Your Brain Can Still Grow at 94: A 3-Year Study Proves It

Cognitive decline has long been treated as a one-way street. Once the slide begins, the thinking goes, the best you can do is slow it down. A three-year longitudinal study published in Scientific Reports is now pushing back on that assumption hard, finding that brain health improved consistently across nearly 4,000 adults ranging in age from 19 to 94, with gains appearing even in participants in their 80s and 90s.

SMART Training's Effect on Clarity, Connectedness, and Emotional Balance

The improvements were measured using the BrainHealth Index (BHI), a multidimensional metric developed at the University of Texas at Dallas' Center for BrainHealth that integrates roughly 20 validated measures. The BHI tracks three broad domains: Clarity (reasoning, flexibility, and processing speed), Connectedness (social engagement and sense of purpose), and Emotional Balance (stress, resilience, sleep, and life satisfaction). Gains were observed across all three categories, and they held regardless of a participant's age, gender, or education level. People who started with lower scores improved alongside those who began in better shape, suggesting the intervention works across a wide spectrum of cognitive baselines.

The program at the center of the study is called SMART, for Strategic Memory Advanced Reasoning Training. Crucially, SMART is not a brain-game app or a collection of memory puzzles. It is a structured curriculum teaching specific cognitive strategies that participants apply to their actual daily lives. Three modules form the core: strategic attention, which asks participants to identify two tasks each day that require deep thinking and to protect time for them; integrated reasoning, which trains people to extract the big-picture meaning from complex information; and cognitive flexibility, which involves deliberately generating multiple interpretations of situations, including divisive or ambiguous ones. Each module runs approximately 30 minutes and is delivered through short online videos, animations, and exercises. Participants also received quarterly coaching calls to help embed the strategies into daily habits.

Brain Plasticity Benefits Adults of Every Generation, Not Just the Young

The finding that adults in their ninth decade showed meaningful improvement is arguably the study's most striking result. A parallel body of work has already shown that everyday physical activity improves cognitive processing speed in middle age, with a Penn State study reporting gains equivalent to being four years younger. The CDC has similarly noted that regular activity can reduce the risk of cognitive decline and dementia across the adult lifespan. What distinguishes the UT Dallas research is its focus on targeted cognitive strategy training rather than physical movement, and its span across the full arc of adult life.

Sandra Bond Chapman, who leads the Center for BrainHealth, put it directly in a statement accompanying the findings: "For too long, we've operated under the outdated notion that we need to wait until something bad happens to our brain before we do anything for it. This study reminds us that our brain is not defined by age, it is defined by possibility." Lori Cook, another contributor to the research, added that "every brain is as unique as a fingerprint and has potential for growth."

The research team drew on contributors from Trinity College Institute of Neuroscience, the University of California Berkeley, and Johns Hopkins, lending the project a notably broad institutional base. The BrainHealth Project, the umbrella initiative that generated this dataset, launched in 2020 with the explicit goal of understanding how to optimize brain health before symptoms or disease appear.

How a Three-Year Longitudinal Design Strengthened the Evidence

Data from nearly 4,000 adults, assessed twice yearly over three years, gives the study considerably more depth than a single-snapshot survey. Longitudinal studies like the NIH's Baltimore Longitudinal Study of Aging have long been considered the gold standard for understanding how health trajectories shift over time; tracking the same individuals repeatedly allows researchers to separate genuine change from random variation. The BHI assessment itself takes about 90 minutes and draws on validated tools including the Pittsburgh Sleep Quality Index and the Oxford Happiness Questionnaire, grounding the composite score in established instruments rather than proprietary metrics alone.

A dose-response pattern also emerged: participants who engaged most consistently with the platform showed the largest gains. That relationship suggests the improvements are not simply a measurement artifact or regression to the mean, but reflect something closer to a training effect that accumulates with repeated practice.

Self-Selection and Scope Remain the Study's Key Caveats

The authors are careful about what the data can and cannot support. Participants self-selected into an online program, which likely skews the sample toward people who are already motivated and comfortable with technology. That self-selection bias is a meaningful limitation: it is harder to know how the curriculum would perform with less engaged or less digitally confident populations. The study also does not claim to reverse dementia or to substitute for medical care in cases of neurological disease. Researchers working on optimal exercise dose for people with mild cognitive impairment have similarly flagged the difficulty of generalizing intervention findings to clinical populations, a caution that applies here as well.

The evidence tier for this research is best described as emerging: the findings are promising and the sample is large, but replication in more representative, randomly assigned populations will be needed before the field can speak with full confidence.

What Comes Next for the BrainHealth Project and SMART Research

The BrainHealth Project is an ongoing initiative, and the three-year dataset published here is a milestone rather than an endpoint. The research team's broader ambition is to establish proactive brain health as a standard of care in the same way that cardiovascular screening is now routine, intervening long before clinical symptoms emerge. Parallel efforts in the exercise-neuroscience space, including the IGNITE multi-site randomized trial examining how exercise influences brain health in cognitively normal older adults, point toward a converging research agenda: understanding the optimal combination, dose, and timing of both cognitive and physical interventions across the full adult lifespan.

For now, the core message from the UT Dallas data is unusually optimistic for a field often dominated by cautionary findings. Brain health, the study suggests, is neither fixed nor purely age-dependent. It is trainable, and the window for meaningful improvement appears to stay open well into the tenth decade of life.

Evidence rating

EMERGING — 73/100

Three-year longitudinal observational study of approximately 4,000 self-selected adults using a structured online cognitive training curriculum. Without a randomized control group, the study cannot rule out self-selection bias or regression to the mean as explanations for observed BrainHealth Index gains. The SMART curriculum has prior clinical trial support, but this large-scale real-world deployment has not yet been independently replicated at equivalent scale.

References

1. Lori G. Cook, Jeffrey S. Spence, Zhengsi Chang, et al. (2026). Measuring and increasing the brain health span across adulthood: a public health imperative. Scientific Reports. https://doi.org/10.1038/s41598-026-51403-3
2. Can everyday physical activity improve cognitive health in middle age? – Penn State. psu.edu. https://www.psu.edu/news/medicine/2024/11/12/can-everyday-physical-activity-improve-cognitive-health-middle-age/
3. Physical Activity Boosts Brain Health – CDC. cdc.gov. https://www.cdc.gov/aging/publications/features/physical-activity-brain-health.html
4. BLSA History | National Institute on Aging – NIH. NIH. https://www.nia.nih.gov/about/history/blsa-history
5. (2019). Physical activity for cognitive health: what advice can we give to older adults with subjective cognitive decline and mild cognitive impairment?. Dialogues in Clinical Neuroscience. https://doi.org/10.31887/dcns.2019.21.1/nilautenschlager
6. Investigating Gains in Neurocognition in an Intervention Trial of Exercise (IGNITE): Protocol – PMC. NIH. https://pmc.ncbi.nlm.nih.gov/articles/PMC6641772/