Getting greater amounts of rapid eye movement sleep is associated with a reduced risk of developing dozens of medical conditions, including dementia, Parkinson’s disease and heart failure, according to a large study published Sept. 17 in the journal PLOS Medicine.
Researchers in China evaluated health metrics from 95,559 participants in the UK Biobank who wore wrist accelerometers around the clock for seven straight days between 2013 and 2015, Fox News and Yahoo Health reported. Using an algorithm called SleepNet to evaluate movement records, scientists estimated time spent in rapid eye movement, or REM, slumber alongside deep and light sleep stages, following participants for a median follow-up window of nearly nine years.
Across more than 1,000 examined health outcomes, higher amounts of REM sleep were linked to lower chances of developing 83 conditions, the researchers reported. Specifically, greater REM sleep corresponded with an 80 percent lower relative risk of Parkinson’s disease, a 46 percent lower risk of dementia and a 26 percent lower risk of heart failure, according to Fox News.
The role of deep sleep and overall duration
The investigation also discovered that deeper stages of rest correlated with reduced vulnerability to seven ailments, including Type 2 diabetes and major depressive disorder, Diabetes.co.uk reported. In total, researchers identified 156 distinct links connecting nightly slumber patterns to future diagnoses.
Overall sleep duration appeared equally significant. The study identified six to eight hours per evening as the optimal duration associated with minimal danger for 69 health conditions. In contrast, resting fewer than five hours nightly was tied to elevated risk across 37 medical problems. Participants experiencing inconsistent nightly schedules and frequent awakenings were also found to face heightened risks for anxiety and substance use disorders, according to Fox News.
Separate research from York University in Canada examining pooled data from nearly 4.5 million people in PLOS One similarly pinpointed seven to eight hours nightly as the ideal window for lowering dementia danger, ScienceAlert reported.
Observational limits and expert reaction
Sleep specialists noted that the findings do not establish that changing sleep cycles directly prevents chronic illness. Because the study was observational, it cannot prove cause and effect.
“At the same time, poor sleep may contribute to disease progression, so the relationship likely works both ways,” Dr. Chelsie Rohrscheib, a sleep expert at Wesper, told Fox News Digital, noting that conditions such as Parkinson’s can disrupt slumber years before diagnosis.
Independent researchers also warned against overinterpreting wearable gadget data. Dr. Michael A. Grandner of the University of Arizona told Yahoo Health that wristbands register physical motion rather than brain electrical activity, meaning algorithmic stage classifications carry notable uncertainty. He added that people should not view any single phase as uniquely therapeutic, because healthy rest requires cycling through all phases as part of a coordinated biological process.
Dr. Oki Ishikawa of Northwell’s Northern Westchester Hospital told Fox News that REM typically comprises 20 to 25 percent of a normal cycle, adding that obtaining sufficient uninterrupted sleep remains the primary goal.
What patients can do
Medical experts continue to recommend established behavioral habits to improve slumber quality, including:
- Maintaining consistent wake and bed times every day.
- Keeping bedrooms quiet, dark and cool.
- Limiting alcohol, caffeine and heavy meals close to bedtime.
- Seeking clinical evaluation for symptoms like chronic exhaustion or suspected sleep apnea.
Researchers noted that further clinical investigations are required to discover whether intervening directly to prolong REM or slow-wave stages can help avert chronic diseases.
