Despite long-standing concerns about the health effects of cellphones, a new study suggests that radiation from the devices may actually have a beneficial effect when it comes to Alzheimer’s disease. Specifically, long-term exposure to the electromagnetic waves associated with cellphone use may actually protect against — and even reverse — Alzheimer’s, according to a study led by University of South Florida researchers at the Florida Alzheimer’s Disease Research Center and published Wednesday in the Journal of Alzheimer’s Disease.