Study: Don t let cell phones go to your head

Cellular phones may increase brain activity in regions closest to the antenna, according to a study published in the February 23 issue of the Journal of the American Medical Association. Researchers affiliated with The National Institute on Drug Abuse and housed within the National Institutes of Health (NIH), conducted brain PET (positron emission tomography) scans on 47 participants to measure their oxygen utilization, a reflection of glucose metabolism. The test subjects held one cell phone to each ear for 50 minutes while two PET scans were performed — one when the phone against the right ear was turned on and muted but the other phone was off, and the second when both phones were turned off. The researchers found that the regions of the brain closest to the antenna — the orbitofrontal cortex and temporal lobe — exhibited a statistically significant increase in glucose metabolism when the phone was turned on.

While some media reports aggrandized this finding to support the notion that cellphones cause cancer, there is no data behind that fear. In fact, according to the Interphone study, a large epidemiological study published in the International Journal of Epidemiology in May 2010, cell phone use actually had a 10-to-25 percent protective effect against glioma and meningioma brain tumors among those who used the devices at a moderate rate. However, among people who used cell phones the most and the longest — for at least 10 years and on average 30 minutes or more per day — the risk of glioma may have been marginally elevated compared to non-cell phone users.

Left wondering about the biological plausibility of increased brain metabolism leading to cancer, ACSH's Dr. Gilbert Ross points out that the electromagnetic radiation emitted from cell phones is too weak to produce the breaking of the chemical bonds (mutations) often linked to cancer causation. “Several large studies have shown that heavy cell phone use for long durations may be weakly associated with a slight risk of acoustic neuromas — slow benign growths near the brain on the eighth cranial nerve — but I find the evidence far from compelling about linkage to malignant brain tumors.

ACSH's Dr. Josh Bloom remarks, “It isn’t impossible that the heat produced by the phone might increase metabolic activity in certain regions of the brain, but there’s a quantum leap from saying that to suggesting a connection between phones and cancer.”