A study published in JAMA Feb 23, 2011 led by Nora D. Volkow et al, Director of the National Institute on Drug Abuse of the National Institutes of Health, shows a 50-minute cell phone exposure was associated with increased brain glucose metabolism in the region closest to the antenna. According to Microwave News, while it is not clear if the short-term changes will lead to health consequences, Volkow already has preliminary indication of long-term effects. The finding that cell phone radiation speeds up glucose metabolism, a marker of brain activity, at non-thermal levels of microwave exposure, is expected to profoundly change the discussion about cell phone health risks.

Concern has been raised that if cell phone radiation is impacting glucose levels, is it also impacting neurotransmitters and neurochemical activities? Further studies are urgently needed.

While much focus has been placed on the risk of brain tumors from cell phones, this study, which was statistically significant, confirms important neurological impact.  It comes a week after scientists at Cal Tech confirmed that very weak varying electric fields in brain tissue significantly affect neuronal behavior.

Cell Phone Radiofrequency Radiation Exposure and Brain Glucose Metabolism JAMA. 2011;305(8):828-829

ABSTRACT:

Nora D. Volkow, Dardo Tomasi, Gene-Jack Wang, Paul Vaska, Joanna S. Fowler, Frank Telang, Dave Alexoff, Jean Logan, Christopher Wong. Effects of Cell Phone Radiofrequency Signal Exposure on Brain Glucose Metabolism. JAMA. 2011;305(8):808-813.

Author Affiliations: National Institute on Drug Abuse, Bethesda, Maryland (Dr Volkow); National Institute on Alcohol Abuse and Alcoholism, Bethesda (Drs Volkow, Tomasi, and Telang and Mr Wong); and Medical Department, Brookhaven National Laboratory, Upton, New York (Drs Wang, Vaska, Fowler, and Logan and Mr Alexoff).

Abstract

Context The dramatic increase in use of cellular telephones has generated concern about possible negative effects of radiofrequency signals delivered to the brain. However, whether acute cell phone exposure affects the human brain is unclear.

Objective To evaluate if acute cell phone exposure affects brain glucose metabolism, a marker of brain activity.

Design, Setting, and Participants Randomized crossover study conducted between January 1 and December 31, 2009, at a single US laboratory among 47 healthy participants recruited from the community. Cell phones were placed on the left and right ears and positron emission tomography with (¹⁸F)fluorodeoxyglucose injection was used to measure brain glucose metabolism twice, once with the right cell phone activated (sound muted) for 50 minutes (“on” condition) and once with both cell phones deactivated (“off” condition). Statistical parametric mapping was used to compare metabolism between on and off conditions using paired t tests, and Pearson linear correlations were used to verify the association of metabolism and estimated amplitude of radiofrequency-modulated electromagnetic waves emitted by the cell phone. Clusters with at least 1000 voxels (volume >8 cm³) and P < .05 (corrected for multiple comparisons) were considered significant.

Main Outcome Measure Brain glucose metabolism computed as absolute metabolism ( mol/100 g per minute) and as normalized metabolism (region/whole brain).

Results Whole-brain metabolism did not differ between on and off conditions. In contrast, metabolism in the region closest to the antenna (orbitofrontal cortex and temporal pole) was significantly higher for on than off conditions (35.7 vs 33.3 mol/100 g per minute; mean difference, 2.4 [95% confidence interval, 0.67-4.2]; P = .004). The increases were significantly correlated with the estimated electromagnetic field amplitudes both for absolute metabolism (R = 0.95, P < .001) and normalized metabolism (R = 0.89; P < .001).

Conclusions 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.

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Commentary by Dr. Joel Moskowitz, ConsumerReports.org, Mar 9, 2011

Your editor requested my expert feedback on this study. Here are the comments I sent him.

This study conducted by Dr. Volkow and her colleagues is significant in many regards. The study employed a strong research design. It demonstrates that the radiation emitted by a typical cell phone in a 50-minute phone call creates functional changes in one’s brain. Moreover, the changes were found exactly where predicted. They were greatest in the areas of the brain nearest the antenna and diminished substantially further away from the antenna.

The telecommunications industry argues that government health agencies and the scientific community in the U.S. believe that cell phone radiation is not biologically reactive despite the fact that many published studies have shown evidence to the contrary. It will be hard for the industry to dismiss the current study which was conducted at a national research laboratory by the director of one of the National Institutes of Health. Moreover, this study was published in one of the leading medical journals.

Although this study focused on the short term effects of cell phone radiation, our Center’s published research review* which examined long term studies found that cell phone use over a 10-year period increased one’s risk of tumors, especially tumors of the brain, the salivary gland, and a nerve linking the ear to the brain. Thus, long-term studies provide evidence of serious health consequences. Moreover, there are now at least eight short-term studies that find cell phone radiation damages human sperm.

The FDA’s longstanding comment that the “weight of scientific evidence has not linked cell phones with any health problems” is misleading. If one weights all of the evidence equally one might come to this conclusion because most studies have been industry funded, and these studies tend to be weaker in terms of research quality. Our review* of the epidemiologic research and Henry Lai’s review of the biologic research found that non-industry-funded studies more often than not find harmful health effects whereas industry-funded research does not. The FCC, the FDA, and the NCI seem to be protecting the telecommunications industry by focusing on “the weight of the evidence” argument ignoring the fact that some of the evidence is of considerably higher quality than the rest.

Although the current study does not shed light on what mechanisms caused the observed changes in brain function, the authors are confident the changes they observed are not due to the heat generated by cell phone radiation. This is extremely important because all cell phones sold in the U.S. must pass a safety test based on their heating potential as the Federal government assumes the only way the phones can harm you is through heat. The current study demonstrates that a phone with a specific absorption rate (or SAR) of 0.9 watts per kilogram, which is considerably less than the legal limit of 1.6 watts per kilogram, increases the user’s brain activity near the phone’s antenna. The Federal safety standards which were established in 1996 do not appear to be an adequate guarantee that our cell phones are safe. These regulations need to be reviewed in light of current research.

Many cell phones have a manufacturer’s warning in the manual, but how many consumers read or pay attention to these warnings? One such warning states, “Use hands-free operation if it is available and keep the ___ device at least 0.98 in. (25 mm) from your body (including the abdomen of pregnant women and the lower abdomen of teenagers) when the ___ device is turned on and connected to the wireless network.”

The results of the current study support an important precautionary health warning many foreign governments have adopted — keep your cell phone away from your body whenever it is on. Use a wired headset, text or speaker phone and don’t carry the phone in your pocket. Children and adolescents are particularly vulnerable and their use of cell phones should be limited.

Given how common cell phones are in our society, we need to launch a major research program to study the effects of cell phone radiation and how to minimize harm. This research could be funded by levying a small fee on every cell phone. A one dollar fee per phone would generate more than $250 million per year to fund research and education in the U.S.

Joel M. Moskowitz, Ph.D., Director
Center for Family and Community Health
School of Public Health
University of California, Berkeley

* Myung SK, Ju W, McDonnell DD, Lee YJ, Kazinets G, Cheng CT, Moskowitz JM. Mobile phone use and risk of tumors: a meta-analysis. Journal of Clinical Oncology. 2009 Nov 20; 27(33):5565-5572. Epub 2009 Oct 13.

Abstract

PURPOSE: Case-control studies have reported inconsistent findings regarding the association between mobile phone use and tumor risk. We investigated these associations using a meta-analysis. METHODS: We searched MEDLINE (PubMed), EMBASE, and the Cochrane Library in August 2008. Two evaluators independently reviewed and selected articles based on predetermined selection criteria. RESULTS: Of 465 articles meeting our initial criteria, 23 case-control studies, which involved 37,916 participants (12,344 patient cases and 25,572 controls), were included in the final analyses. Compared with never or rarely having used a mobile phone, the odds ratio for overall use was 0.98 for malignant and benign tumors (95% CI, 0.89 to 1.07) in a random-effects meta-analysis of all 23 studies. However, a significant positive association (harmful effect) was observed in a random-effects meta-analysis of eight studies using blinding, whereas a significant negative association (protective effect) was observed in a fixed-effects meta-analysis of 15 studies not using blinding. Mobile phone use of 10 years or longer was associated with a risk of tumors in 13 studies reporting this association (odds ratio = 1.18; 95% CI, 1.04 to 1.34). Further, these findings were also observed in the subgroup analyses by methodologic quality of study. Blinding and methodologic quality of study were strongly associated with the research group. CONCLUSION: The current study found that there is possible evidence linking mobile phone use to an increased risk of tumors from a meta-analysis of low-biased case-control studies. Prospective cohort studies providing a higher level of evidence are needed.

http://www.ncbi.nlm.nih.gov/pubmed/19826127

http://blogs.consumerreports.org/electronics/2011/02/study-shows-cell-phone-radiation-can-alter-brain-function.html