What did the study find about REM sleep and disease risk?

The study found that greater amounts of REM sleep were associated with lower risks of 83 diseases, including heart failure, dementia, Parkinsonism and multiple sclerosis. However, the observational study could not prove that more REM sleep directly prevents these conditions.

How much REM sleep was linked to lower health risks?

For every additional 47.6 minutes of REM sleep, participants had lower risks across 83 diseases. Compared with people who had less REM sleep, those with more had a 26% lower risk of heart failure, a 46% lower risk of dementia and an 80% lower risk of Parkinsonism, based on the study\'s hazard ratios.

How many hours of sleep were generally associated with the lowest disease risk?

For 69 disease outcomes, the sleep duration associated with the lowest risk was generally between six and eight hours a night. The study found that people sleeping for less than five hours had increased risk associated with 37 conditions, but it also noted that individual sleep needs vary.

Can getting more REM sleep prevent disease?

The study does not show that more REM sleep prevents disease. Because it was observational, it identified associations between sleep patterns and later health outcomes but could not establish cause and effect. An underlying health condition may also affect sleep.

Getting More REM Sleep Could Lower Your Risk of 83 Diseases, Study Finds

Q: Was deep sleep also linked to better health?

Yes. Greater amounts of deep sleep were associated with lower risks of seven conditions, including type 2 diabetes, major depressive disorder, sleep apnoea and Parkinson\'s disease. An additional 47.5 minutes of deep sleep was associated with an 11% lower risk of type 2 diabetes.

Getting enough sleep may be about more than simply counting the hours you spend in bed. New research suggests that the amount of time you spend in different sleep stages could also be linked to your long-term health.

A study of 95,559 UK adults found that greater amounts of rapid eye movement (REM) sleep were associated with a lower risk of 83 diseases, including heart failure, atrial fibrillation, dementia, Parkinsonism and multiple sclerosis.

The findings, published in PLOS Medicine, add to growing evidence that sleep quality and structure may be just as important as sleep duration.

More REM Sleep, Lower Disease Risk

Researchers from Peking University analysed UK Biobank data from adults who wore wrist accelerometers for seven consecutive days and nights. Using a deep-learning algorithm, they estimated how much time participants spent in REM, deep and light sleep.

The participants were then followed for a median of 8.9 years, with researchers examining health records covering 1,049 disease outcomes.

For every additional 47.6 minutes of REM sleep, participants had lower risks of 83 diseases across 12 categories.

Some of the strongest associations were seen for heart failure, dementia and Parkinsonism. Compared with people with less REM sleep, those with more had a 26% lower risk of heart failure, a 46% lower risk of dementia and an 80% lower risk of Parkinsonism, based on the study's hazard ratios.

Deep Sleep Was Linked to Other Benefits

REM sleep was not the only stage associated with health. Greater amounts of deep sleep were associated with lower risks of seven conditions, including type 2 diabetes, major depressive disorder, sleep apnoea and Parkinson's disease. An additional 47.5 minutes of deep sleep was associated with an 11% lower risk of type 2 diabetes.

The researchers also found that more light sleep was associated with higher risks of several conditions, including major depressive disorder, although it was linked to lower risks of some others.

How Much Sleep Is Enough?

The study also looked at total sleep duration and found that the relationship between sleep and disease was not simply a case of 'more is better'.

For 69 disease outcomes, the sleep duration associated with the lowest risk was generally concentrated between six and eight hours a night. People sleeping for less than five hours had the highest clinical vulnerability, with increased risk associated with 37 conditions.

However, this does not mean everyone should try to force themselves into a particular sleep duration. Individual sleep needs vary, and sleep quality, regularity, and underlying health conditions can all affect how someone sleeps.

Can More REM Sleep Prevent Disease?

Not necessarily. The study was observational, meaning it identified relationships between sleep patterns and later disease but cannot prove that getting more REM sleep directly prevents illness.

The researchers also acknowledged the possibility of reverse causation, where an underlying condition affects sleep rather than poor sleep causing the condition.

For example, depression can disrupt sleep, making it difficult to determine whether altered sleep contributes to depression or whether depression changes sleep patterns.

Still, the findings reinforce the importance of protecting sleep as part of overall health. Maintaining a consistent sleep schedule, allowing enough time for sleep, and addressing persistent sleep problems may be more useful than focusing solely on a sleep-tracker score or trying to artificially increase one particular sleep stage.

REM sleep may be only one piece of the puzzle, but the study suggests that how we sleep could matter almost as much as how long we sleep.