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.

Caffeine helps protect brain cells from a harmful protein linked to Alzheimer’s, and scientists think it’s because of a specific part of caffeine’s action—other similar drugs that block the same part also work, but ones that block a different part don’t.

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.

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.

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.