted October 03 2000)
† Members of the TransLinE group are: S. H. F. Vermunt, R. P. Mensink, F. J. J. Cox (Maastricht University, Department of Human Biology, Maastricht, The Netherlands), J. L. Sé%bédio, J. M. Chardigny, L. Bretillon (INRA, Unité de Nutrition Lipidique, Dijon, France), R. A. Elton, A. Macvean, R. A. Riemersma (University of Edinburgh, Cardiovascular Research Unit, Edinburgh, Scotland, UK), B. Beaufrère, E. Verdie (Laboratoire de Nutrition Humaine, Université d'Auvergne CRNH, Clermont-Ferrand, France), E. Rock (INRA-U3M, St Genes Champanelle, France), G. Hénon (Lesieur Alimentaire, Neuilly, France), J. P. Noël (CEA-Saclay, Gif sur Yvette, France), J. Niemelä (Raision Margarinii, Raisio, Finland), R. Grappin (INRA-SRTAL, Poligny, France), R. A. Armstrong (Queen Medical College, Edinburgh, Scotland, UK), W. W. Christie, C. Scrimgeour, C. Fernie (Scottish Crop Research Institute, Invergowrie, Dundee, Scotland, UK).