As you probably know, Alzheimer's disease strikes when neurons, or nerve cells in the brain, die off. One indicator of Alzheimer's is the accumulation in the brain of a protein known as amyloid beta. Clumps of this protein form what is identified as amyloid plaques in the brains of those with Alzheimer's. Neuroscientists have been exploring the potential role dietary metals, such as copper and iron, play in the formation of these plaques.

These researchers are trying to determine whether the presence of excess amounts of metals in the brain actually cause or contribute to the degeneration seen in Alzheimer's or whether they are markers that signal the presence or potential of disease.

What Researchers Know About Alzheimers and Copper

Researchers at the University of Rochester Medical Center found that, over long periods of time, copper from the diet and the environment can accumulate in the cell walls of blood vessels in the brain. This accumulation interferes with the blood-brain barrier system that normally oversees what can and cannot enter or leave the brain through the bloodstream. As a result of this interference, amyloid beta cannot be removed properly and builds up in the brain.

Normally, copper does not travel freely in the brain. But in Alzheimer's disease, the researchers found that after disrupting the blood-brain barrier system, copper moves directly into brain tissue, where it contributes to the production of even more amyloid beta and causes more clumping of the protein into dense plaques. Copper also appears to cause inflammation in brain tissue, which may further accelerate the disease process.

Dietary Sources of Copper and How Much Is Too Much

Copper comes into the diet from a variety of food sources, such as red meat, shellfish, nuts, fruits, and vegetables. It is also found in water that runs through copper pipes and is added to some vitamin-and-mineral supplements. It is an essential nutrient—we need copper for bone development, hormone secretion, nerve conduction, energy production, a healthy immune system, and other body functions. The question is: how much copper is enough for the body to function properly, and how much is too much and may not be safe for some people?

Rashid Deane, PhD, research professor in the Department of Neurosurgery at University of Rochester and lead researcher in the copper study, says more research is needed to answer that question. "We just don't know enough yet to determine the appropriate level of copper, or if diet will ultimately play a role in controlling Alzheimer's disease," he says. "The next step is figuring out how much copper is enough to strike the right balance between too little and too much."

Rashid Deane, BSc, PhD, reviewed this article.


Singh I, Sagare A, Coma M, et al. "Low Levels of Copper Disrupt Brain Amyloid-B Homeostasis by Altering its Production and Clearance." Proceedings of the National Academy of Sciences of the United States of America. 19 August 2013, doi:10.1073pnas.1302212110.

Squitti R, Simonelli I, Ventriglia M, et al. "Meta-Analysis of Serum Non-Ceruloplasmin Copper in Alzheimer's Disease." Journal of Alzheimer's Disease 2013 Sept 26 (Epub ahead of print).