More time in dream sleep linked to lower risk of dozens of diseases

The study, published in PLOS Medicine, examined real-world sleep patterns and their relationship with more than 1,000 health outcomes.

Researchers analysed data from 95,559 UK Biobank participants who wore wrist accelerometers continuously for seven days and nights. Participants were then followed for a median of 8.9 years.

Using a deep-learning algorithm, researchers estimated participants’ REM, deep and light sleep, as well as total sleep duration, periods of wakefulness during the night and night-to-night sleep irregularity.

The researchers found that greater amounts of REM sleep were associated with a lower risk of 83 diseases. These included heart failure, dementia and Parkinson’s disease.

An increase of about 47.6 minutes in REM sleep, representing the interquartile range used in the analysis, was associated with a 26% lower risk of heart failure, a 46% lower risk of dementia and an 80% lower risk of Parkinson’s disease.

The study also found that greater amounts of deep sleep were associated with a lower risk of seven conditions, including type 2 diabetes and major depressive disorder.

Sleep consistency also appeared to matter. Greater night-to-night sleep irregularity and more time awake after initially falling asleep were associated with higher risks of several conditions, including anxiety and substance use disorders.

The researchers also found a non-linear relationship between total sleep duration and disease risk.

For many conditions, the lowest levels of risk were concentrated among people who slept between six and eight hours per night.

By comparison, people who slept for less than five hours had an increased risk associated with 37 conditions.

However, the researchers stressed that the findings show associations rather than proof of cause and effect.

Because the study was observational, it cannot establish that getting more REM or deep sleep directly prevents disease.

The study also relied on sleep measurements collected over seven days, meaning those measurements may not fully represent participants’ long-term sleep patterns.

The authors said the findings provide additional evidence that sleep duration and the distribution of different sleep stages may be important for health, particularly among middle-aged and older adults.

They identified 156 significant associations between sleep patterns and diseases after statistical correction, highlighting the broad relationship observed between sleep characteristics and long-term health outcomes.