title: Conjugated linoleic acid is related to bone mineral density but does not affect parathyroid hormone in men.
abstract: The relationships between conjugated linoleic acid (CLA) status, bone, body composition, and the effect of CLA on calciotropic hormones are unclear. A cross-sectional study was designed to examine the association between c9, t11 CLA status in erythrocyte membranes (RBC) and body composition. This preceded a dose-response trial investigating if c9, t11 CLA affected parathyroid hormone (PTH). It was hypothesized that (1) higher c9, t11 CLA status in RBC will be associated with a lower fat and higher bone mass and that (2) PTH will be reduced by 30% after supplementation of c9, t11 CLA. Fifty-four men (age, 19-53 years) were included in the cross-sectional analysis, of which 31 were studied in the dose-response trial and randomized to 1 of 3 groups: placebo (n = 10), 1.5 g/d (n = 11), or 3.0 g/d (n = 10) of c9, t11 CLA for 16 weeks. Men with RBC c9, t11 CLA status above the median had higher whole body bone mineral density (BMD) (1.359 ± 0.024 vs 1.287 ± 0.023 g/cm(2); P = .04) and whole body lean mass (WBL) percentage (78.8% ± 0.9% vs 75.3% ± 1.0%; P = .01), whereas body mass index (24.8 ± 0.5 kg/m(2) vs 27.3 ± 0.9 kg/m(2); P = .01) and whole body fat mass percentage (17.3% ± 0.9% vs 21.3% ± 1.1%; P = .007) were lower. In regression analysis, RBC c9, t11 CLA status accounted for a significant proportion (r(2) = 0.10) of the variation in whole body BMD (P = .03). There were no time or treatment differences among any bone or biomarkers of bone metabolism including PTH. These findings indicate that RBC c9, t11 CLA status, a reflection of long-term (~4 months) dietary CLA intake, positively relates to BMD. However, c9, t11 CLA supplementation does not appear to affect PTH in healthy men.
authors.affiliation: School of Dietetics and Human Nutrition, McGill University, Montreal, Quebec, Canada.
authors.forename: Jason R
authors.initials: JR
authors.lastname: Deguire
authors.forename: Nour
authors.initials: N
authors.lastname: Makarem
authors.forename: Catherine A
authors.initials: CA
authors.lastname: Vanstone
authors.forename: Suzanne
authors.initials: S
authors.lastname: Morin
authors.forename: Gustavo
authors.initials: G
authors.lastname: Duque
authors.forename: Hope A
authors.initials: HA
authors.lastname: Weiler
mesh_terms: D000273:Adipose Tissue / Q000187:drug effects; D000328:Adult; D015415:Biomarkers / Q000097:blood; D001823:Body Composition / Q000187:drug effects*; D001825:Body Fluid Compartments / Q000187:drug effects; D015992:Body Mass Index; D015519:Bone Density / Q000187:drug effects*; D001842:Bone and Bones / Q000187:drug effects*; D002462:Cell Membrane; D003430:Cross-Sectional Studies; D004041:Dietary Fats / Q000097:blood / Q000494:pharmacology*; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D004912:Erythrocytes / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D044243:Linoleic Acids, Conjugated / Q000097:blood / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D009752:Nutritional Status; D010281:Parathyroid Hormone / Q000097:blood*; D012044:Regression Analysis
chemical_list: D015415:Biomarkers; D004041:Dietary Fats; D044243:Linoleic Acids, Conjugated; D010281:Parathyroid Hormone; C046938:9,11-linoleic acid