Original story: UT Health San Antonio Newsroom
By Claire Kowalick
SAN ANTONIO (October 2, 2025)
It is often said that exercise is the best medicine, but for many older adults, it can be a prescription that is increasingly difficult to take. Age-related physical and mental health challenges frequently make regular activity hard to sustain.
A study published in Dietetics in August 2025, by scientists at UT Health San Antonio, the clinical enterprise of The University of Texas at San Antonio, explored whether adding branched-chain amino acids (BCAAs) to an exercise program could improve outcomes for older adults. In a small, randomized, double-blind, placebo-controlled trial, the team found that BCAA supplementation improved performance, reduced fatigue, and alleviated depression symptoms for many participants.
Inflammation and amino acids
“We’ve been studying for years how inflammation contributes to functional decline with normal aging or during disease, and among the many factors implicated in this process, the metabolism of amino acids appears to play an important role,” said study co-author Jason O’Connor, PhD, an associate professor in the Department of Pharmacology who also has a joint appointment at the Veterans Administration through the Geriatric Research Education and Clinical Center.
His research focuses on how inflammation impairs central nervous system function. BCAAs — leucine, isoleucine, and valine — are essential amino acids that not only serve as the building blocks of protein and muscle but also appear to play specific roles in inflammation and brain health.
“During inflammation, the metabolism of amino acids changes in a way that directly and indirectly impacts other processes. We are interested in getting some additional clarity about the brain-based component to fatigue versus the physical factors,” O’Connor said.
Story continues:
Pilot study: Branched-chain amino acids may help physical, mental fatigue in older adults