Superoxide dismutase (SOD) is an endogenous antioxidant enzyme that catalyzes the dismutation of superoxide radicals into oxygen and hydrogen peroxide, thus protecting cells from oxidative stress. Oxidative stress is implicated in the pathogenesis of neurodegenerative diseases, including various forms of dementia such as Alzheimer's disease. Several preclinical studies have shown that decreased SOD activity may contribute to neurodegenerative processes, and animal models have demonstrated that enhancing SOD activity can reduce oxidative damage and improve cognitive outcomes. However, when it comes to clinical evidence in humans, the data are limited and mixed. Some small-scale clinical trials have investigated oral supplementation of SOD (often in the form of melon extract or other bioavailable formulations) and reported modest improvements in cognitive function or oxidative stress markers in elderly populations. Still, these studies tend to have methodological limitations, such as small sample sizes, short durations, and lack of robust controls. There is currently insufficient high-quality clinical evidence to firmly recommend SOD supplementation as a treatment or preventive measure for dementia. While the scientific rationale is plausible and there is some preliminary evidence, larger and more rigorous human trials are needed to clarify its efficacy and safety for dementia. Thus, the evidence level is rated as 2 out of 5.