The Diet-Multiple Sclerosis Connection: Oxidative Stress and Emerging Mechanisms.

Multiple sclerosis (MS) is an autoimmune neuroinflammatory disease resulting in myelin degeneration and progressive disability. Oxidative stress plays a crucial role in MS pathogenesis and progression. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a master regulator of the antioxidant mechanisms and its upregulation is associated with beneficial effects in MS. Among the environmental factors influencing MS onset and progression, diet represents a promising non-pharmacological strategy to modulate Nrf2, potentially improving MS outcomes. Indeed, several natural compounds present in Mediterranean, ketogenic and Paleolithic diets can enhance Nrf2 activity, and exert beneficial effects in preclinical models of MS. In this review, we summarize the key role of oxidative stress in MS and highlight how dietary regimens and Nrf2-modulating natural compounds might have therapeutic potential for MS patients. Additionally, we discuss emerging and still poorly explored mechanisms beyond classical Nrf2 activation, including epigenetic regulation and the stability of DNA/RNA secondary structures known as G-quadruplexes, which are involved in gene expression regulation and may represent novel nutrition-based therapeutic targets. However, while Nrf2 modulation by diet is supported by preclinical and limited clinical evidence, targeting G-quadruplexes as a strategy to counteract oxidative stress in MS remains largely speculative and requires further investigation. Notably, epigenetic mechanisms and G-quadruplexes may represent innovative targets of Nrf2-boosting dietary natural compounds for the development of supplemental therapeutic strategies for MS.