The figures associated with Alzheimer’s disease do not stop growing around the world and the future does not seem very promising. Now, a study suggests there may be a link between sleeping a lot and the risk of developing dementia.
The research, led by Sudha Seshadri, a professor of neurology at Boston University School of Medicine (USA) examined data from the Framingham Heart Study , a large cohort study that began in 1948 with 5,209 men and women from between 30 and 62 years who lived in the city of Framingham, Massachusetts. The original purpose of the study was to identify risk factors for cardiovascular disease.
For this experiment, the researchers asked participants how long they slept each night, conducting a 10-year clinical follow-up to see who eventually developed Alzheimer’s disease and other forms of dementia . Using the data on sleep duration, the experts calculated the risk of dementia.
The data is stark: sleeping 9 hours a day or more is twice as likely to develop Alzheimer’s in 10 years , compared to those who usually sleep less than 9 hours.
Education also counts
“Participants without a high school degree who slept more than 9 hours each night had six times the risk of developing dementia in 10 years compared to participants who slept less. These results suggest that having a higher education may protect against dementia in relation to a long duration of sleep, “says Seshadri.
The researchers also found that people who slept longer hours each night appeared to have smaller brain volumes, so they suspect that excessive sleep is likely a symptom rather than a cause of the neural changes that occur with dementia. As a consequence, they speculate that reducing the duration of sleep does not have to reduce the risk of dementia.
The study has been published in the journal Neurology.
