Study: Prolonged cell phone use increases brain activity

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Updated: August 4, 2011 4:20PM

A new study suggests that 50 minutes of cell phone exposure increases brain activity — but it doesn’t answer the much-debated question of whether cell phones might be harmful to your health.

Cell phones emit radiofrequency waves similar to those used in microwave ovens but at extremely low levels.

Past studies on whether cell phone use might cause or contribute to brain tumors and other health problems have been inconclusive or found no clear connection.

The new study, being published today in the Journal of the American Medical Association, sought to measure the impact of cell phone radiation on brain glucose metabolism — an indicator of brain activity.

Researchers placed Samsung cell phones over the right and left ears of 47 healthy adults. Then they took PET scans of participants’ brains twice — once after the cell phone in the right ear had been activated with the sound muted for 50 minutes and again after both cell phones had been off for 50 minutes.

They found that cell phone exposure increased the brain’s glucose metabolism by 7 percent in the regions of the brain closest to the phone’s antenna.

But it’s not clear whether that could have long-term health consequences, said lead author Dr. Nora Volkow, director of the National Institute on Drug Abuse.

“What it does tell us that we need to look into this,” Volkow said. “If we had seen nothing, then I think it would have been much easier to say we don’t need to worry about it.”

Dr. Jack Kessler, chairman of neurology at Northwestern University’s Feinberg School of Medicine, cautioned against making too much of the study results, as the increase in brain activity was small “in relationship to the type of things that happen normally when we’re using our brains.”

“Is this a cause for any kind of real concern or alarm? I would say absolutely not,” said Kessler, who was not involved in the study.

“Does this raise a very valid scientific issue of [whether] cell phones exert a measurable effect and should we know more about it? I think yes.”