A comprehensive study from Karolinska Institutet found that poor sleep accelerates brain aging, with each point decrease in sleep quality score linked to the brain appearing about one year older than the actual age.

The research revealed that a one-point decline in sleep quality correlates with a six-month increase in the gap between brain age and chronological age, emphasizing sleep's role in brain health.

Biomarkers of systemic inflammation explained just over 10% of the association between poor sleep and increased brain age, indicating inflammation as an important but not sole factor.

Sleep quality was assessed through self-reported factors like sleep duration, insomnia, snoring, chronotype, and daytime sleepiness, categorizing participants into healthy, intermediate, or poor sleep groups.

The study analyzed around 27,500 middle-aged and older adults from the UK Biobank, using MRI imaging and machine learning to estimate biological brain age based on over a thousand brain phenotypes.

Given that sleep habits are modifiable, improving sleep quality could serve as a practical strategy to delay brain aging and potentially prevent or slow cognitive decline associated with aging.

The study discusses mechanisms such as effects on the brain's waste clearance system during sleep and impacts on cardiovascular health, both of which can negatively influence brain aging.

The research was conducted in collaboration with international institutions including the Swedish School of Sport and Health Sciences, Tianjin Medical University, and Sichuan University.

Supported by organizations like the Alzheimer’s Foundation and Swedish Research Council, the study underscores the global importance of sleep health in maintaining cognitive and neurological integrity.

Limitations of the study include reliance on self-reported sleep data and the healthier profile of UK Biobank participants, which may affect the generalizability of the findings.