An oral pill could naturally stimulate the body to improve muscle health. Lead author David Marcinek said: “This is relevant both to people with chronic diseases and people who want to be more active later in life.”
The chemical urolithin A is normally produced naturally in the gut when digesting foods such as pomegranate, nuts and berries. Age and disease can impact the ability of our bodies to synthesise it.
Marcinek, a professor of radiology at the University of Washington School of Medicine, explained that urolithin A is believed to activate “mitophagy”, a quality control system in the muscles that otherwise degrades with age.
He said: “Mitochondria are like batteries that power the cells in your body, but over time they break down.
“The process of mitophagy recognizes this failure and proactively tears down the mitochondria, reducing it to elemental components that a cell can reuse.
“But with aging, mitophagy becomes less efficient and your body accumulates this pool of failing mitochondria.
“It’s one way that muscles become less functional as we age.”
The results are limited in scope and did not produce an effect across the entire body.
Endurance exercises using the hands and legs saw improvements over the placebo group.
Marcinek explained: “Even though we did not observe an effect of the supplement in whole body function these results are still exciting because they demonstrate that just taking a supplement for a short duration actually improved muscle endurance.
“Fatigue resistance got better in the absence of exercise.”
There was also a reduction in biomarkers of mitochondrial disorders that Marcinek believes represent an improvement in general metabolic health.
One group that the reserachers believe will benefit strongly are those who want to exercise but are prevented by poor health.
Urolithin A supplements could get them over the hurdle and enable strengthening exercises to build more progress from.
“Just getting them over that point where exercise is possible – a walk around the block or climbing some stairs – might help a person build their own health,” Professor Marcinek said.
Funding for the research was provided by Amazentis, a company that manufactures urolithin A supplements.
The study was published in JAMA Network Open.
Mitochondria are believed to have once been independent single celled organisms.
At some point, they were engulfed into more complex eukaryotic cells and developed a cooperative relationship.
Some relics of this can be found in that mitochondria retain their own genome.
This has been very useful to genetics researchers as the mitochondria evolve at a different speed to the rest of the genome, and mitochondrial changes can be used to track genetic changes over time.