Oxidative Stress, Environmental Pollution, and Lifestyle as Determinants of Asthma in Children

Simple Summary This review is focused on the role of oxidative stress in childhood asthma. The term "oxidative stress" indicates an imbalance between production of radical oxygen species and antioxidant defense systems. Cigarette smoke, allergens, viruses, and other environmental contaminants, as well as a detrimental lifestyle, elevate airway oxidative stress. Uncontrolled oxidative stress within airways amplifies inflammatory responses and tissue damage and alters immune responses, thus increasing the risk of asthma onset and asthma progression in children. Early lifestyle and dietary interventions and use of new antioxidant therapies to restore oxidant/antioxidant balance are all valuable strategies to preserve airway homeostasis. Exposure to cigarette smoke, allergens, viruses, and other environmental contaminants, as well as a detrimental lifestyle, are the main factors supporting elevated levels of airway oxidative stress. Elevated oxidative stress results from an imbalance in reactive oxygen species (ROS) production and efficiency in antioxidant defense systems. Uncontrolled increased oxidative stress amplifies inflammatory processes and tissue damage and alters innate and adaptive immunity, thus compromising airway homeostasis. Oxidative stress events reduce responsiveness to corticosteroids. These events can increase risk of asthma into adolescence and prompt evolution of asthma toward its most severe forms. Development of new therapies aimed to restore oxidant/antioxidant balance and active interventions aimed to improve physical activity and quality/quantity of food are all necessary strategies to prevent asthma onset and avoid in asthmatics evolution toward severe forms of the disease.