← All articles
Sleep scienceCooling weighted blanketsingapore By JJ · 12 Oct 2026 · 5 min read

Does More REM Sleep Mean Fewer Diseases? 95,559 Adults Tracked

Short answer: in a UK study that tracked 95,559 adults for a median of 8.9 years, people who spent more time in estimated REM sleep were diagnosed with fewer of 83 different diseases, and sleeping under five hours was linked to the widest range of problems. It is an observational finding built on wrist-sensor estimates, so it shows a pattern worth respecting, not a switch you can flip. It also points to a very practical question: what is quietly stealing your REM on warm nights?

What the PLOS Medicine team did

The paper, published on 17 September 2026 in PLOS Medicine and widely covered in the past few days, used UK Biobank data. Participants wore a wrist accelerometer (a motion sensor) continuously for seven days. A deep-learning algorithm called SleepNet then estimated total sleep time, REM, deep sleep, light sleep, wakefulness after sleep onset (WASO) and how irregular sleep was from night to night. The researchers followed hospital records and tested links with 1,049 health outcomes.

The group was middle-aged and older: mean age 56.2, 43.7% male and 96.9% white. Median sleep was about 392 minutes a night (roughly 6.5 hours), and median REM was about 82 minutes.

The headline numbers, read carefully

Across the whole analysis there were 156 significant associations after a strict correction for running so many tests.

  • REM sleep: each interquartile-range increase in REM (47.6 minutes) was linked to lower risk of 83 diseases across 12 categories. Examples include heart failure (hazard ratio 0.74), dementias (0.54) and Alzheimer's disease (0.69).
  • Deep sleep: each 47.5 extra minutes was linked to lower risk of 7 diseases, including type 2 diabetes (0.89) and major depressive disorder (0.86).
  • Short sleep: people sleeping under five hours accounted for 37 of the 41 significant harmful associations compared with a 6 to 8 hour reference group. For people under six hours, heart failure carried a hazard ratio of 1.30.
  • Long sleep: sleeping more than eight hours was linked mainly to major depressive disorder (1.60), which can itself change how people sleep.

For 69 of the 86 conditions with a curved duration pattern, the lowest-risk point sat inside the 6 to 8 hour window. That lines up with earlier work: a 2010 meta-analysis of 16 prospective studies and more than 1.38 million people found higher death risk for both short sleepers (relative risk 1.12) and long sleepers (1.30), though sleep there was self-reported.

One headline detail needs a correction. Several news stories say REM was linked to an 80% lower rate of Parkinson's disease. In the paper, that figure belongs to parkinsonism (hazard ratio 0.20), and its confidence interval is wide, from 0.11 to 0.39. Treat it as a flag for follow-up, not a precise number.

Why you should not read this as "chase more REM"

The authors are clear about the limits, and they matter:

  1. Association, not cause. Early or hidden illness can disrupt sleep years before a diagnosis. After a two-year washout, only about 60% of the findings stayed significant.
  2. The sleep stages are estimates. SleepNet reads movement, not brain waves. Its REM, non-REM and wake classification scored an F1 of 0.49, which the authors call moderate. Against lab recordings it differed by about 48 minutes in total sleep time and about 17 minutes in REM.
  3. One week of data. A single week may not reflect your usual sleep, and outcomes came only from inpatient hospital records.

So the sturdiest message is the simplest one: regular sleep in the 6 to 8 hour range sits at the low-risk end of many outcomes, and consolidated sleep with less waking looks better than fragmented sleep.

Where heat enters the story

Your bedroom environment is one of the few things in this picture you can change. A review of how thermal environment affects sleep found that heat exposure increases wakefulness and decreases both REM and slow-wave sleep, and that humid heat adds further thermal load. For readers in Singapore or any warm, sticky city, that makes temperature worth taking seriously, even though the UK data cannot tell you how much REM a given hot night costs you.

A few sensible levers, none of them medical advice:

  1. Think about the sleep surface, not just the room. Lighter, breathable bedding gives heat somewhere to go, which matters more when the air is already warm and humid.
  2. Keep a consistent schedule. Greater night-to-night irregularity was linked to higher risk of three diseases in this study.
  3. Aim for the 6 to 8 hour window. It is where most of the lowest-risk points sat, and the AASM and Sleep Research Society recommend at least seven hours for healthy adults.
  4. If you use a weighted blanket in a warm climate, pick a cooling weighted blanket with breathable fabric, such as the phase-change knit design on the specifications page, so the calming pressure does not come with extra heat.

The bottom line

This study does not prove that REM prevents disease. It does add a large, objective, real-world dataset to a long line of evidence that 6 to 8 hours of steady sleep is a reasonable target and that very short sleep is the riskiest pattern. If your nights are short, hot or broken, that is worth fixing for its own sake, and worth raising with a doctor if it persists.

Sources

  • Luo J, Liu R, Yin J, Cao W, Sun S, Chen R. Accelerometer-derived real-world sleep stages and risk of incident diseases: A UK Biobank cohort study and phenome-wide association analysis. PLOS Medicine, 17 September 2026. https://doi.org/10.1371/journal.pmed.1005213
  • PLOS (via SciTechDaily). Sleeping Less Than 5 Hours Was Linked to Higher Risk of 37 Diseases. 11 October 2026. https://scitechdaily.com/sleeping-less-than-5-hours-was-linked-to-higher-risk-of-37-diseases/
  • Okamoto-Mizuno K, Mizuno K. Effects of thermal environment on sleep and circadian rhythm. Journal of Physiological Anthropology, 2012. https://pubmed.ncbi.nlm.nih.gov/22738673/
  • Cappuccio FP, D'Elia L, Strazzullo P, Miller MA. Sleep duration and all-cause mortality: a systematic review and meta-analysis of prospective studies. Sleep, 2010. https://pubmed.ncbi.nlm.nih.gov/20469800/
  • Watson NF, Badr MS, Belenky G, et al. Recommended Amount of Sleep for a Healthy Adult: A Joint Consensus Statement of the American Academy of Sleep Medicine and Sleep Research Society. Journal of Clinical Sleep Medicine, 2015. https://doi.org/10.5664/jcsm.4758

This article is informational and not medical advice. Claims about sleep and wellbeing are general; for personal health concerns consult a qualified professional.