While the search for a real life fountain of youth continues, scientists have recently confirmed the transfusion of blood from a young body to an old body can reverse the aging process.

At least in the case of mice.

While the experiments preformed by researchers at the Harvard Stem Cell Institute are currently only helping mice feel younger, the results indicate a new protein can make the failing hearts in aging mice appear more like those of young health mice.

The scientists conducting the study are confirming the transfusion of the blood of young mice to older ones did indeed undo age-related impairments in the brain including reversing declines in learning and memory and also boosting the creation of new neurons. They also reported that a protein in the blood of young mice improved the ability of old ones (comparable to a 70-year-old person) to exercise.

"This should give us all hope for a healthier future," said Doug Melton, co-chair of the study at Harvard Stem Cell Institute. "We all wonder why we were stronger and mentally more agile when young and these two unusually exciting papers actually point to a possible answer: the higher levels of the protein GDF11 we have when young. There seems to be little question that, at least in animals, GDF11 has an amazing capacity to restore aging muscle and brain function."

The researchers added they expect to have GDF11 in initial human clinical trials within three to five years.

The team at the Harvard Stem Cell Institute had reported last year that when exposed to the blood of young mice the weak enlarged hearts of older mice returned to a more youthful size and their function improved. Theses recent experiments were a continuation of those discoveries.

"I think the study is quite wonderful," added Nobel Prizing winning neuroscientist Eric Kandel of Columbia University, who was not part of the study. "It suggests there may be diffusible factors in the blood that are age-dependent, and if you can isolate these substances you might be able to give them as dietary supplements."