There is so much we can do from a lifestyle perspective to help safeguard our brains against declining function. And certainly getting a good night’s sleep is one of the most important choices a person can make to help preserve and protect this vital organ. In October 2020, I wrote a piece on the relationship between sleep duration and cognitive decline, and it was based on a very large study performed in England. This study demonstrated that there was risk for cognitive decline with not enough sleep as well as too much sleep. And it concluded that between 7 to 8 hours of sleep each night is the “sweet spot” in terms of being related to the least risk for cognitive decline.
This week, a new study published in the journal Nature Communications entitled “Association of sleep duration in middle and old age with incidence of dementia” reviewed data from close to 8,000 participants over a 25-year period of time. They demonstrated that there was higher risk for developing dementia with sleep duration of six hours or less at specific ages of 50, 60, and 70 years. The findings of the study showed the risk for actually developing dementia was increased by 30% in all three age categories. To be sure, these findings were independent of sociodemographic, behavioral, cardiometabolic, and mental health factors.
Interestingly, in contrast to the study I quoted last year, these researchers did not find strong evidence that longer sleep duration is associated with dementia risk. In fact, there were very few individuals in the study who actually experienced long sleep duration so this was difficult to evaluate. Continue reading