Background: Conjugated linoleic acids (CLA) are naturally occurring fatty acids that have multiple biological properties including the regulation of metabolic, proliferative and immune processes.
Objective: The aim of this study was to investigate the efficacy and safety of CLA as a dietary supplement in mild asthma.
Methods: This was a prospective, randomized, double-blind, placebo-controlled study. Twenty-eight adult subjects (aged 19-40 years) with mild asthma (FEV(1)>70% predicted) were randomized to CLA 4.5 g/day or placebo for 12 weeks in addition to usual treatment. On average, subjects were overweight with a mean body mass index (BMI) of 27.9 kg/m(2).
Results: Subjects in the CLA group had a significant improvement in airway hyperresponsiveness (AHR) at week 12 compared with week 0 [PC(20) 6.6 (2.1) mg/mL vs. 2.2 (0.7) mg/mL; P<0.05]. The CLA group had a significant reduction in weight and BMI compared with placebo and this was associated with a reduction in leptin/adiponectin ratio. There were no differences in systemic cytokine levels, induced sputum cell counts, quality-of-life scores or adverse events.
Conclusions: CLA treatment as an adjunct to usual care in overweight mild asthmatics was well tolerated and was associated with improvements in AHR and BMI.