A medical breakthrough by British scientists has been hailed as a "turning point" in the fight against Alzheimer's disease.

The study by scientists at the UK's Medical Research Council Toxicology Unit at the University of Leicester raised the prospect that a pill could be used in the future to prevent the destruction of brain cells, part of the cause of degenerative brain disease.

The study, published Thursday in the journal "Science Translational Medicine," scientists have found the compound which can effectively "switch off" the defective neurological processes in the brains of dementia patients that lead to the death of brain cells.

This medial breakthrough could create new treatments to millions of people who suffer from the condition. However, more work is needed to develop a drug that could be taken by patients.

"We're still a long way from a usable drug for humans - this compound had serious side effects," noted lead researcher Giovanna Mallucci, in a university press statement. "But the fact that we have established that this pathway can be manipulated to protect against brain cell loss first with genetic tools and now with a compound, means that developing drug treatments targeting this pathway for ... neurodegenerative diseases is now a real possibility."

In the meantime, researchers gave an oral drug-like compound to mice with dementia-like symptoms, hoping to block the defective brain-signalling processes in the same way. The compound, which had originally been developed by GlaxoSmithKline for a different purpose, was able to enter the brain from the bloodstream and stop the disease from spreading to the rest of the brain. The pill also produced weight loss in the mice and mild diabetes, due to damage to the pancreas, the researchers said.

"Our previous study predicted that this pathway could be a target for treatment to protect brain cells in neurodegenerative disease," said Mallucci. "So we administered a compound that blocks it to mice with [dementia]. We were extremely excited when we saw the treatment stop the disease in its tracks and protect brain cells, restoring some normal behaviors and preventing memory loss in the mice."