Memory loss caused by Alzheimer’s can also be reversed by a protein produced by the body to fight arthritis.

In some cases there is complete reversal of memory impairment after treatment, the University of South Florida scientists in the US who conducted the study have found.

The protein GM-CSF is commercially available and known as leukine, reports the Telegraph.

This protein stimulates scavenger cells in the body, when people with rheumatoid arthritis suffer swollen joints. In mice tests, these cells removed deposits left by Alzheimer’s in the brain.

Professor Huntingdon Potter, a molecular medicine expert involved in the Florida study, said, “Our findings provide a compelling explanation for why rheumatoid arthritis is a negative risk factor for Alzheimer’s disease,” according to the Journal of Alzheimer’s Disease.

Scientists used two groups of mice, one healthy and the other engineered to develop Alzheimer’s-like symptoms, including memory loss.

Half the mice were injected with GM-CSF, the other injected with a placebo saline solution.

After 20 days, researchers found the memories of Alzheimer’s mice injected with the protein had improved substantially compared with mice treated with a placebo.

“We were pretty amazed that the treatment completely reversed cognitive impairment in 20 days,” said Tim Boyd, who led the study.