The researchers said that although the research, based on data from a long-term survey, could not prove cause and effect, it did draw a link between sleep and dementia as people age.
A study published Tuesday in the journal Nature Communications showed a higher risk of dementia in those who sleep six or less hours a night at the age of 50 or 60, compared to those who have a “normal” seven hours in bed.
There was also a 30 percent increased risk of dementia in people with consistently short sleep patterns between the ages of 50 and 70, regardless of cardiometabolic or mental problems, which are known risk factors for dementia.
The authors of the study from the French national health research institute INSERM analyzed the data of a long-term study from the University College London, which monitors the health of 7,959 British individuals since 1985.
Participants reported sleep duration on their own, while about 3,900 of them also wore watches overnight to confirm their estimates.
Nearly ten million new cases of dementia, including Alzheimer’s disease, are counted each year worldwide, according to the World Health Organization, and disturbed sleep is a common symptom.
But a growing body of research suggests that sleep patterns before the onset of dementia could also contribute to the development of the disease.
Sleep time is associated with a risk of dementia in older adults – 65 years and older – but it is unclear whether this association is also true for younger age groups, according to the authors.
They said future research might be able to determine if improving sleep patterns can help prevent dementia.
“Many of us have experienced poor night’s sleep and probably know that it can affect our memory and thinking in the short term, but the intriguing question is whether long-term sleep patterns can affect the risk of dementia,” said Sara Imarisio, Head of Research at Alzheimer’s Research UK he told the Science Media Center.
She said that although there is no magic bullet to prevent dementia, the evidence suggests that non-smoking, moderate drinking, mental and physical activity and eating well are among the things that can “help keep our brains healthy as we age”.