Selenium and asthma: a complex relationship

Descriptive studies in humans investigating the relationship between selenium (Se) status and asthma have presented inconsistent results. The concept of low Se status as a potential risk factor for increased prevalence or severity of asthma is based on the role that Se, through its incorporation into selenoproteins, plays as a potent antioxidant capable of augmenting the oxidative stress that accompanies asthma. However, Se intake also exerts a significant influence over immune responses. Thus, the dual effects of Se status on controlling oxidative stress in the lungs and regulating T helper 2 responses that drive allergic asthma, as well as which selenoproteins are key to regulating these processes, must be considered when attempting to decipher the relationship between this essential nutrient and complex allergic diseases such as asthma.