Mobile phones linked to increased brain activity

RESEARCHERS say they have found a connection between mobile phone use and increased brain activity.

American scientists found that 50 minutes of mobile phone use was associated with increased “brain glucose metabolism” — a marker of brain activity — in the region closest to the phone antenna.

Health implications are unknown, they say in the Journal of the American Medical Association.

The article points to concerns regarding potential harmful effects of exposure to radiofrequency-modulated electromagnetic fields (RF-EMFs) of mobile phones.

But studies of the association between mobile phone use and prevalence of brain tumours have been inconsistent and remain unresolved, they say.

Nora D Volkow, of the National Institutes of Health in Bethesda, Maryland, and colleagues conducted a study involving 47 people.

Mobile phones were placed on the left and right ears and brain imaging was performed to measure brain glucose metabolism twice, once with the right phone activated — but with the sound muted — for 50 minutes and once with both phones deactivated.

The researchers found whole-brain meta-bolism did not differ between the on and off conditions — but there were significant “regional” effects.

Metabolism in the brain area closest to the antenna (orbitofrontal cortex and temporal pole) was significantly higher (approximately 7%) for “mobile phone on” than “mobile phone off” conditions.

The researchers write: “Results of this study provide evidence that acute cell (mobile) phone exposure affects brain metabolic activity.

“However, these results provide no information as to their relevance regarding potential carcinogenic effects (or lack of such effects) from chronic cell phone use.

“Further studies are needed to assess if these effects could have potential long-term harmful consequences.”

Reacting to the study, Professor Patrick Haggard, of the Institute of Cognitive Neuroscience at University College London, said: “This study reports a 7% increase in brain metabolism close to the antenna of a commercial mobile phone during transmission, compared to when the phone is off.

“It is not the first study to report such effects, but it is considerably larger than any of the previous studies, including many more participants. “This is a very interesting result, since it suggests a possible direct effect of mobile phone signals on brain function. However, the result should be treated with some caution. “However, if further studies confirm that mobile phone signals do have direct effects on brain metabolism, then it will be important to investigate whether such effects have implications for health,” he said.