Quality sleep may protect brain structure in people with diabetes and heart conditions
A large-scale study of over 400,000 individuals found that those with type 2 diabetes, heart disease, or stroke who slept well showed better cognitive performance and greater brain volume compared to peers with poor sleep. The benefits were especially strong in people with cardiometabolic diseases, suggesting sleep may help offset neurological damage from these conditions. MRI data confirmed that good sleepers had more gray and white matter, even after adjusting for other health factors.
A large-scale study involving over 400,000 individuals from the UK Biobank found that people with type 2 diabetes, heart disease, or stroke who reported good sleep quality exhibited better cognitive performance and greater brain volume compared to those with similar conditions but poor sleep. The analysis included nearly 35,000 participants who underwent MRI scans, which revealed significantly higher gray and white matter volumes in well-sleeping individuals, even after adjusting for age, sex, and other health factors. The study, published in the Journal of the American Heart Association in 2026, assessed sleep through five self-reported indicators: duration, circadian rhythm, insomnia, snoring, and daytime sleepiness. The benefits were most pronounced among those with cardiometabolic diseases, suggesting that sleep may help counteract neurological damage linked to these conditions. Researchers from Karolinska Institutet, including Abigail Dove from the Aging Research Center, emphasize that improving sleep is a practical and accessible intervention for older adults facing high risks of cognitive decline.
This research builds on growing evidence linking poor sleep with neurodegeneration and cardiovascular risk, particularly in aging populations. Prior studies have shown associations between sleep disruption and increased dementia incidence, but this study uniquely isolates the protective effect of good sleep within high-risk groups. The findings may influence clinical guideli
This study could influence public health messaging by elevating sleep hygiene as a critical component of care for millions managing diabetes, heart disease, or stroke. Given that these conditions are widespread among older adults, promoting better sleep may reduce long-term cognitive decline and healthcare burden. Clinicians may begin routinely assessing sleep quality in at-risk patients, potentially shifting preventive care models toward holistic lifestyle interventions. The findings may also affect pharmaceutical and wellness markets, encouraging development of sleep-focused digital health tools or therapies tailored to cardiometabolic patients. A comparable precedent is the shift in cardiovascular medicine following research on exercise and diet—what was once supplemental is now central to treatment protocols. However, unlike those established interventions, sleep’s role remains underutilized in clinical practice. The next step may involve large-scale trials testing whether structur