Sleeping less than five hours a night linked to 37 diseases, study finds

Sleeping fewer than five hours a night was linked to a higher risk of 37 diseases, according to a major study that followed nearly 100,000 adults for almost nine years.

Researchers found that people who spent more time in rapid eye movement (REM) sleep had lower rates of several serious conditions, including dementia, heart failure and Parkinson’s disease.

For every additional 47.6 minutes of REM sleep, the observed rate of dementia was 46 per cent lower, heart failure 26 per cent lower and Parkinson’s disease 80 per cent lower.

The findings suggest that both sleep duration and the time spent in different sleep stages may be important indicators of long-term health.

The study analysed 95,559 UK Biobank participants who wore wrist-based activity trackers for seven consecutive days and nights. Researchers used a deep-learning algorithm to estimate sleep duration, sleep stages and night-time interruptions.

Over a median follow-up of 8.9 years, they identified 156 significant associations between sleep patterns and newly diagnosed diseases.

For 69 of 86 conditions linked to non-linear sleep-duration patterns, the lowest observed risk fell between six and eight hours a night.

More deep sleep was also associated with a lower risk of seven conditions, including type 2 diabetes and major depressive disorder.

Conversely, irregular sleep patterns and prolonged night-time awakenings were linked to higher risks of several conditions, including anxiety and substance use disorders.

ALSO READ: Deep pits, high costs forced Ondo coastal highway diversion — Umahi

REM sleep is associated with vivid dreaming, memory processing and emotional regulation, while deep sleep supports physical recovery.

The findings suggest that the relationship between sleep and health may extend beyond simply counting hours.

However, researchers caution that the study cannot prove that more REM sleep prevents disease or that short sleep directly causes it. Other health and lifestyle factors may help explain the associations.

The wearable devices also estimated sleep stages indirectly rather than measuring brain activity, as a clinical sleep study would.

The findings nevertheless reinforce the importance of getting sufficient, consistent sleep. Researchers say further studies are needed to determine whether improving sleep duration and quality can directly reduce the risk of serious diseases.