The current systematic review was conducted to establish the relationship between diets high in iron (Fe) and copper (Cu) and cognitive decline or Alzheimer’s disease (AD). Two meta-analyses, two systematic reviews, 11 placebo-controlled trials, five observational studies, 45 case–control studies, 30 autopsy and five uncontrolled studies, and one case report were identified. Eleven interventional trials tried to either supplement or deplete Fe and Cu but none of them provided clear evidence of a beneficial effect on cognitive performance in patients with AD. The prospective studies revealed an association between a diet simultaneously high in saturated fatty acids (SFA) and Cu and cognitive decline. Case–control and autopsy studies showed elevated Fe levels in the brains of AD patients, whereas the evidence was less consistent for Cu. In most of the studies, Cu concentrations were unchanged in the cerebrospinal fluid and the brain but increased in the serum. The authors concluded that the existing data suggest that diets excessive in Fe or Cu, together with a high intake of SFA, should be avoided in the elderly who are not at risk of anemia. Br J Nutr. 2012 Jan;107(1):7-19. PMID: 21767446
