Conjugated linoleic acid improves airway hyper-reactivity in overweight mild asthmatics.

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.