Vitamin E Isoform-Specific Functions in Allergic Inflammation and Asthma

Asthma and allergic lung disease occur as complex environmental and genetic interactions. Epidemiological studies and randomized prevention trials have demonstrated the potential of a number of protective dietary factors for asthma, including the vitamin E isoform γ-tocopherol. However, reports for vitamin E have seemingly varied outcomes regarding benefits. These seemingly varied outcomes are consistent with mechanistic studies of opposing functions of the vitamin E isoforms γ-tocopherol and γ-tocopherol. Moreover, the variation in global prevalence of asthma may be explained, at least in part, by tocopherol isoforms. To clearly interpret outcomes of preclinical models and clinical studies, the studies need to include measurements of the tocopherol isoforms in the supplements, in vehicles for the supplements, and in the plasma or tissues before and after intervention. Understanding the differential regulation of inflammation by tocopherol isoforms provides a basis toward designing interventions that more effectively modulate inflammatory pathways and improve lung function in disease. Furthermore, the investigation of early life diet, in relation to childhood asthma, raises the possibility of early life dietary interventions.