Effect of Dietary Supplementation with Conjugated Linoleic Acid on Bone Mineral Density, Bone Metabolism Markers and Inflammatory Markers in Healthy Post-menopausal Women: a Randomized Double Blind Pl

Introduction: Conjugated linoleic acid (CLA) has been shown to positively influence calcium and bone metabolism in experimental animals and cell culture, but there are limited human data available. Material and Methods: The study consisted of a double-blind, placebo-controlled trial in which 76 healthy post- menopausal women (aged 55.1) were randomly assigned to receive daily either four capsules CLA G80 containing 3.2 g isomer blend (50:50% cis-9, trans-11: trans-10, cis-12 isomers) or four capsules containing high oleic sunflower oil as placebo for 12 weeks. Urine and blood samples were collected at weeks 0 and 12 and were analyzed for biomarkers of calcium and bone metabolism and inflammatory markers (TNF-? and IL-6). Subjects completed 3-days dietary records during the trial, in weeks 0 (baseline), 6 and 12. Results: Supplementation with 3.2 g CLA isomer blend (50:50% cis-9,trans-11:trans-10,cis-12 isomers) for 12 weeks had no significant effects on markers of bone formation (serum osteocalcin, bone-specific alkaline phosphatase) or bone resorption (urine C-telopeptide-related fraction of type 1 collagen degradation products), PTH, urinary calcium, urinary creatinine and CTP to creatinine ratio. And serum interleukine-6 did not change significantly over 12 weeks in postmenopausal women. Conclusion: Under the conditions tested in this double-blind, placebo-controlled trial in postmenopausal women, 3.2 g CLA isomer blend (50:50% cis-9, trans-11: trans-10, cis-12 isomers) did not affect markers of bone metabolism and calcium.