Your Brain on Cellphones: Effects Present, Consequences Unknown
Feb 24, 2011 11:28 AM PT
An issue that periodically makes its way into public discourse -- the impact and possible dangers to brain development and health posed by the ubiquitous use of cellphones -- is being revisited thanks to a newly published scientific study in The Journal of the American Medical Association.
However, rather than offering any definitive answers, the new research, led by Nora D. Volkow of the National Institutes of Health, raises more questions. Volkow and colleagues found that 50 minutes of cellphone use was associated with increased brain glucose metabolism -- a marker of brain activity -- in the region closest to the phone antenna. What that means is unclear.
The research team was not unaware of the health controversies surrounding cellular telephones, particularly concerns that exposure to the devices' radiofrequency-modulated electromagnetic fields could potentially have carcinogenic effects.
Epidemiologic studies of the association between cellphone use and the prevalence of brain tumors have been inconsistent, they pointed out in their report, with some, but not all, showing increased risk. That issue, in short, is unresolved.
Regional Metabolic Effects
The point of this study, however, which was conducted at the end of 2009, was to assess whether cellphone exposure affected regional activity in the human brain. Cellphones were placed on the left and right ears of 47 participants, and brain imaging using positron emission tomography with (18F) fluorodeoxyglucose injection -- used to measure brain glucose metabolism -- was performed twice.
The first scan was done with the right cellphone activated and the sound muted for 50 minutes -- that is, in the "on" condition -- and the second was done with both cellphones deactivated, that is, in the "off" condition. The scans were then compared to assess the effect of cellphone use on brain glucose metabolism.
Whole-brain metabolism did not differ in the on and off conditions. However, there were significant regional effects, according to the study authors. Metabolism in the brain region closest to the antenna -- the orbitofrontal cortex and temporal pole -- was significantly higher, approximately 7 percent, when the cellphone was on versus when it was off.
"These results provide evidence that the human brain is sensitive to the effects of RF-EMFs from acute cellphone exposures," the researchers state in their report. "However, these results provide no information as to their relevance regarding potential carcinogenic effects (or lack of such effects) from chronic cellphone use."
Neither the study authors nor JAMA responded to TechNewsWorld's requests to comment for this story by press time.
While the short-term results of cellphone usage may be safe, it is the long term that concerns Devra Lee Davis, PhD MPH, president and founder of Environmental Health Trust, and author of Disconnect: The Truth About Cell Phone Radiation, What the Industry Has Done to Hide It, and How to Protect Your Family.
"Glucose is the main fuel of the brain," Davis told TechNewsWorld.
Essentially, the study found that in the areas the cellphone signal reached, there was an increase in glucose. In other words, the cellphone radiation affected the brain.
Possibly for a healthy adult, the effect wouldn't matter, but patients with brain health issues like Parkinson's or veterans with brain injuries should be very careful of such phone use, Davis said, as should children and teenagers, whose skulls are still thin and developing.
"Most people are clueless about how cellphones work," she said. "Basically, they are two-way microwave radios that use the same frequencies as a microwave oven. You can boil water in a microwave in two minutes."
More study is necessary for the complete ramifications of cellphone use to become clear, added Davis.
Meanwhile, people should take precautions, starting with healthy living habits including sleeping in the dark and using headsets instead of holding devices next to the body, she suggested.
Cellphones should be kept away from the body in general, Davis advised. "It won't help much to use headphones if you keep the phone in your pocket."