Which kind of sleep reduces the risk of dementia by 46%? 95,000 people study to reveal key to brain protection

2026/10/14 11:33

Sleep quality not only depends on the duration, but the rapid eye movement period may also be related to the risk of diseases such as dementia and Parkinson's disease; situational photo. (Picture taken from Freepik)

[Compiled by Chen Chengliang/Comprehensive Report] Sleep is not only about the length of time, but also the structural stages experienced during sleep, which may have a profound impact on long-term health. A large medical study covering 95,559 adults found that those who slept longer in the rapid eye movement (REM) period were significantly associated with a lower risk of 83 diseases, including dementia, Parkinson's disease and heart failure. However, the research team emphasized that this result is an observational study and does not prove that extending REM sleep can directly prevent diseases.

According to Fox News Digital, this study was published in the medical journal "PLOS Medicine" on September 17. The research team analyzed data from participants in the UK Biobank. Participants wore wrist accelerometers for 7 consecutive days. The researchers used deep learning algorithms to analyze sleep stages and regularity, and tracked health records for a median of 8.9 years to evaluate the correlation between sleep indicators and 1,049 health outcomes.

Please read on...

The findings showed that sleeping longer each night during REM was associated with an estimated 80% lower risk of Parkinson's disease, a 46% lower risk of dementia and a 26% lower risk of heart failure during the follow-up period. Longer deep sleep is associated with a lower risk of seven diseases, including type 2 diabetes and major depression. However, research points out that the range of health benefits corresponding to the two sleep stages is different, and it cannot be directly determined that the rapid eye movement period is more important than deep sleep.

The risk of getting sick is lowest between 6 and 8 hours a night

In terms of total hours of sleep, the study found that those who slept 6 to 8 hours a night were associated with the lowest risk of 69 diseases; in contrast, those who slept less than 5 hours a night were associated with an increased risk of 37 diseases. In addition, poor sleep regularity and frequent awakening after falling asleep are also related to increased risks of mental illness and anxiety.

External medical experts who were not involved in the study reminded that pathological changes in the brain may begin to interfere with the sleep mechanism years before clinical diagnosis of neurodegenerative diseases or heart failure. Therefore, abnormal sleep is not necessarily the cause of the disease, but may be a hidden warning in the early stages of the disease. There may be a two-way interaction between the two.

The research team added that the accuracy of wrist-based devices in interpreting sleep stages is still lower than that of multiple clinical sleep physiology examinations, and the subjects are mostly from a single database in the UK, so the conclusions may not be directly applicable to all ethnic groups. The study mainly provides a reference for preventive medicine. If people face severe sleep disorders or persistent daytime sleepiness for a long time, they should still seek clinical evaluation from a professional medical team.