"Our findings highlight the importance of addressing sleep problems earlier in life to preserve brain health, including maintaining a consistent sleep schedule, exercising, avoiding caffeine and alcohol before going to bed and using relaxation techniques," says Dr. Kristine Yaffe, a researcher at the University of California San Francisco and a member of the American Academy of Neurology. "Future research should focus on finding new ways to improve sleep quality and investigating the long-term impact of sleep on brain health in younger people."
This study looked at the relationship between poor sleep habits in middle age and brain aging later in life. The researchers used data from the Coronary Artery Risk Development in Young Adults (CARDIA) study, which has been following a group of people for many years.
At the start of the study, when participants were around 40 years old, they answered questions about their sleep habits. Things like whether they had trouble falling or staying asleep, if they woke up too early, and how long they slept each night. The researchers used this information to categorize participants as having 0-1, 2-3, or more than 3 poor sleep characteristics.
Around 15 years later, when the participants were in their mid-50s, they had brain MRI scans. The researchers used a machine learning technique to analyze the brain scans and determine each person's "brain age" - how old their brain appeared compared to their actual chronological age.
The study found that participants who reported more poor sleep characteristics in middle age (2-3 or more than 3) had older-appearing brains later in life, compared to those with 0-1 poor sleep characteristics. Specifically:
The researchers also looked at specific sleep problems like poor sleep quality, trouble falling or staying asleep, and waking up too early. They found these individual sleep issues were also linked to older-appearing brains, especially when the problems persisted over the 5-year period.
The study relied on self-reported sleep habits, which could be inaccurate. The brain age measurements, while effective, may still be influenced by other unmeasured factors. The sample, while diverse, may not fully represent the broader population. Additionally, this was an observational study, so it cannot prove that poor sleep directly causes faster brain aging.
The results suggest that poor sleep in middle age may contribute to accelerated brain aging, even before the development of major cognitive problems. This highlights the importance of addressing sleep issues early in adulthood, as they could have long-term impacts on brain health.
Interventions to improve sleep quality, rather than just focusing on sleep duration, may be an important target for preserving brain function as people get older. Further research is needed to fully understand the complex relationship between sleep and brain aging.
This research was funded in part by grants from the National Institutes of Health. The authors report no conflicts of interest related to the study.