Cis-9, trans- 11 and trans-10, cis-12 conjugated linoleic acid (CLA) do not affect the plasma lipoprotein profile in moderately overweight subjects with LDL phenotype B

Abstract Background Results of a pilot study suggested that cis -9, trans -11 conjugated linoleic acid (CLA) improved LDL phenotype in moderately overweight subjects with LDL phenotype B. Objective Initiated by the results of this pilot study, we have specifically designed a study to test the hypothesis that cis -9, trans -11 conjugated linoleic acid improves LDL phenotype in moderately overweight subjects with LDL phenotype B. Effects on the serum lipid profile, on plasma glucose and insulin concentrations, and on clinical parameters were also examined. Design Volunteers with LDL phenotype B were divided into three groups consuming daily a drinkable dairy product not enriched with CLA (placebo, n  = 34), the same dairy product enriched with 3 g c9, t11 CLA ( n  = 34), or the dairy product enriched with 3 g t10, c12 CLA ( n  = 19) for 13 weeks. Results Median changes in the proportions of plasma small dense LDL were −2.0% in the control group and −0.1% in the c9, t11 CLA and t10, c12 CLA groups ( p  = 0.981 for the differences between the groups). c9, t11 CLA or t10, c12 CLA did also not affect serum concentrations of LDL and HDL cholesterol, and of triacylglycerol, and plasma concentrations of glucose and insulin. Conclusions In humans with LDL phenotype B, c9, t11 CLA and t10, c12 CLA do not beneficially change risk factors for cardiovascular disease or diabetes.