The correlation also determined whether or not people used sleeping pills and whether they had a mutation called ApoE4 that made people more likely to develop Alzheimer’s, Dr. Sabia said.
“The study has a modest but I would say an important link between short-term sleep and dementia risk,” said Pamela Lutsey, an associate professor of epidemiology and community health at the University of Minnesota who was not involved in the research. not. ‘Short sleep is very common, and even if it is modestly associated with dementia, it can be important on a social level. Short sleep is something we have control over, something you can change. ”
However, the study, as with other research in this area, has limitations that prevent it from proving that insufficient sleep can cause dementia. Experts believe that most of the sleep data was self-reported, a subjective measure that is not always accurate.
At one point, nearly 4,000 participants did have the sleep duration using accelerometers, and that the data were consistent with their self-reported sleep times, the researchers said. However, this quantitative measure came late in the study, when participants were about 69, which made it less useful than when obtained at younger ages.
In addition, most participants were white and better educated and healthier than the British population. And if they relied on electronic medical records for dementia diagnoses, researchers would have missed some cases. They also could not identify exact types of dementia.
“It is always difficult to know what conclusions can be drawn from these types of studies,” wrote Robert Howard, a professor of geriatric psychiatry at University College London, one of several experts who commented on the study to Nature Communications. has. “Insomnia – which probably does not need anything else to chew over in bed,” he adds, “should not worry that they are on their way to dementia unless they sleep immediately.”
There are compelling scientific theories as to why too little sleep can exacerbate the risk of dementia, especially Alzheimer’s. Studies have found that the cerebrospinal fluid levels of amyloid, a protein that collects in plaques in Alzheimer’s, “rise when your people are not sleeping,” said Dr. Music said. Other studies on amyloid and another Alzheimer’s protein, tau, suggest that ‘sleep is important in removing proteins from the brain or limiting production,’ he said.