What is Creatine?
Before diving into the study, it’s helpful to understand what creatine is. It's not a synthetic steroid but a naturally occurring compound made from amino acids. Your body produces about one gram of it per day, and it's also found in foods like red meat
and fish. Its primary job is to help create energy, specifically for short bursts of high-intensity activity. Think lifting a heavy weight or sprinting. About 95% of your body's creatine is stored in your muscles, ready to be called upon when you need that quick power. For decades, athletes have used creatine supplements, most commonly creatine monohydrate, to top up these stores, allowing them to train harder and recover faster.
The Texas A&M Study Explained
Researchers at Texas A&M University, led by Dr. Richard Kreider, who has studied creatine for over 30 years, turned their attention to a demographic often overlooked in sports nutrition: adults aged 45 to 65. In a recent 12-week study, they examined the effects of daily creatine supplementation. The results were notable. Participants who took creatine gained lean tissue and improved their strength—measured by leg and bench press—even without being part of a structured exercise program. For those who did follow a workout regimen of resistance and aerobic training, the gains were even more significant. The study also found that when combined with a calorie-reduced diet and exercise, creatine helped participants gain nearly three pounds of lean tissue while losing fat mass, a significant finding for preserving muscle during weight loss.
Why the Gains Aren't Universal
Here's the critical nuance from the headline: creatine doesn’t work for everyone. The phenomenon is well-documented in the scientific community, with studies suggesting that roughly 20-30% of people are considered "non-responders." This means they experience little to no performance benefit from supplementation. The reason isn't a flaw in the supplement but rather a matter of biology. The primary factor appears to be your baseline creatine level. If your muscle stores are already near full capacity, either through your body's natural production or a diet rich in meat and fish, there's simply less room for the supplement to add more. Vegetarians and vegans, who get very little creatine from their diet, often see the most dramatic response.
Responders vs. Non-Responders
Digging deeper, the difference between a "responder" and a "non-responder" can come down to muscle fiber type and even genetics. Research has shown that individuals with a higher percentage of fast-twitch muscle fibers—the kind used for powerful, explosive movements—tend to have more storage capacity for creatine and respond better to supplementation. One study found that responders had a significantly higher proportion of these fibers compared to non-responders. Essentially, if your biological tank was already close to full before you started supplementing, you're unlikely to notice a major difference. It's not a failure of the supplement, but an indication that your baseline levels were already high.
Is Creatine Safe for This Age Group?
For healthy individuals, creatine is considered one of the most well-researched and safe supplements on the market. Extensive reviews, including a 2025 analysis by Dr. Kreider and his colleagues that looked at hundreds of clinical trials, have found no significant difference in reported side effects between those taking creatine and those taking a placebo. The main side effect is often a slight weight gain from water retention as the supplement pulls water into the muscle cells. However, the key word is "healthy." Individuals with pre-existing kidney conditions should consult their doctor before considering creatine, as its effects in this population are not as well-studied.
