Thursday Aug 22, 2013 (foodconsumer.org) - Copper is a nutrient that humans need.  But a study suggests too much copper in the body may promote neurodegeneration in patients who suffer Alzheimer's disease or increase the risk of developing the disease in the first place.

The study published in Biomedical Spectroscopy and Imaging indicates excess copper may be neurotoxic or at least a biomarker for early abnormality.  The study per se could not determine whether copper is simply a biomarker for neurodegeneration or a cause for neurodegeneration.

Using synchrotron x-ray fluorescence microscopy, researchers determined that copper in amyloid plaques, which are the hallmark of Alzheimer's disease, in one group of mice with Alzheimer's disease, was 25% higher than another group of mice who did not show neurodegeneration.

"Since excess copper should not be 'free' in the brain to bind to the plaques, these data suggest that the cellular control of copper is altered in AD (Alzheimer's disease), which may lead to toxic reactions between free copper ions and neurons," said lead investigator Lisa M. Miller, PhD, at Brookhaven National Laboratory. 

Dr. Miller and colleagues have found in their early work that human Alzheimer's disease plaques contain very high levels of copper.

Some foods such as sesame seeds, cashews, soybeans, barley, sunflower seeds, tempeh, Garbanzo beans, lentils, lima Beans, and pumpkin seeds contain higher levels of copper than others.  Copper from foods may not reach a level to pose a risk.

Copper contamination in food, drinking water and the environment may be a risk factor for Alzheimer’s disease should a causal relation between elevated levels of copper and the severity of Alzheimer's disease or neurodegeneration be confirmed. (David Liu)