OBJECTIVES: This study investigated the effect of dietary CLA supplementation (3g/day; 50:50 mix of the two major isomers) on the immune system and plasma lipids and glucose of healthy human (male and female) volunteers. DESIGN: Double-blind, randomized, reference-controlled study. SUBJECT AND INTERVENTION: A total of 28 healthy male and female participants aged 25-50 y received eitherhigh oleic sunflower oil (reference) or 50% CLA 9-11 and 50% CLA 10-12 CLA isomers (50:50 CLA-triglyceride form). The treatments were given as supplements in soft-gel capsules providing a total 3 g (6 x 500 mg capsules) per day in treatment groups for 12 weeks. A 12-week washout period followed the intervention period. RESULTS:Levels of plasma IgA and IgM were increased (P < 0.05 and 0.01 respectively), while plasma IgE levels were decreased (P < 0.05). CLA supplementation also decreased the levels of the proinflammatory cytokines, TNF-alpha and IL-1beta (P < 0.05), but increased the levels of the anti-inflammatory cytokine, IL-10 (P < 0.05). Another aspect of immune function, delayed type hypersensitivity (DTH) response, was decreased during and after CLA supplementation (P < 0.05). However, plasma glucose, lipids, lymphocyte phenotypic results were not affected significantly by CLA. CONCLUSION: This is the first study to show that CLA, a fatty acid naturally found in dairy and meat products, can beneficially affect immune function in healthy human volunteers. SPONSORSHIP: This study was supported by Loders-Croklaan, The Netherlands and SEERAD (Scottish Executive Environmental Rural and Agriculture Department).
RCT Entities:
OBJECTIVES: This study investigated the effect of dietary CLA supplementation (3g/day; 50:50 mix of the two major isomers) on the immune system and plasma lipids and glucose of healthy human (male and female) volunteers. DESIGN: Double-blind, randomized, reference-controlled study. SUBJECT AND INTERVENTION: A total of 28 healthy male and female participants aged 25-50 y received either high oleic sunflower oil (reference) or 50% CLA 9-11 and 50% CLA 10-12 CLA isomers (50:50 CLA-triglyceride form). The treatments were given as supplements in soft-gel capsules providing a total 3 g (6 x 500 mg capsules) per day in treatment groups for 12 weeks. A 12-week washout period followed the intervention period. RESULTS: Levels of plasma IgA and IgM were increased (P < 0.05 and 0.01 respectively), while plasma IgE levels were decreased (P < 0.05). CLA supplementation also decreased the levels of the proinflammatory cytokines, TNF-alpha and IL-1beta (P < 0.05), but increased the levels of the anti-inflammatory cytokine, IL-10 (P < 0.05). Another aspect of immune function, delayed type hypersensitivity (DTH) response, was decreased during and after CLA supplementation (P < 0.05). However, plasma glucose, lipids, lymphocyte phenotypic results were not affected significantly by CLA. CONCLUSION: This is the first study to show that CLA, a fatty acid naturally found in dairy and meat products, can beneficially affect immune function in healthy human volunteers. SPONSORSHIP: This study was supported by Loders-Croklaan, The Netherlands and SEERAD (Scottish Executive Environmental Rural and Agriculture Department).
Authors: Natalie M Racine; Abigail C Watras; Aaron L Carrel; David B Allen; Jennifer J McVean; Robert R Clark; Abigail R O'Brien; Marianne O'Shea; Corey E Scott; Dale A Schoeller Journal: Am J Clin Nutr Date: 2010-03-03 Impact factor: 7.045