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Original Article


Pilot Study of the Effects of n-3 Polyunsaturated Fatty Acids on Exhaled Nitric Oxide in Patients With Stable Asthma


A Moreira,1,2 P Moreira,4 L Delgado,1 J Fonseca,2,3 V Teixeira,4 P Padrão,4 G Castel-Branco2

1 Department of Immunology, Faculty of Medicine, University of Porto, Porto, Portugal
2 Department of Immunoallergology, University Hospital São João, Porto, Portugal
3 Department of Biostatistics and Medical Informatics, Faculty of Medicine, University of Porto, Porto, Portugal
4 Faculty of Nutrition and Food Sciences, University of Porto, Porto, Portugal

J Investig Allergol Clin Immunol 2007; Vol. 17 (5): 309-313



Background: The anti-inflammatory effects of n-3 polyunsaturated fatty acids (n-3 PUFA) have been demonstrated both in vitro and in vivo. The results of epidemiological studies suggest that fi sh consumption has a benefi cial effect on lung function and prevalence of asthma. However, data from intervention trials have not revealed a benefi cial effect of n-3 PUFA supplementation in patients with established disease.

Objective: To study the effects of short-term n-3 PUFA supplementation in addition to maintenance therapy on exhaled nitric oxide in asthmatic patients.

Methods: A double-blind, placebo-controlled trial was undertaken in 20 women with asthma. Patients received either a combination of eicosapentaenoic acid and docosahexaenoic acid plus 10 mg vitamin E or placebo twice daily for 2 weeks. The primary outcome measure was the fraction of exhaled nitric oxide (FeNO) and the secondary outcomes were asthma control (score on the Asthma Control Questionnaire
[ACQ]) and lung function (forced expiratory volume in 1 second [FEV1]).

Results: No significant differences were observed in FeNO, ACQ score, or FEV1 between patients receiving n-3 PUFA supplementation and those receiving placebo.
Conclusions: Short-term dietary supplementation with n-3 PUFA in women with stable asthma was not associated with statistically significant changes in FeNO, asthma control, or lung function

Key words: Asthma. Airway inflammation. n-3 Polyunsaturated fatty acids. Eicosapentaenoic acid. Docosahexaenoic acid. Exhaled nitric oxide.