People who have their cell phones next to their ear for fifty minutes experience a 7% increase in sugar consumption in part of the brain closest to the phone's antenna, researchers from the National Institutes of Health, USA revealed in an article published in JAMA (Journal of the American Medical Association).
The sizeable increase in cell phone use has concerned many lay people as well as health care professionals about potential harmful effects from radio frequency signals that reach the brain, the authors wrote. However, nobody really knows whether whatever effect there might be is negative.
The scientists set out to find out whether acute cell phone exposure might affect glucose metabolism in the brain - the rate at which the brain consumes sugar. This is a marker of brain activity.
They carried out a randomized, crossover study with 47 healthy volunteers recruited from the community. More specifically, they were measuring the effects magnetic fields (RF-EMFs) that come from the telephone's antenna might have on brain activity. It was conducted at a US laboratory between January 1st and December 1st, 2009.
The participants had cell phones placed on their right and left ears. Positron emission tomography with fluorodeoxyglucose injection were used to gauge brain sugar metabolism twice. Brain activity was measured the first time with phones on both ears, sound muted for 50 minutes (but cell phone was "on"), and again with both cell phones switched off.
They found that on the side of the brain next to the cell phone that was switched on, brain sugar activity was 7% higher after fifty minutes - the brain was using up glucose at a higher rate.
The authors concluded:
"In healthy participants and compared with no exposure, 50-minute cell phone exposure was associated with increased brain glucose metabolism in the region closest to the antenna. This finding is of unknown clinical significance."
"Effects of Cell Phone Radiofrequency Signal Exposure on Brain Glucose Metabolism"
Nora D. Volkow, MD; Dardo Tomasi, PhD; Gene-Jack Wang, MD; Paul Vaska, PhD; Joanna S. Fowler, PhD; Frank Telang, MD; Dave Alexoff, BSE; Jean Logan, PhD; Christopher Wong, MS
JAMA. 2011;305(8):808-813. doi: 10.1001/jama.2011.186
Another study carried out by scientists from the University of Manchester, England, found that radio frequency exposure from cell phones does not seem to raise the risk of brain cancers in any significant amount. They used publically available data from the UK Office of National Statistics and examined trends in new brain cancer diagnoses in England between 1998 and 2007. The study was published in Bioelectomagnetics.
Written by Christian Nordqvist