Sleeping six hours or less per night in your 50s and 70s is associated with an increased risk of dementia, according to a new study of nearly 8,000 British adults followed for more than 25 years.
The study, published in the journal Nature Communications, showed a 20 to 40 percent higher risk of dementia in those sleeping six or fewer hours per night at the ages of 50 or 60, compared to those who have a "normal" seven hours in bed, according to AFP.
The study carried out by the French national health-research institute INSERM in collaboration with the University College London, could not prove cause and effect, but it did draw a link between sleep and dementia.
Researcher Séverine Sabia and her colleagues noted that there was a 30 percent increased dementia risk in those with consistently short sleeping patterns from the age of 50 to 70, irrespective of cardiometabolic or mental health issues, which are known risk factors for dementia.
The participants self-examined their sleep six times between 1985 and 2015. In 2012, around 3,900 of them used a watch-like device that monitors motions during night sleep to verify their estimates. The results of the examination confirmed the findings on the dementia risk.
Over 10 million new dementia cases, including Alzheimer's, are registered annually, according to the World Health Organization (WHO). Dementia patients often experience sleep disorders, but growing research evidence suggests that sleep patterns before dementia could contribute to the development of the disease.
INSERM said these findings show that sleep in middle age could play a key role in the brain health, which underscores the importance of adopting healthy sleep habits. According to the journal Nature, future research may be able to determine whether improving sleep patterns can help prevent dementia.
"Quitting smoking, drinking in moderation, staying mentally and physically active eating well, and maintaining healthy cholesterol levels and blood pressure, all are factors that can help keep our brains healthy as we age," said Sara Imarisio, from the Alzheimer's Research Fund.
