Research over the years has shown the importance of sleep to both physical and mental wellbeing. But a new study shines a light specifically on how lack of sleep in middle age may lead to developing dementia later in life.
The study’s findings add to recent research that has shown the importance of sleep to brain health as you age. Using data from thousands of patients, researchers found that those who did not get a normal night of sleep regularly in their 50s and 60s had a higher risk of developing dementia in their 70s.
It’s a finding that study authors hope will get the attention of health officials. “Public health messages to encourage good sleep hygiene may be particularly important for people at a higher risk of dementia,” the authors wrote in the study, published in the journal Nature Communications.
The Study Involved Almost 8,000 Patients in the United Kingdom
The study involved a large cohort of 7,959 people, all of them living in the United Kingdom. The study used data from the patients that spanned 25 years and started when they turned 50.
The data came from Whitehall II, a study of British civil servants that ran from 1985 to 2016. For the current study, researchers pulled information from Whitehall II on the number of hours study participants slept each night, as well as other health issues. By the end of the study, 521 of the participants were diagnosed with dementia at an average age of 77.
The study defined normal sleep as at least seven hours a night. Researchers found that among the thousands of people in the study, those who slept six hours or less on average weeknights were 30% more likely to later develop dementia than those who had normal sleep patterns.
While the difference is just one hour a night of sleep on average, the impact on the brain apparently accumulates over time.
“It would be really unlikely that almost three decades earlier, this sleep was a symptom of dementia, so it’s a great study in providing strong evidence that sleep is really a risk factor,” Dr. Kristine Yaffe, a professor of neurology and psychiatry at the University of California, San Francisco, who was not involved in the study, told the New York Times.
The Chicken or the Egg Debate
One caveat to the research is that scientists already know that the protein tangles that are a sign of Alzheimer’s disease start to form 10 to 15 years before the onset of the disease. In light of that, it’s possible that the lack of sleep is an effect of the emerging dementia. This is a “chicken or the egg” debate that has come up before: does dementia cause lack of sleep, or does lack of sleep cause dementia.
However, scientists interviewed by the Times said the new study, while not conclusive on the issue, does a good job of making a connection between lack of sleep and later development of dementia. That’s because the study started when the participants were 50, making the presence of protein tangles less likely in most cases. It’s also important to consider that the dementia diagnosis did not happen until the patients were 77 years old on average.
While more research is expected on the issue, the study’s findings illustrate why getting a good night’s sleep is a priority for those in their 50s and 60s. Some of the tips for getting a good night’s sleep include:
- Going to bed at a consistent time every night
- Avoiding large meals in the few hours before bedtime, as well as caffeine and alcohol
- Engaging in physical activity during the day
- Avoid taking long naps
- Avoiding looking at your phone, watching television or working on a computer late at night
Developing better sleep practices on your own gives you a better night’s sleep than using medication. However, those with sleep disorders or apnea will benefit from seeing a sleep specialist.