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

Clin Exp Allergy. 2010 Jul;40(7):1071-8. doi: 10.1111/j.1365-2222.2010.03531.x.


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.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Anti-Asthmatic Agents / therapeutic use*
  • Asthma / complications*
  • Asthma / drug therapy*
  • Asthma / immunology
  • Dietary Supplements
  • Double-Blind Method
  • Female
  • Humans
  • Linoleic Acids, Conjugated / therapeutic use*
  • Male
  • Overweight / complications*


  • Anti-Asthmatic Agents
  • Linoleic Acids, Conjugated