Cell phone use may have effect on brain activity, but health consequences unknown

Feb 22, 2011

In a preliminary study, researchers found that 50-minute cell phone use was associated with increased brain glucose metabolism (a marker of brain activity) in the region closest to the phone antenna, but the finding is of unknown clinical significance, according to a study in the February 23 issue of JAMA.

"The dramatic worldwide increase in use of cellular telephones has prompted concerns regarding potential harmful effects of exposure to radiofrequency-modulated electromagnetic fields (RF-EMFs). Of particular concern has been the potential carcinogenic effects from the RF-EMF emissions of cell phones. However, epidemiologic studies of the association between cell phone use and prevalence of have been inconsistent (some, but not all, studies showed increased risk), and the issue remains unresolved," according to background information in the article. The authors add that studies performed in humans to investigate the effects of RF-EMF exposures from cell phones have yielded variable results, highlighting the need for studies to document whether RF-EMFs from cell phone use affects brain function in humans.

Nora D. Volkow, M.D., of the National Institutes of Health, Bethesda, Md., and colleagues conducted a study to assess if cell phone exposure affected regional activity in the human brain. The randomized study, conducted between January 1 and December 31, 2009, included 47 participants. Cell phones were placed on the left and right ears and brain imaging was performed with positron (PET) with (18F)fluorodeoxyglucose injection, used to measure brain twice, once with the right cell phone activated (sound muted) for 50 minutes ("on" condition) and once with both cell phones deactivated ("off" condition). Analysis was conducted to verify the association of metabolism and estimated amplitude of radiofrequency-modulated emitted by the cell phone. The PET scans were compared to assess the effect of cell phone use on brain glucose metabolism.

The researchers found that whole-brain metabolism did not differ between the on and off conditions. However, there were significant regional effects. Metabolism in the brain region closest to the antenna (orbitofrontal cortex and temporal pole) was significantly higher (approximately 7 percent) for cell phone on than for cell phone off conditions. "The increases were significantly correlated with the estimated electromagnetic field amplitudes both for absolute metabolism and normalized metabolism," the authors write. "This indicates that the regions expected to have the greater absorption of RF-EMFs from the cell phone exposure were the ones that showed the larger increases in glucose metabolism."

"These results provide evidence that the human brain is sensitive to the effects of RF-EMFs from acute cell phone exposures," the researchers write. They add that the mechanisms by which RF-EMFs could affect brain glucose metabolism are unclear.

"Concern has been raised by the possibility that RF-EMFs emitted by cell phones may induce brain cancer. … Results of this study provide evidence that acute cell phone exposure affects brain metabolic activity. However, these results provide no information as to their relevance regarding potential (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," the authors conclude.

The results of this study add information about the possible effects of radiofrequency emissions from wireless phones on , write Henry Lai, Ph.D., of the University of Washington, Seattle, and Lennart Hardell, M.D., Ph.D., of University Hospital, Orebro, Sweden, in an accompanying editorial.

"Although the biological significance, if any, of increased glucose metabolism from acute cell phone exposure is unknown, the results warrant further investigation. An important question is whether glucose metabolism in the brain would be chronically increased from regular use of a wireless phone with higher radiofrequency energy than those used in the current study. Potential acute and chronic health effects need to be clarified. Much has to be done to further investigate and understand these effects."

The editorial authors also question whether the findings of Volkow et al may be a marker of other alterations in from radiofrequency emissions, such as neurotransmitter and neurochemical activities? "If so, this might have effects on other organs, leading to unwanted physiological responses. Further studies on biomarkers of functional changes from exposure to radiofrequency radiation are definitely warranted."

Explore further: Researchers find unsuspected characteristics of new CF drugs, offering potential paths to more effective therapies

More information: JAMA. 2011;305[8]808-814.

Related Stories

Study finds mobiles excite brain cells

Jun 27, 2006

We know cell phones affect the brain. But the question of whether the electromagnetic fields emitted by mobile handsets that excite brain cells actually do any harm remains unanswered, however, by researchers ...

WHO study suggests link between cell phones and tumors

Oct 27, 2009

(PhysOrg.com) -- Preliminary results of an International investigation by the World Health Organization (WHO) suggest there may be a "significantly increased risk" of some types of brain tumors after use of ...

Cell phone may hurt child's health

Oct 09, 2007

Professor Kjell Mild of Sweden's Orbero University said young children are more at risk when using cell phones because of their thinner skulls.

Recommended for you

Strategy proposed for preventing diseases of aging

9 hours ago

Medicine focuses almost entirely on fighting chronic diseases in a piecemeal fashion as symptoms develop. Instead, more efforts should be directed to promoting interventions that have the potential to prevent ...

User comments : 2

Adjust slider to filter visible comments by rank

Display comments: newest first

gwrede
1 / 5 (1) Feb 22, 2011
So, call me an idiot.....

I read the headline, and decided that the 99 articles I've seen posted on PhysOrg, pro, and the 1 articles I've seen against, should give me a Qualified Bias.

Too bad these figures don't even start to influence the people they really should.

Today, if I were born in the US, I'd either move abroad, or I'd commit something my parents would not appreciate.
SkiSci
not rated yet Feb 22, 2011
ill just texted my brain to death instead