Brain scans show cellphones boosting brain metabolism

Spending 50 minutes with a cellphone by your ear might increase brain activity in the area closest to the antenna. But concerns about brain cancer are still unsettled.
Written by Janet Fang, Contributor

Hmm. Looks like cellphones make our brains burn more sugary energy.

A 50-minute call might boost brain activity in the area closest to the phone antenna – making the brain burn 7% more energy, a new study shows.

“We have no idea what this means yet or how it works,” says study author Nora Volkow of the National Institutes of Health. “But this is the first reliable study showing the brain is activated by exposure to cellphone radio frequencies.”

About 5 billion cellphones are in use around the world right now. Studies of the association between cellphone use and brain tumors have been inconsistent. Some, but not all, studies showed increased risk, but even these can’t say that cellphone use causes cancer. All in all, the issue remains unresolved.

So Volkow and colleagues looked at how exposure to cellphone radiation – or radiofrequency-modulated electromagnetic fields (RF-EMFs) – affected regional activity in the brains of 47 participants.

  1. First, they placed cellphones on both the left and right ears (Samsung flip phones with an embedded antenna).
  2. They were injected with radioactive glucose (sugar), which is used to measure brain glucose metabolism (a marker of brain activity).
  3. Then they had their brains scanned by positron emission tomography (PET). As the sugar pooled in the brain’s most active regions, the scanner picked up on the energy use. This happened twice:
  4. Once with the right cellphone on, but muted, for 50 minutes.
  5. Then again with both cellphones off.

They found that whole-brain metabolism wasn’t different between the on and off conditions. However, the brain region closest to the antenna consumed more glucose when the phone was on. Metabolism in that area was 7% higher while the phone was on than when it was off.

That’s several times less activity than visual brain regions show during an engaging movie, says coauthor Dardo Tomasi of Brookhaven National Laboratory. “The effect is very small, but it’s still unnatural. Nature didn’t prepare our brains for this.”

Though they don’t know what the mechanisms actually are, and these results provide no information relevant to carcinogenic effects (or lack of) on the brain.

Or could they... ? Michael Kundi of the Medical University of Vienna says: “Since a brain tumor utilizes excessive amounts of glucose, changes in glucose utilization may be a key mechanism to support tumor growth."

Volkow conludes that, while the longterm consequences are unclear, it’s cheap and worthwhile to take matters into your own hands. “You don’t have to wait around on us for the answers. Just use a wired headset or the speakerphone function,” she says. “That keeps the phone far enough away to make it an insignificant risk.”

The study appeared in Journal of the American Medical Association this week.

Image by dennoir via Flickr

This post was originally published on Smartplanet.com

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