Understanding the molecular mechanisms of neurodegeneration represents a scientific priority as it will allow scientists to more specifically target and simultaneously interrupt the multiple pathologic mechanisms that contribute to the progression of dementia in Alzheimers disease (AD). Oxidative stress represents one of the key processes in AD pathogenesis, related to formation of both amyloid plaques and neurofibrillary tangles as well as to alteration of many biomolecules. For this reason several antioxidant molecules have been tested in in vitro and in vivo studies in order to detect more efficacious treatments. Dietary antioxidants seem also to have an important role in AD prevention, as shown by several epidemiological studies. Ongoing clinical trials to assess whether antioxidant supplementation has a role in primary prevention of AD or in delaying the progression of disease in individuals with Mild Cognitive Impairment (MCI), are in progress or planned. Thus, research involving new antioxidants and their potential clinical applications will provide new insights into the molecular basis of neuroprotective mechanisms that may be relevant to AD and other age-related neurodegenerative disorders.