September 22, 2026, 6:05 pm | Read time: 3 minutes
Those who dream sufficiently may benefit more than previously thought. A new study involving nearly 100,000 people shows that more REM sleep–the sleep phase where most dreams occur–was associated with a lower risk of numerous diseases.
For the study, researchers from China analyzed data from 95,559 participants in the UK Biobank.1 The sleep data were not collected via questionnaires but through wrist-worn motion sensors. The scientists then observed the participants over an average (median) period of 8.9 years and evaluated which diseases newly appeared. Overall, the researchers examined the relationship between different sleep phases, sleep duration, and sleep regularity, as well as the risk for 1,049 diseases.
More REM Sleep, Lower Disease Risk
The most striking result: People with more REM sleep–the sleep phase where we dream particularly often and intensely–had a lower risk for a total of 83 diseases. These included heart failure, atrial fibrillation, dementia, Alzheimer’s, and Parkinson’s. More deep sleep was also associated with health benefits. Here, the researchers found links to a lower risk of type 2 diabetes, depression, sleep apnea, and Parkinson’s.
REM sleep is considered a particularly active sleep phase. During this time, the brain processes information, memories, and emotions. At the same time, important regeneration processes occur. The new study suggests that the amount of REM sleep could be an important marker for long-term health.
Sleep Duration Also Played a Role
The researchers also confirmed a known correlation: For most participants, a sleep duration of six to eight hours seemed to be associated with the lowest disease risk. Irregular sleep times, on the other hand, were more often linked to anxiety disorders and depression.
However, the authors emphasize that the study only shows associations. Whether more REM sleep actually protects against diseases or if healthier people inherently have more REM sleep cannot be determined from this.