You already knew this, but the BBC Science Desk reiterates that caffeine really is brain food:
“Caffeine appears to block several of the disruptive effects of cholesterol that make the blood-brain barrier leaky,” said Dr Jonathan Geiger, who led the study.
“High levels of cholesterol are a risk factor for Alzheimer’s disease, perhaps by compromising the protective nature of the blood brain barrier.
“Caffeine is a safe and readily available drug and its ability to stabilise the blood brain barrier means it could have an important part to play in therapies against neurological disorders.”
A spokesman for the Alzheimer’s Society said that the barrier seemed to work less efficiently in people who went on to develop Alzheimer’s or suffer strokes, and the cholesterol link might explain this.