Scientists have discovered a way to knock out the effects of aging in mice: the study shows that a protein, found in abundant quantities in juveniles, plays a vital role in keeping them healthy.
The decline in the levels of this protein also corresponds to the progressive drop in subjects: vision problems, cognitive decline, weight gain, insulin resistance.
Providing doses of this protein to elderly specimens slowed the decay of function and lengthened their survival by 16%.
As reported in the journal Cell Metabolism, the protein circulating in mice (an enzyme called eNAMPT) plays a key role in the process that supplies cells with energy. Over the years, the latter become less and less efficient in producing this "fuel" (called NAD) necessary for your health.
By supplementing the diet of older mice with eNAMPT, NAD production is maintained at good levels and aging remains at stake.
More activities, more quality sleep
"We have identified a whole new path against aging," says the author of the study, Shin-ichiro Imai, professor of developmental biology at Washington University in St. Louis. "Taking the eNAMPT protein from the blood of younger mice and supplying it to older ones has marked great benefits, including more intense physical activity and better sleep quality - even the hair shines like that of young ones."
Research supported by the National Institute on Aging, the American Federation for Aging Research and the Tanaka Fund also shows gender differences in protein levels, with female specimens much more endowed with eNAMPT.
Unlike studies involving blood transfusions, transferring a single component improves the processes considerably: another element capable of increasing NAD in the body's tissues is a molecule, called NMN, to be administered orally. NMN is already at a later stage, it has been tested on humans for a few months.
"We believe the body has many systems for maintaining good levels of NAD, which is important to the point of regulating how long we live and how healthy we are," says Imai. "In worms, fruit flies, mice and humans, the presence of NAD is essential and decreases over the years."
eNAMPT in action
Imai's research shows that the hypothalamus exerts the most control over aging processes through the management of eNAMPT, which is released into the blood through fatty tissues. The hypothalamus manages life processes such as body temperature, sleep and the circadian cycle, the level of hormones and even thirst.
Tiny particles, so-called extracellular vesicles carry eNAMPT in the blood: eNAMPT levels drop in parallel with the decline of the hypothalamus, and gradually reduce a person's survival time. Simply, in the mouse study, more eNAMPT means more days to live, less eNAMPT means fewer days to live: 1029 days against 881, to be precise.
"We can even predict a guy's lifespan based on his circulating eNAMPT levels," explains Imai. "We do not know how strong this link is in humans, but it is certain that the extracellular vesicles of humans also carry the protein: the phenomenon must be studied".
