Blood from umbilical cords may be medicine’s fountain of youth—at least for mice.

The blood from the cord that connects fetuses to their mothers during pregnancy contains compounds that scientists believe reverses some of the effects of aging, like memory loss. In a paper published (paywall) in Nature Communication on April 19, researchers from Stanford University announced they’ve identified which specific chemicals have these memory-sharpening effects. They believe that one day, these proteins may be able to help people with neurodegenerative diseases, like Alzheimer’s.

In this study, the research team looked at the effects of the liquid part of human blood, called plasma, on mouse brains. The team gave shots of blood plasma from three different sources—people aged 61-82, 19-24, and newborn infants’ umbilical cords (with consent from their parents)—to older mice every four days for two weeks.

They placed the mice in a maze, which consisted of a table filled with holes that would either lead them to a snuggly den or a jarring fall (it wouldn’t be enough to hurt them). Mice that received cord plasma fared better than those who received young adult plasma. Mice who received old plasma did the worst—about the same as mice who had no intervention. This suggests that the youngest plasma somehow improves memory, even after its deteriorated with age.

To figure out which parts of the plasma were actually useful, the team analyzed the different chemicals found in blood plasma at different ages. Specifically, they looked at the proteins that influence how cells talk to each other; old plasma has fewer of these proteins than young plasma, says Tony Wyss-Coray, a Stanford immunologist and co-author of the paper. Specifically, there seems to be a lot more a protein called TIMP2 in younger people. When the researchers injected old mice with TIMP2 alone, they started behaving like young mice again, getting similar similar memory benefits to those mice that had the cord blood injections, suggesting this was the protein at play.

“Human blood, especially young human blood—the youngest we can obtain—has factors in there that can be beneficial in the brain,” says Wyss-Coray. Although this was a mouse model, Wyss-Coray is confident these results could translate to humans. In January, Wyss-Coray and his team concluded a clinical trial in which they injected Alzheimer’s patients with plasma from young adults every week for four months to see if it was safe for patients. They’re still analyzing the results.

Although umbilical cord blood plasma seems to have the most TIMP2, studying it is logistically difficult. Although parents often choose to preserve cord blood—which includes stem cells that can be used to fight diseases later on in life—the plasma is usually discarded. Obtaining it for research would mean a researcher would need to be present at childbirth. To get enough plasma for these sorts of trials would entail invading many people’s privacy. So Wyss-Coray is now focusing on researching plasma from young adults, which still has more TIMP2 than older adults and can be obtained more easily.