A team of neurologists from the University of California, San Francisco, analyzed sleep quality and cognitive abilities in about 600 individuals, with an average age of 40. The findings revealed that poor sleep in this age group is “associated with nearly three years of additional brain aging,” reported lead author Clemence Kavaies.
This result remains consistent even after accounting for factors such as gender, high blood pressure, and diabetes.
Poor sleep primarily refers to difficulties in falling asleep and maintaining sleep, the researchers explained.
What Did the Scientists Discover?
At the beginning of the study and five years later, around six hundred volunteers completed a questionnaire regarding their nighttime sleep. Fifteen years into the study, participants underwent brain scans. The research team aimed to determine how the structure of their brains had changed, as reported by the Independent.
The questionnaire focused on six key characteristics of poor sleep, including short sleep duration, poor sleep quality, difficulties falling asleep, difficulties maintaining sleep, early awakening, and daytime sleepiness.
Participants were divided into three groups. The first group (with low levels of poor sleep) included those who reported experiencing no more than one of these factors. The second group (with moderate levels) consisted of those who identified two to three of these characteristics. The third group (with high levels) included those who reported more than three characteristics.
The results showed that individuals in the second group had an average brain age that was 1.6 years older than those in the first group. Meanwhile, participants in the third group had an average brain age that was 2.6 years older than those in the first group.
“Previous studies have linked sleep problems to poor thinking and memory in older age, increasing the risk of developing dementia. Our study, which used brain scans to determine participants’ brain age, confirmed that poor sleep is associated with nearly three years of additional brain aging even in middle age,” noted Dr. Clemence Kavaies.
Her colleague, Christine Yaffe, added, “Our results emphasize the importance of addressing sleep issues early in life to maintain brain health.” She believes that special attention should be given to sleep routines, physical activity, and relaxation techniques. It is also crucial to avoid caffeine and alcohol before bedtime.
“Future research should focus on finding new methods to improve sleep and studying its long-term effects on the brain health of young people,” Ms. Yaffe stated.
The study’s findings were published in the journal Neurology of the American Academy of Neurology.
What Do Other Scientists Think?
Meanwhile, authors of another study from Yale University (USA), also published in this journal, assert that high-quality sleep, along with physical activity, healthy eating, and smoking cessation, helps reduce the risk of stroke, dementia, and depression in older age. These results are based on data from over 316,000 adults stored in the UK Biobank, which contains health and lifestyle information on more than half a million Britons.
According to the authors, maintaining four key indicators—body weight, cholesterol levels, blood pressure, and blood sugar—within a healthy range is crucial for overall brain health.