For nearly two decades, scientists have believed that brain inflammation contributes to Alzheimer’s disease and dementia—and countless clinical trials have attempted, unsuccessfully, to demonstrate how anti-inflammatory drugs could help. Now, researchers in Germany and the U.S., have discovered that inflammation of the microglia, which are brain cells, is not associated with Alzheimer’s or dementia after all. The team suggests that a loss of microglia is what actually contributes to the brain deterioration. The next step is to find out what causes the microglia to degenerate. That could lead to studies on how to keep these brain cells alive and healthy as a means of staving off brain disease.