Nutraceuticals Against Oxidative Stress in Allergic Diseases

Antioxidant mechanisms consist of both enzymatic and non-enzymatic compounds, which can be either endogenous or exogenous and play a crucial role in counteracting oxidative stress. These compounds are primarily obtained through the diet. Vegetables, plants, and fruits contain a wide range of alkaloids, polyphenols, and terpenoids, collectively referred to as "phytochemicals." Many of these substances are responsible for the beneficial properties of fruits and vegetables, which are essential components of a healthy lifestyle, contributing to the prevention of chronic diseases and the promotion of longevity. Nutraceuticals are bioactive substances present in food-or its components-that exert positive effects on health and may help prevent or treat various disorders. In this review, we examine the main applications of nutraceuticals in allergic disorders. The literature reports numerous studies on exogenous dietary antioxidant supplementation in various allergic conditions, including bronchial asthma, atopic dermatitis, food allergies, allergic rhino-conjunctivitis, urticaria, and angioedema. In some of these conditions, promising results have been observed. These positive outcomes are generally associated with a reduction in oxidative stress markers, enhancement of antioxidant systems, and, in some cases, anti-inflammatory effects. The administration of exogenous substances through food derivatives or dietary supplements, when scientifically standardized, has been proven to be effective. However, further large-scale, unbiased studies are needed-particularly those that include a broader range of oxidative stress biomarkers.