Giving old mice blood from young mice can reverse age-related impairments in learning, memory and neuronal function, according to US research.

These findings, published in the journal Nature Medicine, suggest that circulating factors from young blood could reverse the effects of aging in the brain.

Future studies in humans are necessary before similar conclusions can be made about effects in people.

A second set of studies in the journal Science joined a young and old mouse together with a single circulatory system and found that age-related impairments and DNA damage in the muscle stem cells, or satellite cells, of the older mice were reversed.

Tony Wyss-Coray of Stanford University and colleagues found that repeated injection of blood from young, three-month-old mice into old 18-month-old mice can improve their performance in learning and memory tasks.

Heating the blood, which alters the structure of its proteins, before injecting it into older mice abolishes these effects, suggesting a circulating heat-sensitive factor reduces these positive effects.

The aged mice showed a reversal in age-related impairments in their brains at the structural, molecular and functional level.

Of course as blood cells have a 90 day life span this [potentially] would mean a transfusion every 90 days at minimum.