New research in mice uncovers a previously unknown "pathway toward healthy aging." A circulating protein from the blood of young mice led to health improvements and visible signs of rejuvenation when researchers gave it to aging mice, Medical News Today.

As well as hair loss, wrinkles, and lessening mobility, less visible, underlying bodily changes also characterize the aging process.

One of these changes is the loss of a kind of "fuel" that keeps the body healthy — the so-called nicotinamide adenine dinucleotide (NAD).

NAD plays key roles in metabolism, DNA repair, and overall aging and longevity. With time, however, aging cells find it harder to produce energy, in general, and NAD, in particular.

But, in the energy-making process comes another critical player — an enzyme called eNAMPT. New research finds that taking eNAMPT from the blood of younger mice and giving it to older mice boosts NAD levels and staves off aging.

The findings appear in the journal Cell Metabolism. Dr. Shin-ichiro Imai, Ph.D., who is a professor of developmental biology at Washington University School of Medicine in St. Louis, is the senior author of the study.