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.

Even when there’s a lot more caffeine than the sticky proteins in the brain, it doesn’t stop those proteins from clumping together — so caffeine probably isn’t the main reason coffee might help prevent brain clumps.

Even without caffeine, dark roast coffee can still stop harmful clumps in the brain from forming—so it’s not the caffeine doing the job, but other chemicals created when the coffee is roasted.

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.

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.

Dark roast coffee seems to stop harmful clumps in the brain better than light roast coffee, and scientists think it’s because the darker roasting makes more of a special compound called phenylindane.