People who drink more coffee or caffeine-rich drinks tend to forget things less quickly as they get older, and this might mean caffeine helps slow down memory problems linked to Alzheimer’s.

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.

People who drink a moderate amount of coffee or tea may be less likely to develop dementia later in life — about 18% less likely, according to this claim.

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.

Drinking caffeine doesn’t seem to make you more or less likely to get dementia — people who drink the most caffeine had a tiny bit lower risk, but it’s not enough to be sure it’s real.

Scientists aren’t sure if drinking tea, coffee, or caffeine affects your risk of dementia or Alzheimer’s — the evidence is too weak to say for sure.