The mice were exposed to cellphone signals from a centrally located antenna. (Eric Younghans, USF Health Communications)

Mice exposed to cellphone radiation seem to gain protection from the memory-robbing effects of Alzheimer's disease, according to a study published this week.

Lead author Gary Arendash of the University of South Florida and his colleagues said they were expecting cellphone exposure to increase the effects of dementia, but that's not what they found.

"It surprised us to find that cellphone exposure, begun in early adulthood, protects the memory of mice otherwise destined to develop Alzheimer's symptoms," Arendash said in a release.

"It was even more astonishing that the electromagnetic waves generated by cellphones actually reversed memory impairment in old Alzheimer's mice."

The study, published Wednesday in the Journal of Alzheimer's Disease, looked at 96 mice, most of which had been genetically modified to develop beta-amyloid plaques in their brains, a marker of Alzheimer's disease. Other mice were not genetically predisposed to Alzheimer's, so the researchers could also test the effects of electromagnetic waves on normal memory.

All of the mice were exposed to the electromagnetic field generated by standard cellphone use for two hour-long periods each day for seven to nine months.

The mice weren't wearing tiny headsets, but their cages were arranged around an antenna that generated the cellphone signal. Each animal was housed the same distance from the antenna, and was exposed to electromagnetic waves like those emitted by a mobile phone pressed against a human head.

Plaque erased

At the end of the experiment, cellphone exposure appeared to erase the build-up of beta-amyloid plaque, and the mice with Alzheimer's performed as well on tests measuring memory and thinking skills as aged mice without dementia.

When older Alzheimer's mice already showing memory problems were exposed to the electromagnetic waves, their memory impairment disappeared.

There was no evidence of abnormal growth in the brains of the Alzheimer's mice, and all major organs were also normal in post-mortem tests.

It will take time to determine how cellphone radio waves exert beneficial effects on memory, the researchers said, but they concluded that electromagnetic field exposure could be an effective, non-invasive and drug-free way to prevent and treat Alzheimer's disease in humans.

The study's authors noted that previous studies have linked a possible increased risk of Alzheimer's to low-frequency electromagnetic fields like those generated by power and telephone lines. But they say mobile phones emit high-frequency electromagnetic waves that are very different.

'Much more research is needed to find out if there could be any beneficial effects of long-term exposure to electromagnetism, and to guarantee its safety.'—Rebecca Wood of the Alzheimer's Research Trust

The team is testing whether different frequencies and strengths offer faster and stronger cognitive benefits.

"This research has been carried out in mice that mimic some of the symptoms of Alzheimer's in people, so we don’t know if any similar effects will be seen in humans," stated Rebecca Wood, chief executive of the Alzheimer's Research Trust in Cambridge, England.

"Although the researchers hope their findings will translate to people, much more research is needed to find out if there could be any beneficial effects of long-term exposure to electromagnetism, and to guarantee its safety," Wood added. "We don't recommend spending 24 hours a day on a mobile phone — we don’t know the long-term effects, and bills could go through the roof."