A new study in the Journal of American Medical Association does not find a link between cell phone exposure and brain cancer. It also doesn't prove that the two are in no way correlated. What the researchers did discover, however, is that long cell phone calls result in increased brain activity.

What, exactly, does this mean? Well, "brain activity means that the cells are using glucose to create energy," explains CNN's Danielle Dellorto. "The brain normally produces the amount of glucose it needs to function properly. But these new findings don't tell us whether activating the cells artificially, in this case by cell phone radiation, will have a negative effect on health."

Researchers examined the brain activity of the study's participants in two situations: once after using the phone for 50 minutes, and once after simply holding the phone--in the off position--against their heads for the same period of time. "Compared with subjects whose phones were turned off, the group whose phones were on had 'significantly higher' brain activity in the area closest to the telephone antenna," Dellorto reports.

According to Kristina Fiore at Med Page Today, "the effects on neural activity could be due to changes in neurotransmitter release, cell membrane permeability, cell excitability, or calcium efflux." The researchers also noted the theory that "heat from cell phones can contribute to functional brain changes, but that is probably less likely to be the case."

Experts urge that further study is needed, before any conclusions as to the effect of cell phones can be made. In the mean time, Dellorto offers, "consumers can take steps to limit cell phone radiation exposure by using the speakerphone or a wired earpiece to make calls."