Zinc and Alzheimer's Disease: An Update

Zinc is an essential metal in human nutrition. A growing number of observations have implicated zinc in the pathophysiology of Alzheimer's disease (AD). Zinc binds and interacts with both the amyloid-β peptide (the major component of senile plaques) and its larger parent protein known as amyloid precursor protein. Nevertheless, the pathophysiological position of zinc in AD remains unclear. Recently, much research has been published that supports the involvement of zinc in AD pathophysiology. Consistent reports show cerebral zinc to be elevated in selected regions of AD brain, and is highly concentrated within senile plaques. Quantitative assessment of zinc in plaques estimates the zinc concentration to be enriched to the near millimolar concentration range. Furthermore, zinc is also detected in neurons that are positively identified to contain neurofibrillary tangles. This paper reviews current available data that indicate a role for zinc in AD pathology.