Environmental Copper Exposure Linked to Alzheimer's Disease

A new study suggests that copper exposure at normal dietary levels from a variety of sources is a major environmental cause of Alzheimer's Disease.

"It is clear that, over time, copper's cumulative effect is to impair the systems by which amyloid beta is removed from the brain," said Rashid Deane, Ph.D., a research professor in the University of Rochester Medical Center (URMC) Department of Neurosurgery, member of the Center for Translational Neuromedicine, and the lead author of the study. "This impairment is one of the key factors that cause the protein to accumulate in the brain and form the plaques that are the hallmark of Alzheimer's disease."

Copper's presence in the food supply is ubiquitous. It is found in drinking water carried by copper pipes, nutritional supplements, and in certain foods such as red meats, shellfish, nuts, and many fruits and vegetables. The mineral plays an important and beneficial role in nerve conduction, bone growth, the formation of connective tissue, and hormone secretion.

However, the new study shows that copper can also accumulate in the brain and cause the blood brain barrier -- the system that controls what enters and exits the brain -- to break down, resulting in the toxic accumulation of the protein amyloid beta, a by-product of cellular activity. Using both mice and human brain cells Deane and his colleagues conducted a series of experiments that have pinpointed the molecular mechanisms by which copper accelerates the pathology of Alzheimer's disease.

Reference: Itender Singh, Abhay P. Sagare, Mireia Coma, David Perlmutter, Robert Gelein, Robert D. Bell, Richard J. Deane, Elaine Zhong, Margaret Parisi, Joseph Ciszewski, R. Tristan Kasper, and Rashid Deane. Low levels of copper disrupt brain amyloid-β homeostasis by altering its production and clearance. PNAS, August 19, 2013 DOI:10.1073/pnas.1302212110