Exercise Boosts Attention and Slows Epigenetic Aging in Breast Cancer Survivors

One in three breast cancer survivors will experience cognitive problems at some point after their diagnosis, a burden that can include difficulties with attention, memory, processing speed and other domains of thinking. Researchers believe these symptoms arise from a convergence of factors: the direct effects of cancer treatment, chronic inflammation, hormonal shifts, fatigue and psychological stress. Unlike many side effects that fade once therapy ends, cancer-related cognitive impairment can persist for years, interfering with work, family life and everyday activities, and diminishing overall quality of life. For a population that now numbers in the millions worldwide, the search for accessible, non-pharmacological interventions has become an urgent priority in survivorship research.

A pair of new studies from University of California San Diego, including investigators at Moores Cancer Center, now offers some of the strongest evidence to date that physical activity may help. Drawing on a single randomized clinical trial, the two papers, published on September 30, 2026 in the Journal of the National Cancer Institute, report that a 12-month exercise intervention was associated with measurable improvements in attention and memory among breast cancer survivors. A companion analysis of blood samples from the same trial suggests that exercise may also slow epigenetic aging, altering DNA methylation patterns that serve as molecular markers of biological age. Together, the findings point to a plausible biological pathway linking movement to brain health after cancer treatment.

The underlying trial was designed to test a straightforward question: could increasing physical activity improve cognitive health in survivors who needed it most? The researchers enrolled 253 breast cancer survivors who had completed active treatment and who both reported cognitive difficulties and logged low levels of physical activity at baseline. Participants were randomly assigned to one of two remotely delivered programs. The exercise arm used fitness trackers to monitor daily activity and provided individualized coaching designed to help participants work toward 150 minutes of moderate-to-vigorous physical activity per week, the threshold recommended by major public health guidelines. The comparison group received a health and wellness program that included regular contact with a health coach but no exercise coaching, allowing the trial to isolate the specific contribution of physical activity from the benefits of sustained attention and social contact.

The results were nuanced but encouraging. As expected, the exercise group increased its moderate-to-vigorous physical activity more than the health and wellness group over the course of the year. Both groups showed meaningful improvements across all cognitive measures, and on the study’s two primary outcomes, processing speed and self-reported cognition, there were no significant differences between the arms. However, the exercise group demonstrated greater improvements in attention at both the six-month and 12-month assessments, a benefit that was sustained across the full study period. The exercise group also showed greater improvement in memory at six months, although that advantage was not maintained at 12 months, converging with the comparison group by the end of the trial. Executive function showed no significant differences between groups at either time point.

The sustained attention benefit carries particular weight, according to the study’s lead author. Attention is the cognitive gateway through which nearly all other mental work passes, supporting the ability to follow conversations, absorb new information and complete tasks without errors. Sheri Hartman, PhD, professor at the UC San Diego Herbert Wertheim School of Public Health and Human Longevity Science and a member of Moores Cancer Center, emphasized that the improvements were achieved with what she described as a modest, attainable increase in physical activity, rather than a demanding training regimen. That distinction matters for survivors, many of whom contend with fatigue, lymphedema or other treatment sequelae that can make intensive exercise programs difficult to sustain.

The companion study took the investigation to the molecular level. The researchers analyzed a random subset of 124 participants who provided blood samples at the beginning of the study and at the six- and 12-month follow-ups. From these samples they computed epigenetic age, an estimate of biological age derived from DNA methylation patterns across the genome. Epigenetic clocks, the statistical models used to convert methylation data into age estimates, have become a widely used tool in geroscience because they capture biological wear that can diverge substantially from chronological age, the actual number of years a person has lived. In this cohort, the divergence was striking at baseline: participants in both groups had epigenetic ages that were, on average, about 8.7 years older than their chronological ages.

Over the 12-month study period, the two groups’ molecular trajectories diverged. Using two distinct epigenetic clocks, the researchers found that participants in the exercise group experienced slower rates of epigenetic aging than those in the health and wellness group. The magnitude of the difference was considerable: the health and wellness group accumulated nearly 10 months of epigenetic aging over the course of a year, consistent with a normal pace of biological aging, while the exercise group accumulated only about one month. In other words, the molecular markers of aging in the exercisers advanced at a fraction of the rate seen in their peers, despite both groups starting from equivalent epigenetic baselines.

Perhaps most intriguingly, the two studies appear to intersect. Across both trial arms, faster epigenetic aging was associated with less improvement in attention and worse self-reported cognition, suggesting that the molecular clock and cognitive performance are not independent phenomena. The researchers interpret this pattern as evidence that exercise may help buffer against some of the cognitive effects associated with accelerated epigenetic aging, potentially explaining, at least in part, how physical activity protects brain function after cancer treatment. Paula Desplats, professor of neurology at The Ohio State University, adjunct professor of neuroscience at UC San Diego School of Medicine and co-senior author of the companion study, noted that the effects of exercise were measurable both at the molecular level and in cognitive performance, and that the changes in epigenetic aging markers suggest even a relatively modest increase in physical activity may influence biological processes that help keep the brain healthy.

The scientific significance of these findings lies in their convergence. Randomized trials of exercise in cancer survivors have produced mixed cognitive results in the past, partly because self-reported outcomes are vulnerable to placebo effects and because objective neuropsychological measures can be insensitive to change over short intervals. By pairing cognitive testing with molecular biomarkers drawn from the same randomized cohort, the UC San Diego team has assembled a two-pronged line of evidence: a sustained, objectively measured improvement in attention, and a dramatic slowing of epigenetic aging that correlates with cognitive trajectory. DNA methylation is responsive to environmental and behavioral exposures, and exercise is known to influence inflammatory pathways, metabolic health and neurotrophic signaling, all of which could plausibly feed into methylation changes and, downstream, into brain function.

The researchers are careful to frame the results as preliminary in important respects. Larger studies are needed to confirm the findings, to determine whether changes in epigenetic aging directly contribute to cognitive benefits rather than merely tracking alongside them, and to understand how exercise might sustain improvements in attention and memory over longer horizons. The memory benefit, which appeared at six months but not 12, raises questions about dose, duration and the cognitive domains most responsive to activity. Hartman noted that the ultimate goal is to understand not just whether exercise helps, but who is most likely to benefit, how much activity is needed and what changes in the body might explain those benefits, knowledge that could enable more targeted approaches to supporting cognitive health after cancer treatment. The studies were funded in part by the National Cancer Institute of the National Institutes of Health, and the authors declared no conflicts of interest.

Subject of Research: Effects of a 12-month exercise intervention on cognition and epigenetic aging in breast cancer survivors

Article Title: Exercise program supports better attention and slows biological aging in breast cancer survivors

Article References: Exercise program supports better attention and slows biological aging in breast cancer survivors. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: breast cancer, cancer survivors, cognitive function, attention, memory, exercise intervention, epigenetic aging, DNA methylation, epigenetic clocks, randomized clinical trial, survivorship, physical activity