Can Better Sleep Slow Aging? A 2026 UCLA Study on CBT-I and Biological Age

The science connecting restorative sleep to how fast your body ages, and why it's never too early to take insomnia seriously.

Good sleep can slow cellular aging.

Sleep is not a luxury, it's foundational infrastructure for your health. Usually, the argument for getting better sleep rests on things we all can feel: mood, focus, patience, energy. But this past September, researchers at UCLA Health published findings in The Lancet Healthy Longevity journal, showing that treating insomnia with cognitive behavioral therapy didn't just improve how people slept. In their researcher, it appeared to slow down how fast their bodies were aging at the cellular level.

Admittedly, I am a bit biased. And, as a CBT-I (cognitive behavioral therapy for insomnia) sleep coach, I believe this approach deserves far more attention than it gets. All that aside, however, I want to walk through what the researchers at UCLA actually found, why it matters, and why the earlier you address sleep problems, the more you may stand to gain.

The Study

Let's start with the basics. CBT-I is widely considered the gold-standard, first-line treatment for chronic insomnia, the kind recommended by the American College of Physicians before turning to sleep medication (Qaseem et al., 2016). And, rather than relying on pills, it works by addressing the thought patterns, habits, and physiological responses that underlie insomnia and trouble sleeping.

In UCLA’s randomized controlled clinical trial, researchers assigned nearly 100 older adults with insomnia to one of two groups: one received CBT-I, and the other received sleep education, a more general, lower-intensity comparison treatment. According to the researchers, between 10% and 25% of adults over the age of 65 in the United States live with clinically diagnosable insomnia—which is somewhere between 6.5 and 16 million people. Unfortunately, insomnia (especially) for older adults is far too often treated as a quality-of-life issue instead of something with deeper physiological consequences. And, the UCLA study (very helpfully) leaned into those deeper consequences.

Researchers weren't just measuring whether people slept better, though that outcome mattered too. They found that older adults who underwent CBT-I were more likely to experience insomnia remission and showed a slower pace of biological aging than those in the sleep education control group.

Research shows that CBT-I can effect how we age, effectively slowing and in some ways reversing our epigenetic clock.

Biological Aging, Epigenetic Clocks, and UCLA’s Findings

To understand what "biological aging" means here, it helps to know a little about the tool researchers used to measure it: something called an epigenetic clock. These “clocks” work by analyzing DNA methylation, a process that affects how genes are turned on or off throughout the body. Epigenetic clocks measure these methylation patterns to estimate biological age, which can diverge meaningfully from a person's chronological age. In this study specifically, researchers used a particular epigenetic clock called DunedinPACE, and found that productively engaging in CBT-I was associated with a slower pace of aging on this measure over a two-year period. At the same time, insomnia remission (getting better, more restorative sleep) rose nearly threefold compared to the control group.

In plain terms: the people whose insomnia actually improved because of CBT-I weren't just reporting that they felt more rested. Their cells showed measurable signs of aging more slowly than their peers who didn't get CBT-I.

This Isn't an Isolated Finding

If this were the only study pointing in this direction, I'd encourage some healthy skepticism (I happen to be a big fan of skepticism). But, this UCLA study actually builds on a growing, consistent body of research connecting poor sleep to accelerated biological aging.

An analysis of nearly 4,000 older adults in the Health and Retirement Study (a study that survey supported by the National Institute on Aging and the Social Security Administration) found that short sleep and insomnia were associated with accelerated epigenetic age (Kusters et al., 2024). A separate study of older adults found that insomnia was associated with accelerated epigenetic clocks, along with a shortened DNA methylation estimator of telomere length, a marker closely tied to cellular aging. Still other researchers have approached the question from a different angle entirely, using a method called Mendelian randomization to test for a causal relationship rather than just an association. That research found that self-reported insomnia appeared to speed up biological aging as measured by a “clock”/tool called GrimAge, and identified a bidirectional relationship between insomnia and epigenetic aging acceleration (meaning that poor sleep and accelerated aging effect each other).

A broader review of this research area offers clear conclusions: sleep disturbances, including insomnia, sleep apnea, shift work, and more have been linked to accelerated biological aging through changes in DNA methylation that affect inflammation, oxidative stress, telomere maintenance, and immune function. But, this same research suggests that these methylation changes may be at least partially reversible. And that essentially means that there is real opportunity to slow biological aging simply by getting better sleep. The UCLA study appears to confirm this in a controlled, measurable way (which is a really big deal).

Why This Matters Beyond the Lab

I am not going to fully unpack the mechanics of DNA methylation for you (I honestly couldn’t even I was interested in trying). However, I can say that the problem of insomnia rarely stays contained to nighttime. It bleeds into mood, memory, relationships, work performance, and a host of aspects of physical health. This research adds another, deeper layer to that picture. It suggests that the cost of unaddressed insomnia may extend all the way down to how our bodies age at a cellular level, and that treating it properly may do more than help you feel better tomorrow. It may change your trajectory.

Dr. Judith Carroll, the study's lead author, put it simply: "Just as we counsel patients on physical activity and diet to support healthy aging, this points to sleep as another important behavior worth targeting to improve health." Personally, I'd go a step further. Based on what I see in my own practice, sleep isn't just one factor among many. It's the factor that makes every other aspect of our health actually work. When sleep is off, everything is affected.

Why Earlier Is Better

The earlier we can start to sleep well, the better off we are.

UCLA’s study focused specifically on older adults, a population considered particularly vulnerable to the biological effects of poor sleep. That's an important population to study, but it also raises a natural question. If treating insomnia later in life can measurably slow biological aging, what might be possible for someone who addresses it much earlier, before chronic sleep disruption has had years to build up?

We don't yet have a definitive answer to that question, and I don’t want to overstate research that is still (by its own authors' admission) early. But the broader pattern in this field, that sleep-related epigenetic changes may be reversible and that the biological cost of insomnia accumulates over time, points toward a reasonable, low-risk conclusion—the earlier you invest in genuinely good sleep, the more opportunity you give yourself to benefit.

(This is a big part of why I built my CBT-I coaching practice the way I did. It's a proactive, structured, compassionate, personal, evidence-based approach that works whether you're 70 and dealing with decades of poor sleep, or 40 and noticing the first signs that your sleep isn't what it used to be.)

The Bottom Line

Good sleep has always been something we intuitively understood as important. What research like this UCLA study does is give us a much sharper picture of just how deep that importance runs. Good sleep doesn't just mean fewer groggy mornings. Increasingly, the evidence suggests it means longer, healthier possibilities for everything else in your life.

Sweet dreams, and be well.

Adam Scheldt is a holistic counselor and CBT-I sleep coach based in Kenmore, New York, serving clients in person and online.

References

Carroll, J. E., et al. (2026). The Lancet Healthy Longevity. https://doi.org/10.1016/j.lanhl.2026.100861

Kusters, C. D. J., Klopack, E. T., Crimmins, E. M., Seeman, T. E., Cole, S., & Carroll, J. E. (2024). Short sleep and insomnia are associated with accelerated epigenetic age. Psychosomatic Medicine, 86, 453-462. https://doi.org/10.1097/PSY.0000000000001243

Qaseem, A., Kansagara, D., Forciea, M. A., Cooke, M., & Denberg, T. D. (2016). Management of chronic insomnia disorder in adults: A clinical practice guideline from the American College of Physicians. Annals of Internal Medicine, 165(2), 125-133. https://doi.org/10.7326/M15-2175

Rivero-Segura, N. A., Rodriguez Cuartas, J. D., Garcia-delaTorre, P., Sanchez-Garcia, S., Ramirez-Aldana, R., & Gomez-Verjan, J. C. (2025). Insomnia accelerates the epigenetic clocks in older adults. GeroScience, 47(6), 6777-6788. https://doi.org/10.1007/s11357-025-01608-7

Sleep and aging: The role of DNA methylation [Review article]. (2026). ScienceDirect. https://www.sciencedirect.com/science/article/pii/S0531556526001841

Sleep traits causally affect epigenetic age acceleration: A Mendelian randomization study. (2025). Scientific Reports. https://www.nature.com/articles/s41598-024-84957-1

UCLA Health. (2026, September 8). Cognitive behavioral therapy may reduce biological aging among older adults with insomnia [Press release]. https://www.uclahealth.org/news/release/cognitive-behavioral-therapy-may-reduce-biological-aging