Good sleep is critical to staying healthy
A study found that people in their 50s, 60s, and 70s that had less than 6 hours of sleep a night had a 30% greater chance of suffering from dementia later in life.
The study was conducted by Dr. Séverine Sabia and her team at the University of Paris. The study involved analyzing data from the Whitehall II study, which was conducted by the University College London.
The Whitehall II study started in 1985 and had 10,000 British participants. Their lifestyle and health were followed for 25 years.
8,000 of the participants either self-reported their sleep or wore tracking devices to record how well and how long they slept each night.
In the next 25 years, 521 participants, mostly in their late 70s, developed dementia.
Those participants that regularly got less than 6 hours of sleep a night were 30% more likely to get dementia than those that slept for 7 hours or longer.
The results of the study were reported in Nature Communications.
Known risk factors for developing dementia include smoking, drinking alcohol, and obesity. Another risk factor is age. Around 7% of over-60s are affected by dementia. This rises to around 16% for the over-80s.
What is dementia?
According to the National Institute on Aging, dementia is…
… the loss of cognitive functioning — thinking, remembering, and reasoning — to such an extent that it interferes with a person’s daily life and activities. Some people with dementia cannot control their emotions, and their personalities may change. Dementia ranges in severity from the mildest stage, when it is just beginning to affect a person’s functioning, to the most severe stage, when the person must depend completely on others for basic activities of living.
Dementia occurs when abnormal plaques and tangles of proteins build up in the brain. One of these types of protein is called amyloid-beta, which is considered to be a hallmark of Alzheimer’s.
Normally, the brain will clear these proteins each night when we sleep. This will mean that the proteins don’t build up in the brain.
It, therefore, makes sense that if we have poor-quality sleep these proteins won’t get cleared properly, resulting in a build-up in our brain.
What is not known though is whether less sleep or poor sleep causes this or whether the build-up of these proteins interferes with sleep. It may not be one or the other, but a combination of both, or something else entirely.
One theory is that bad sleep causes these proteins to build up, which in turn promotes bad sleep. Once this process starts it can become self-reinforcing.
A study reported in the European Heart Journal also showed how severe sleep disruption nearly doubled the risk of dying from heart disease for women. In men, the risk was increased by 25%.
This suggests that disrupted sleep over a long period of time negatively affects our health in various ways.
This seems to back up the case for poor sleep also leading to an increased risk of dementia.
Getting better sleep
To get good quality sleep we should be going to bed and getting up at the same time every day. We should also avoid excessive alcohol and caffeine, especially near bedtime.
We should also cut down on our usage of computers and smartphones a few hours before we go to bed.
A healthy diet and exercise can also promote good sleep.
Other ways to get a good night’s sleep are to make sure you have a comfortable bed, a noise-free environment, blackout blinds, and a cool room.
As coffee can lead to bad sleep, you may also be interested in this article about the dangers of coffee.