Cell phone use and the brain: Study

By Dr. Ananya Mandal, MDFeb 22 2011

Experts are still grappling with facts and fiction regarding brain damage caused by cell phone use. Dr. Nora Volkow, who is lead author of a new study published in the Feb. 23 issue of the Journal of the American Medical Association said, “We don’t know whether this is detrimental or whether it could have some potential beneficial effects. We don’t know one way or the other… Studies need to be done to see if there are long-lasting consequences. It’s an important question.” At present the best bet is to use an ear piece or the speaker phone, “particularly in children and adolescents whose brains are much more vulnerable to insults of certain kinds,” said Volkow, who is director of the U.S. National Institute on Drug Abuse. Another alternative is using text messages. “These solutions are so simple, trivial,” said Volkow.

For this study the team involved 47 volunteers who were brought into a lab at the U.S. National Institutes of Health, where they had cell phones positioned at both their left and right ears. Then they measured metabolism of glucose in the brain. This is a measure of how hard the organ is working. They used positron emission tomography (PET) scans. Results showed that metabolism in the orbitofrontal cortex and temporal pole regions of the brain, those closest to the antenna, was about 7 percent higher when the right phone was in the “on” position than when both phones were off. The brain activity decreased with distance from the antenna. However Volkow added, “That [level of brain activity] is what we see normally when viewing a movie.”

“There are many questions that are now raised from this very, very important study,” says Lennart Hardell, a cancer researcher at University Hospital in Orebro, Sweden, and the co-author of an editorial accompanying the study. “What about long-term use, and what about children and young persons?”

Dr. Giuseppe Esposito, chief of nuclear medicine at Georgetown University Hospital and an associate professor of radiology at Georgetown University Medical Center in Washington, D.C. said, “It is not real world…Obviously, this is not what you do normally… I don't think we can draw any conclusions as to the health effects of cell phones in general or radiofrequency simulations from this study.” Volkow said no one yet knows whether “exposure to these external sources, two to three hours a day for five to 10 years [is going to result] in any untoward effects. And if you get exposed very early on when the brain is very plastic, would there be any detrimental effects? That’s an important question that needs to be addressed.”

The team is now planning a retrospective study to see if long-time cell phone users of around two hours a day over 10 years have any obvious health consequences.

John Walls, vice president of public affairs for CTIA-The Wireless Association said, “Since we are not a scientific organization, with respect to the matter of health effects associated with wireless base stations and the use of wireless devices, CTIA and the wireless industry have always been guided by science, and the views of impartial health organizations. The peer-reviewed scientific evidence has overwhelmingly indicated that wireless devices, within the limits established by the [U.S. Federal Communications Commission], do not pose a public health risk or cause any adverse health effects.”