A study from the University of Arizona indicates that certain sleep habits may be linked to signs of brain aging. Published in the journal Alzheimer's & Dementia, the research analyzed brain scans and questionnaire data from over 23,000 middle-aged and older adults in a biomedical database. The study is part of a collaborative effort involving the university's Department of Psychology, the Zuckerman College of Public Health, and the University of Southern California.
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Researchers identified three sleep behaviors associated with brain aging markers in healthy individuals: sleeping less than the recommended seven to nine hours, frequent daytime napping, and sleeplessness. These behaviors were linked to an increased volume of white matter lesions—areas of brain damage that can accumulate with age and are associated with a higher risk of dementia, including Alzheimer's disease.
Madeline Ally, the study's lead author and a graduate researcher at the Department of Psychology, noted that sleep should be examined as a collection of distinct patterns rather than a single measure. She emphasized the complexity of sleep and the need for more research on how specific sleep behaviors relate to brain health.
Participants provided baseline information from 2006 to 2010 on five sleep behaviors: sleep duration, daytime napping, sleeplessness, unintentional daytime dozing, and snoring. Approximately nine years later, they underwent brain MRI scans to measure white matter lesion volumes. Initially, all five sleep behaviors were associated with larger lesion volumes, but after adjusting for factors such as blood vessel health and lifestyle issues—like high blood pressure and smoking—only the three behaviors remained significant.
Interestingly, the study found that while napping may have benefits for alertness and cognition, the questionnaire did not capture specifics about nap length or timing. Gene Alexander, the senior author and a professor in the Department of Psychology, indicated that future research should investigate the differing impacts of short versus long naps on brain health over time.
Further analysis revealed that participants who slept fewer than seven hours per night had increased lesion volumes compared to those within the recommended range. Alexander remarked that insufficient sleep could contribute to greater white matter lesion volumes as people age. However, no similar effects were observed in those reporting longer sleep durations, warranting further investigation.
Alexander highlighted that the studied behaviors are modifiable risk factors. Improving sleep quality may diminish the effects of brain aging and potentially lower dementia risks, including Alzheimer's disease.