Coffee may cut the risk of dementia by blocking the damage cholesterol can inflict on the body, research suggests.

The drink has already been linked to a lower risk of Alzheimer's Disease, and a study by a US team for the Journal of Neuroinflammation may explain why.

A vital barrier between the brain and the main blood supply of rabbits fed a fat-rich diet was protected in those given a caffeine supplement.

UK experts said it was the "best evidence yet" of coffee's benefits.

The "blood brain barrier" is a filter which protects the central nervous system from potentially harmful chemicals carried around in the rest of the bloodstream.

Other studies have shown that high levels of cholesterol in th