Remember that phrase, “use it or lose it”? It certainly applies to our strength as we get older. The less we exercise, the weaker our muscles and bones become. But what if you have a disease or condition that prevents you from getting enough exercise? If you don’t have the strength to complete a workout, or simply want to regain the strength you lost due to aging, you may want to consider taking a urolithin A supplement.
What is urolithin A?
As explained in a 2021 scientific review from Trends in Molecular Medicine, urolithin A is a natural compound created by our gut microbiome. When we eat foods such as pomegranates, raspberries, and walnuts — which are rich in certain polyphenols (plant micronutrients) — bacteria in our gut transform those polyphenols into urolithins. Urolithins, like urolithin A, then circulate through the body and improve the health of our cells.
However, the polyphenols that get converted into urolithin A have a very low bioavailability. That means the body has a difficult time absorbing and using them. (Your gut’s ability to absorb nutrients also depends on diet, age, genetics, and any diseases you may have.) So, eating foods high in polyphenols doesn’t necessarily mean that our bodies will be able to absorb those plant nutrients and turn them into urolithin A.
This is a problem, because a growing body of research suggests that urolithin A is extremely important for cellular health. It can reduce cell aging, lower inflammation in the body, and potentially improve the function of muscles.
That’s where supplements come in. According to the authors who wrote the review from Trends in Molecular Medicine, urolithin A supplements can do a great deal for cell health. Several studies show that in supplement form, this natural compound enhances muscle strength, prevents neurodegeneration (the loss of brain cells), and even protects against obesity and type 2 diabetes.
How does urolithin A improve muscle health?
Studies have shown that urolithin A improves the health of the mitochondria in our cells. Mitochondria are organelles, or “tiny organs” inside of cells that work like batteries to power the cell. Our cells can’t function without them!
However, urolithin A doesn’t directly create strong and healthy mitochondria. Instead, it stimulates your cells to remove damaged mitochondria. Once the “garbage” is cleared out, the cell can create new mitochondria that keep everything functioning well.
Testing the Benefits
In a recent study published in JAMA Network Open, researchers from the University of Washington School of Medicine predicted that urolithin A supplementation can improve muscle health in older adults. They also theorized that it would improve the health of mitochondria. (Remember: mitochondria are like batteries, giving our cells energy.)
To test out these supposed benefits, the researchers recruited 66 adults between 65 and 90 years of age. At the beginning of the study, they measured how much urolithin A the volunteers had in their bodies.
Then, they measured the participants’ muscle strength, first in a specific area — their hands — and then in their entire body. They tested how many repetitions of a hand exercise each participant could complete until exhaustion. Next, they had participants walk around a course for as many laps as possible in six minutes.
During the hand exercise, the researchers tested the health of each participant’s cell mitochondria. How could they test mitochondrial health? They used noninvasive technology to measure the presence of adenosine triphosphate (ATP) in the participants’ hand muscles. (Think of ATP as energy for the cell. Mitochondria convert sugar into ATP so that the cell has energy to function.)
At the onset of the study, only some of the 66 participants had adequate levels of ATP in their hand muscles. This suggested that many volunteers didn’t have enough energy in their muscles, and that the mitochondria in the muscle cells weren’t entirely healthy. The researchers also measured how much urolithin A the volunteers had in their bodies.
The researchers divided participants into two groups: those who received a urolithin A supplement and those who received a placebo. Neither the researchers nor the participants knew who received the real supplement. In addition, those who received the real supplement took 1,000 milligrams of urolithin A daily for four months.
The Study Results
After four months, the investigators again had the participants complete a six-minute walk and hand exercises. After analyzing the data, they concluded that urolithin A did not seem to improve the muscles’ ability to create energy. (The team suspected that the placebo group performed better on both exercise tests because they believed they were taking the urolithin A supplement and that it was doing some good.)
However, the researchers did find that taking urolithin A supplements long-term significantly improved muscle endurance. In other words, volunteers who took the real supplement didn’t get fatigued as quickly as the placebo group. This suggests that urolithin A has a direct, positive effect on muscle performance, even when a person isn’t exercising regularly.
Curious about taking urolithin A supplements? It’s always a good idea to speak with your doctor first. Your physician may be able to recommend a specific brand and specific dosage. Supplements tend to have other ingredients in them as well, so checking those labels is important. Still, it’s great to know that those of us who struggle to improve our muscle strength with exercise alone may have another option.