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.

Advanced glycation end-products (AGEs) are a variety of endogenous and exogenous substances that play an important role in inflammation, allergies, and autoimmune diseases. AGEs’ pathogenicity, alongside advanced oxidation protein products (AOPPs) and other ligands, lies in their ability to bind the receptor for advanced glycation end-products (RAGE) and trigger pro-inflammatory signaling pathways and cytokine release. The literature reports numerous studies on the role of the AGE-RAGE axis in various allergic conditions, including bronchial asthma, atopic dermatitis, food allergies, and autoimmune diseases such as rheumatoid arthritis, systemic lupus erythematosus, or Hashimoto’s thyroiditis, where the significant role of the AGE–RAGE axis in the immunopathogenesis of both allergic and autoimmune conditions is largely discussed and demonstrated. They suggest promising opportunities for the development of new diagnostic markers and targeted therapeutic strategies. However, further large-scale studies are needed to fully understand this multifaceted pathway and translate these insights into effective clinical interventions.

Oxidative stress occurs when reactive oxygen species exceed the capacity of antioxidant defenses, causing molecular damage and alterations in cellular signaling. This process is characterized by interindividual variability, particularly based on biological sex. Hormones such as estrogens, which exert antioxidant effects, and androgens, which can act as pro-oxidants in certain contexts, along with genetic and epigenetic factors linked to sex chromosomes, contribute to the sex-specific regulation of redox homeostasis. Nutraceuticals, including polyphenols, vitamins, carotenoids, and omega-3 fatty acids, influence oxidative processes through both direct and indirect mechanisms. This review evaluates the impact of biological sex on oxidative stress mechanisms and responses to nutraceutical antioxidants, synthesizing the results of molecular, metabolic, and clinical studies published over the past decade. The current literature indicates that biological sex influences both basal redox balance and individual responses to antioxidant mechanisms. Generally, males have a higher oxidative load and may benefit more from supplementation, while females typically possess greater antioxidant capacity, primarily due to hormonal influences. Greater consideration of sex as a biological variable is essential to optimize nutraceutical strategies and develop personalized interventions for oxidative stress-related diseases.