Nutritional approaches to modulate oxidative stress in Alzheimer's disease

Alzheimer's disease (AD) brain is characterized by amyloid β-peptide (Aβ) deposits, neurofibrillary tangles, synapse loss, and extensive oxidative stress. Aβ-induced oxidative stress is indexed by protein oxidation, lipid peroxidation, free radical formation, DNA oxidation and neuronal cell death. Oxidative stress is combated by antioxidants. Antioxidants and nutrition have long been considered as an approach to slow down AD progression. In this review, we focus on antioxidants that have been shown to protect against Aβ-induced oxidative stress, particularly vitamin E, ferulic acid, various polyphenols, including quercetin and resveratrol, α-lipoic acid, N-acetyl-L-cysteine (NAC), curcumin, epigallocatechin gallate (EGCG), and γ-glutamylcysteine ethyl ester (GCEE). Brain-accessible antioxidants with both radical scavenging properties and ability to induce protective genes are hypothesized to be helpful in treatment for AD.