Repeated use of cell phones may hasten the onset of Alzheimer's disease, according to a study reported in the journal Environmental Health Perspectives.

Swedish researchers have found that the radiation that cell phones emit damage areas of the brain in rats associated with learning, memory and movement.

"A rat's brain is very much the same as a human's. They have the same blood-brain barrier and neurons," Leif Salford, lead researcher and professor at Lund University in Malmo, told BBC News Online.

In their study, researchers exposed rats to two hours of radiation equivalent to that emitted by cells phones. The researchers found that rats exposed to medium and high levels of radiation had an abundance of dead brain cells.

Salford said exposure to mobile phone radiation could trigger Alzheimer's disease in some people.

"What we are saying is those neurons that are already prone to Alzheimer's disease may be stimulated earlier in life," Salford said. "However, this theory is hypothetical. We do not have evidence yet that the human brain is affected in this way."

Although the finding appears bad for mobile phone users, Salford said no cause exists for alarm just yet as more studies are needed. However, he added that repeated use of mobile phone might not be a good idea in the long term.

Other sources: BBC