Dietary interventions in asthma

Asthma is a chronic inflammatory disorder of the airways. The inflammatory response in asthma is heterogeneous. Allergen specific responses lead to activation of the acquired immune system, via a predominantly IL-5 mediated, eosinophilic pathway. Stimuli such as viruses and bacteria activate the innate immune system, via a predominantly IL-8 mediated, neutrophilic pathway. Asthma has also been demonstrated to involve a systemic inflammatory component. Glucocorticoids are the predominant pharmacological treatment used to control inflammation in asthma. However, compliance with medications can be compromised due to patient concerns about side effects. Hence dietary interventions that target the inflammatory response in asthma have great potential. Various aspects of dietary intake are known to modulate inflammation. Saturated fatty acids can induce an inflammatory response via activation of pattern recognition receptors. Omega-3 fatty acids can be anti-inflammatory, via mechanisms such as modification of eicosanoid production. Antioxidants can have anti-inflammatory effects as they scavenge free radicals, preventing activation of transcription factors including NF-κB. Chronic excess energy intake can lead to obesity, which augments inflammation due to the release of inflammatory mediators by adipose tissue. Here we review the role of these dietary components in asthma.