The electromagnetic waves emitted by mobile phones could protect against and even reverse Alzheimer's disease, according to a US study.

Researchers at the University of South Florida exposed 96 mice, most of whom had been genetically altered to develop the Alzheimer's disease as they aged, to electromagnetic waves generated by mobile phones.

The mice were zapped with 918-megaherz of frequency twice a day for an hour each time over nine months - the equivalent of several decades in humans.

In older mice with Alzheimer's, long-term exposure to the electromagnetic fields caused the erasure of deposits of beta-amyloid - a protein fragment that accumulates in the brain of Alzheimer's sufferers to form the disease's signature plaques.

Memory impairment in the older mice disappeared, too, the study showed.

It also found that young adult mice with no apparent signs of memory impairment were protected against Alzheimer's disease after several months of exposure to the mobile phone waves.

The memory levels of normal mice with no genetic predisposition for Alzheimer's disease were also boosted after exposure to the electromagnetic waves.

The study was the first to look at the long-term effects of mobile phone exposure in mice or humans, and its findings took the researchers by surprise.

"I started this work with a hypothesis that the electromagnetic fields would be deleterious to Alzheimer's mice," lead author Professor Gary Arendash said.

"When we got our initial results showing a beneficial effect, I thought, 'give it a few more months and it will get bad for them'.

"It never got bad. We just kept getting these beneficial effects in both the Alzheimer's and normal mice."

Based on the findings, the researchers are hopeful electromagnetic field exposure could be an effective, non-invasive and drug-free way to prevent and treat Alzheimer's in humans.

- AFP