Urolithin A Supplementation May Help Improve Muscle Endurance in Older Adults: US Study

People over age 65 who took a daily supplement of 1,000 mg urolithin A for four months experienced a significant improvement in muscle endurance compared with those who used placebo.

Aging results in loss of muscle mass, muscle strength, and physical function. Taking oral supplement Urolithin A may help improve muscle endurance and mitochondrial health in older adults or who have chronic diseases that make exercise difficult, suggested a new study published in JAMA Network Open.

Urolithin A is a natural compound produced by our gut bacteria from ingested polyphenols, ellagitannins (ETs) and ellagic acid (EA), which are found in pomegranates, berries and nuts. This compound is also produced and sold by dietary supplement companies. The urolithin A supplement used in the trial is manufactured by Amazentis, of Lausanne, Switzerland, which also funded the study.

In preclinical studies, Urolithin A has been found to protect against aging and age-related conditions affecting muscle, brain, joints, and other organs.

Urolithin A boosts mitophagy,metabolism

Mitochondria are considered the powerhouses of the cell as they help generate energy from food that the cell can use. Aging results in a decline in mitochondrial function. Urolithin A stimulates mitophagy, or what lead author David Marcinek called "mitochondrial quality control."

Marcinek, a professor of radiology at the University of Washington School of Medicine, explained: Mitochondria are like batteries that power the cells in your body, but over time they break down. Mitophagy is a process that recognizes this failure and proactively tears down the mitochondria, reducing it to elemental components that a cell can reuse. As we age, mitophagy becomes less efficient, leading to the accumulation of failing mitochondria in the body. This is a reason why muscles become less functional as we get older.

The study included 66 people over age 65 who were randomized to receive a placebo or a daily supplement of 1,000 mg urolithin A for four months. Those who received urolithin A experienced a significant improvement in muscle endurance (number of muscle contractions until fatigue) for both hand and leg skeletal muscles compared with those who used placebo, the investigators said.

Marcinek noted that even though they did not observe an effect of the supplement in whole body function, the results did demonstrate that taking the supplement for a short duration actually improved muscle endurance.

Additionally, the supplement was found associated with a significant reduction in several acylcarnitines and ceramides implicated for their roles in metabolic disorders involving mitochondria. These changes indicate that the treatment affects improved their general metabolism, Marcinek said.

Urolithin A supplements may benefit people who cannot get the exercise they want due to poor muscle health or disease, he added.

Conclusion

The study indicated that urolithin A was safe and well tolerated as well as beneficial for muscle endurance and mitochondrial health in older adults. Further, it suggested the supplement may be used to counteract age-associated muscle decline. However, they stressed that future work is needed to confirm this finding.