Folate deficiency has been associated with age-related neurodegeneration. We demonstrate herein that dietary deficiency in folate and vitamin E, coupled pro-oxidant stress induced by dietary iron, increased amyloid-beta (Abeta) levels in normal adult mice. This increase was potentiated by apolipoprotein E (ApoE) deficiency as shown by treatment of transgenic mice homozygously lacking murine ApoE. Dietary supplementation with apple juice concentrate in drinking water alleviated the increase in Abeta for both mouse genotypes. These findings provide further evidence linking nutritional and genetic risk factors for age-related neurodegeneration, and underscore that dietary supplementation may be useful to augment therapeutic approaches.