Study links copper to Alzheimer's disease

US researchers said that too much copper in diets may play a role in fueling the abnormal protein build-up that are contributing to Alzheimer's disease, according to media reports on Tuesday.

While copper is important to healthy nerve conduction, hormone secretion and the growth of bones and connective tissue, researchers from the University of Rochester Medical Center suggested that the mineral interfered with the brain's shielding - the blood brain barrier.

Copper is found in a wide range of the foods we eat, including red meat, shellfish, nuts and many fruits and vegetables, as well as in many vitamin supplements.

A study on mice showed that when mice were fed more copper in their water, they had a greater build-up of the metal in the blood vessels in the brain.

And this interfered with the way the barrier functioned and made it harder for the brain to get rid of a protein called beta amyloid, which is one of the hallmarks of Alzheimer's disease.

Lead researcher Dr Rashid Deane said: "It is clear that, over time, copper's cumulative effect is to impair the systems by which amyloid beta is removed from the brain."

Deane's team also found that copper accumulation in the brain causes inflammation in brain tissues.

The researchers noted that the concentration of copper in the brain's small blood vessels increase with age, since the blood-brain barrier becomes "leaky" in the elderly, letting in larger toxic molecules circulating the blood.

Deane said that, in the absence of effective treatments for Alzheimer's disease, his team's findings suggest a way to prevent the memory-robbing disorder or slow it once it has taken hold.

However, some scientists remain cautious about the latest findings.

Chris Exley, professor of bioinorganic chemistry at Keele University, said there was "no true consensus" on the role of copper in Alzheimer's disease.

Dr Doug Brown, from the Alzheimer's Society, said: "Considering copper is a vital mineral for the body, people should treat these results with caution and not cut it out of their diet. More research is needed to understand the role that copper might play in the brain."