Hold that cell phone close to your head, and your brain could get about 7 percent more active. That’s the finding of a new study published this month in the Journal of the American Medical Association.

It’s unclear, however, what this new finding means for your health.

First, here’s what the study found. According to Wired, A team led by neuroscientist Nora Volkow of the National Institutes of Health attached a pair of cell phones — one turned off, the other with a live call — to each experimentee’s head. “Twenty minutes into the call, clinicians injected a radioactive form of sugar into each person, then began imaging their brains with a Positron Emission Topography machine. Over the course of 30 minutes, the sugar pooled in the brain’s most active regions and revealed the energy use to the brain scanner.”

The result? “Accounting for normal activity, the subjects showed about a 7 percent boost in sugar use on the side of the head where the active cellphone was.”

What that boost means, though, is unclear. “The preliminary study … raises many more questions than it answers,” reports LA Times. “But by providing solid evidence that cellphone use has measurable effects on brain activity, it suggests that the nation’s passionate attachment to its 300 million cellphones may be altering the way we think and behave in subtle ways.” NY Times reports on one potential concern:

Although speculative, one theory about how an artificial increase in brain glucose metabolism could be harmful is that it could potentially lead to the creation of molecules called free radicals, which in excess can damage healthy cells. Or it may be that repeated stimulation by electromagnetic radiation could set off an inflammatory response, which studies suggest is associated with a number of heath problems, including cancer.
[Lennart Hardell, a cancer researcher at University Hospital in Orebro], who has previously suggested a link between cell phone use and brain cancer, says the finding doesn’t necessarily strengthen his case, because there’s no direct link between increased brain metabolism and cancer. But he says it’s still possible researchers will find an indirect one, perhaps involving hormonal changes or the production of molecules known as free radicals in the brain.
What can you do in the meantime to keep your cellphone use as safe as possible? “Just use a wired headset or the speakerphone function,” is what Volkow told Wired. “That keeps the phone far enough away to make it an insignificant risk.” For more tips on reducing cell phone radiation, read about safer cell phone practices and buying guidelines.