The elusive fountain of youth may be closer to us than science has shown. A new study from the University of Southern California claims that the physical decline in older adults may be reversible after a powerful hormone is found in humans that is expressed during exercise.
The study recently published in Nature Communications discovered that the mitochondrial genome "codes for instructions for regulating a person's physical performance, performance and metabolism as they age". The study, which was conducted in mice, suggests that this regulation may potentially help extend healthier, more physically active lifespans in people of advanced age.
"Mitochondria are known to be the energy source of the cell, but they are also hubs that coordinate and optimize metabolism by actively communicating with the rest of the body," said Changhan David Lee, co-author of the study, assistant professor at USC Leonard Davis School of Gerontology said on the university website. "As you get older, this communications network seems to break down, but our study suggests that you can restore that network or rejuvenate an older mouse to be as fit as a younger one."
The scientists looked at MOTS-c, a hormone that mimics the effects of exercise. The research team tested how injections of MOTS-c affected mice of different ages by measuring physical performance and performance in young, middle and old mice. When the mice were exposed to physical challenges such as running on an accelerated treadmill, mice of all ages that received MOTS-c treatment fared significantly better than untreated mice of the same age and mice fed a high-fat diet.
In humans, the researchers collected skeletal muscle tissue and plasma from seated, healthy young male volunteers who exercised on a stationary bike before, during, and after exercise. Their MOTS-c levels increased significantly in the muscle cells after training and remained slightly elevated even after a four-hour break.
The results, according to the researchers, give promising hope to aging adults who may have physically regressed, that they may be able to regain some of the strength and physical performance they had decades before.
"Indicators of physical decline in humans, such as decreased stride length or walking ability, are strongly related to mortality and morbidity," said Lee. "Interventions against age-related decline and frailty that are applied later in life would be translationally more practical compared to lifelong treatments."