Researchers at the University of South Florida (USF) found, to their surprise, that 96 mice they zapped twice daily for an hour each time with electromagnetic waves similar to those generated by US mobile (cellular) phones benefited from the exposure.
Long-term exposure to the electromagnetic waves in mobile phones wiped out deposits of beta-amyloid -- a protein fragment that accumulates in the brain of Alzheimer's sufferers to form the disease's signature plaques -- in older mice and improved their memories, the study published in the Journal of Alzheimer's Disease showed.
Young adult mice with no apparent signs of memory impairment were protected against Alzheimer's disease after several months' exposure to the mobile phone waves, and the memories of normal mice with no genetic predisposition for Alzheimer's disease were boosted after exposure to the electromagnetic waves.
No one was more surprised than the researchers themselves, who had embarked on the tests several years ago, convinced they would show "that the electromagnetic fields from a cell phone would be deleterious to Alzheimer's mice," lead author Gary Arendash, a USF professor, told AFP.
"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," Arendash said.
It took several months of exposure before the benefits were seen in mice, and that would be the equivalent of many years in humans, Arendash said.
The mice in the study didn't wear tiny headsets or have scientists holding mobile phones up to their ears. Instead, their cages were arranged around an antenna that generated a mobile phone signal.
Each animal was housed the same distance from the antenna and exposed to electromagnetic waves equivalent to what is typically emitted by a mobile phone pressed up against a human head.
"Since we selected electromagnetic parameters that were identical to human cell phone use and tested mice in a task closely analogous to a human memory test, we believe our findings could have considerable relevance to humans," Arendash said.
But William Thies, chief medical and scientific officer of the Alzheimer's Association, said the study was "very preliminary" and warned against self-medicating by over-using a cell phone.
"No one should feel they are being protected from Alzheimer's, dementia, cognitive decline by using their cell phones based on this study," Thies said in a statement.
The study "needs to be replicated in animals before we begin to even consider trying it in people, as animal models of Alzheimer's and people with the disease are very different," he said.
The researchers concurred that more research is needed to find out, among other things, what the optimal "dosage" of electromagnetic waves would be -- the 918 megaHerz in US mobile phones, 800 megaHerz in European phones, or another frequency -- and how long "treatment" would have to be given before benefits are seen.
"If we can determine the best set of electromagnetic parameters to effectively prevent beta-amyloid aggregation and remove pre-existing beta amyloid deposits from the brain, this technology could be quickly translated to human benefit against Alzheimer's disease," said USF professor Chuanhai Cao.
But, warned the Alzheimer's Association, just because something works in mice with Alzheimer's, doesn't mean it will work in humans.
"Therapies that have been 'successful' in mouse models of Alzheimer's have not worked in people," Thies said.
The potential new, non-invasive and drug-free therapy could also be used to treat one of the invisible injuries suffered by soldiers in war, Cao said.
"Since production and aggregation of beta-amyloid occurs in traumatic brain injury, particularly in soldiers during war, the therapeutic impact of our findings may extend beyond Alzheimer's disease," he said.
Alzheimer's Disease International, which groups Alzheimer associations around the world, has predicted that around 36 million people will be living with dementia this year.
Pentagon officials have said that up to 360,000 US veterans of Iraq and Afghanistan may have suffered brain injuries.