Cell phones may lead to stimulation of parts of brain - Speculation on cancer continues

By Dr. Ananya Mandal, MDFeb 23 2011

There is still debate as to whether cell phones damage the brain. The cell phone industry, along with nearly all major national and international medical associations have always responded with the same answer that there is no evidence that cell phone radiation can even affect the brain, let alone cause cancer.

A new study reported in the Feb. 23 Journal of the American Medical Association says at least one of those arguments may be put to rest. Dr. Nora Volkow, director of the National Institute on Drug Abuse, found that a cell phone’s electromagnetic field can indeed cause changes in brain activity, with the regions closest to the antenna showing higher rates of energy consumption.

This is important since 217 million Americans, about 71 percent of the country’s population have a cell phone.

This study conducted on 47 people during a 50-minute call, has garnered some interesting results on brain activity. The researchers used PET (positron emission tomography) scan to measure brain activity, known as glucose metabolism, they found that when the phone was in the ‘on’ position, they actually found increase in activity, shown on the PET scan in red. During one scan, a cell phone connected to a muted call was attached to participants' right ear; during the other, they were phone-free. When the phone was turned on, participants experienced a 7 percent increase in the rate of glucose metabolism. Co-anchor Erica Hill asked, “But what’s the significance of that increase in (brain) activity?” Dr. Nora Volkow said, “Because there’s been such a massive expansion in cellphone use these past 15 to 20 years, it behooves us to try to understand whether, if we use these devices repeatedly and intensively for years, do they have lasting effects?” Those effects could vary widely depending upon the location of a cellphone's antenna, the frequency on which it operates, and how long one uses the device, Volkow said.

Dr. Keith L. Black, chairman of neurosurgery at Cedars-Sinai Medical Center in Los Angeles, who was not involved in the study said, “It’s a surprising finding… We normally don’t expect the brain to be activated unless it’s in response to stimulation, or unless it’s in a pathological state such as epilepsy.” Black added. “We don’t know whether this is a good effect, a neutral effect or a bad effect — and if it is a bad effect, we don’t know what kind of exposure is required” to cause harm, he said. That should come with further research.

In an editorial accompanying the study, University of Washington bioengineer Henry Lai and Swedish oncologist Lennart Hardell wrote that the study raises questions that are potentially worrisome.