Ultra-processed diet, systemic oxidative stress, and breach of immunologic tolerance

•Globally, the consumption of ultra-processed foods is increasing.•An ultra-processed diet is associated with biochemical alterations such as oxidative stress, inflammation, and intestinal dysbiosis.•The prooxidative and inflammatory environment could be a factor that affects the configuration of immune cells.•A possible connection between diet, systemic oxidative stress, and the immune system could implicate a lower tolerance of the immune system and an increased risk of infections. In recent years, consumption of ultra-processed food around the world has been increasing. The nutritional profile of an ultra-processed diet is associated with the development of cellular alterations that lead to oxidative stress. The chronic prooxidative state leads to an environment that influences the proliferation, apoptosis, and signaling pathways of immune cells. Likewise, the decrease in the transcription factor NRF2, owing to exacerbated production of reactive oxygen species, leads to changes in immune function and response to infections. This review aims to analyze the connection between an ultra-processed diet, systemic oxidative stress, and immune tolerance, as a contribution to the scientific evidence on the impact of oxidative stress on health and the possible risk of infections—an important consideration in the association of eating pattern and the immune response. [Display omitted]