title: Conjugated linoleic acids reduce body fat in healthy postmenopausal women.
abstract: Isomers of conjugated linoleic acids (CLA) reduce fat mass (FM) and increase insulin sensitivity in some, but not all, murine studies. In humans, this effect is still debatable. In this study, we compared the effect of 2 CLA supplements on total and regional FM assessed by dual energy X-ray absorptiometry, changes in serum insulin and glucose concentrations, and adipose tissue (AT) gene expression in humans. In a double-blind, parallel, 16-wk intervention, we randomized 81 healthy postmenopausal women to 1) 5.5 g/d of 40/40% of cis9,trans11-CLA (c9,t11-CLA) and trans10,cis12-CLA (t10,c12-CLA) (CLA-mix); 2) cis9, trans11-CLA (c9,t11-CLA); or 3) control (olive oil). We assessed all variables before and after the intervention. The CLA-mix group had less total FM (4%) and lower-body FM (7%) than the control (P = 0.02 and < 0.001, respectively). Post hoc analyses showed that serum insulin concentrations were greater in the CLA-mix group (34%) than the control group (P = 0.02) in the highest waist circumference tertile only. AT mRNA expression of glucose transporter 4, leptin, and lipoprotein lipase was lower, whereas expression of tumor necrosis factor-alpha was higher in the CLA-mix group than in the control group (P < 0.04). In conclusion, a 50:50 mixture of c9,t11- and t10,c12-CLA isomers resulted in less total and lower-body FM in postmenopausal women and greater serum insulin concentrations in the highest waist circumference tertile. Future research is needed to confirm the insulin desensitizing effect of the CLA mixture and the effect on the mRNA expression of adipocyte-specific genes in humans.
authors.affiliation: Department of Human Nutrition, Faculty of Life, University of Copenhagen, Frederiksberg 1958, Denmark. mrf@life.ku.dk
authors.forename: Marianne
authors.initials: M
authors.lastname: Raff
authors.forename: Tine
authors.initials: T
authors.lastname: Tholstrup
authors.forename: Søren
authors.initials: S
authors.lastname: Toubro
authors.forename: Jens M
authors.initials: JM
authors.lastname: Bruun
authors.forename: Pia
authors.initials: P
authors.lastname: Lund
authors.forename: Ellen M
authors.initials: EM
authors.lastname: Straarup
authors.forename: Robin
authors.initials: R
authors.lastname: Christensen
authors.forename: Maria B
authors.initials: MB
authors.lastname: Sandberg
authors.forename: Susanne
authors.initials: S
authors.lastname: Mandrup
mesh_terms: D052242:Adiponectin / Q000097:blood; D000273:Adipose Tissue / Q000033:anatomy & histology / Q000187:drug effects*; D001786:Blood Glucose / Q000378:metabolism; D001835:Body Weight; D005227:Fatty Acids / Q000378:metabolism; D005260:Female; D006304:Health Status; D006801:Humans; D007328:Insulin / Q000097:blood; D044243:Linoleic Acids, Conjugated / Q000494:pharmacology*; D000069463:Olive Oil; D010349:Patient Compliance; D010938:Plant Oils / Q000494:pharmacology; D017698:Postmenopause; D012333:RNA, Messenger / Q000235:genetics; D011795:Surveys and Questionnaires; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics; D055105:Waist Circumference
chemical_list: D052242:Adiponectin; D001786:Blood Glucose; D005227:Fatty Acids; D007328:Insulin; D044243:Linoleic Acids, Conjugated; D000069463:Olive Oil; D010938:Plant Oils; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha