The Relationship Between Sleep and Dementia

Did you know that Singaporeans have been cited as being amongst the most sleep deprived globally?

While the National Sleep Foundation recommends at least seven hours of sleep each night, YouGov’s latest survey reveals only one in four people in Singapore (27%) have an ideal sleep cycle (of 7 hours or more).

Does poor sleep cause dementia?

In a long-term study, Harvard Medical School followed 2,800 individuals ages 65 and older. Researchers found that individuals who slept under five hours per night were twice as likely to develop dementia compared to those who slept six to eight hours per night. A different study of nearly 8,000 participants found a 30% increase in dementia risk was associated with sleeping six hours or less at age 50, 60 and 70, compared to a normal sleep duration of seven hours.

How does dementia affect sleep?

While poor and insufficient sleep can be risk factors of dementia, sleep problems are also a known symptom of having dementia. Healthy brain function requires healthy sleep, which means our bodies must cycle through the various sleep stages.

Throughout the night a person can go through four to six sleep cycles that vary in length. During stages 3 and 4, the body restores itself, making these stages essential for cognitive function and overall health. People with dementia spend less time in the later stages of sleep and more time in the earlier stages, which can also worsen as dementia progresses.

Additionally, dementia changes the body’s natural sleep-wake cycle, or circadian rhythm. Individuals who have Alzheimer’s disease often have damaged cells in the brain’s suprachiasmatic nucleus (SCN) and lower cellular activity. Because of this dysfunction, patients are often unable to follow a 24-hour sleep-wake cycle and instead sleep more during the day and less at night.

Tips for Restful Sleep

Maintaining deep and restful sleep is important for overall brain health and may help reduce the risk of dementia as we age.

Maintain a regular sleep schedule

Create a bedtime routine and try to head to bed and wake up at the same time each time–even on weekends.

Avoid caffeinated drinks at night

Switch out caffeinated drinks like coffee and black tea for alternatives with less caffeine, like white tea, decaf or water, at least 8 hours before you plan to go to bed.

Keep the bedroom dark

Close the curtains and turn off the lights to reduce light and noise.

Exercise regularly

Try to exercise regularly throughout the week, but avoid exercising too closely before going to bed.

Avoid screens an hour before bedtime

Artificial light from electronics emits blue light which delays the release of melatonin, a key hormone that signals tiredness to the brain. This can make it harder to fall asleep.

Take sleep-promoting supplements

Ashwagandha, saffron, or melatonin supplement can help in promoting relaxation and happy mood, improving sleep quality and let your mind & body to have enough rest.