Dementia patients have been offered hope that their memory could be repaired after scientists showed that injecting blood from the umbilical cords of human babies restores brain function.

Researchers at Stanford University School of Medicine in the US discovered that cord blood contains an important protein which vanishes as humans get older.  It is believed the protein encourages neuroplasticity in the brain, allowing neurons to adapt and communicate more effectively.

When human cord blood was injected into elderly mice they performed far better in learning and memory tests and even started nesting again, gathering up cotton wads to make beds, an instinctive behaviour that is largely forgotten in old age.

Alzheimer's Society head of research Dr James Pickett said: "Everyone experiences some decline in memory as they get older. The possibility that this process can be reversed by an infusion of young blood sounds like the stuff of science fiction, but this is what the study is beginning to show."

"This study finds that a factor in human umbilical cord blood can enter the brain and restore some of the processes that are essential for forming new memories."