Giving mice caffeine over time, plus a little extra right before exposing them to a brain-toxic protein, helps them remember better and make smarter choices in simple tests.

In mice, a special drug called SCH58261, given daily for four days, works just as well as coffee to protect the brain from memory problems caused by a harmful protein.

People who drink a lot of coffee or tea—more than 300 mg of caffeine a day—might see their memory problems from Alzheimer’s slow down more than people who drink very little caffeine, based on studies that track groups over time.

Caffeine blocks a brain chemical called adenosine, and this might help reduce the buildup of sticky clumps in the brain that are linked to Alzheimer’s.

People who drink a lot of coffee or consume a lot of caffeine seem to have better memory and slower brain decline as they age, according to studies that watch people over time — so coffee might help keep your brain sharp without costing much.

Even when there’s a lot more caffeine than the sticky brain proteins involved in Alzheimer’s, caffeine doesn’t stop those proteins from clumping together — so something else in coffee must be doing the real work.