According to a new longitudinal study of almost 8,000 British adults followed for more than 25 years, sleeping six hours or less a night between the ages of 50 and 60 is associated with an increased risk of dementia .
There was also a 30 percent increased risk of dementia in those with consistently short sleep patterns from the age of 50 to 70, regardless of cardiometabolic or mental health problems, which are known risk factors for dementia .
Correlation, not causality
The study authors from the French national institute for health research INSERM analyzed data from a long-term study conducted by University College London, which has followed the health of 7,959 British individuals since 1985 .
The participants reported their sleep duration themselves, while around 3,900 of them also wore watch devices at night to confirm their estimates.
However, as the researchers themselves clarify, we are facing a correlation, not a causality .
Also, while time spent sleeping is related to dementia risk in older adults, 65 and older, it is unclear whether this association is also true for younger age groups.