Getting quality shuteye may do more than leave you feeling refreshed. New research suggests deep, slow-wave sleep could be vital for preventing cognitive decline.
The findings suggest deep sleep is a potential modifiable factor for lowering dementia risk in aging populations.
Catch up quick: Slow-wave sleep (or deep sleep) is our deepest sleep stage and allows the brain to clear away waste. This may help prevent proteins that accumulate in Alzheimer's.
- Slow-wave sleep lasts about 87 minutes and occurs during the first hours of the night.
- It makes you feel refreshed when you wake up.
- The body repairs muscles, bones, and soft tissues and strengthens the immune system during slow-wave sleep.
“Slow-wave sleep, or deep sleep, supports the aging brain in many ways, and we know that sleep augments the clearance of metabolic waste from the brain, including facilitating the clearance of proteins that aggregate in Alzheimer’s disease. However, to date we have been unsure of the role of slow-wave sleep in the development of dementia. Our findings suggest that slow-wave sleep loss may be a modifiable dementia risk factor.” —Professor Matthew Pase, Monash University School of Psychological Sciences, Melbourne, Australia
Why it matters
As deep sleep often diminishes with age, preserving it could be a promising way for older adults to reduce dementia risk.
1 big idea: A healthy diet, regular exercise, healthy hearing, and high-quality sleep are investments that lower the risk of dementia.
A closer look
- The study examined 346 people over 60 who did two sleep studies five years apart.
- The researchers followed the participants up to 17 years to determine who developed dementia.
- A 1% yearly decline in slow-wave sleep resulted in a 27% higher dementia risk over time, independent of other factors.
Relevant: Those linked genetically to Alzheimer's risk had faster drops in slow-wave sleep, strengthening the biological connection between deep sleep and developing dementia.
What's next: Scientists want to study the connection between sleep stages and dementia.
Good news
You can improve the quality of your sleep by taking small, proven steps. Here are five:
- Stick to a sleep schedule: Go to bed and wake up at the same time every day, even on weekends.
- Block out light: Excess light exposure throws off your sleep and circadian rhythms. Blackout curtains or a sleep mask prevent light from disrupting your rest. Avoiding bright light also helps you transition to bedtime and promotes the production of melatonin, a hormone that promotes sleep.
- Minimize noise: Keeping noise to a minimum is essential to building a sleep-friendly bedroom. If you cannot eliminate nearby noise sources, consider drowning them with a fan or white noise machine.
- Pay attention to what you eat and drink: Avoid large meals, caffeine, and alcohol before bedtime. Focus on a heart-healthy diet rich in vegetables, fruit, healthy fats, and limited red meat.
- Include physical activity: Being physically active during the day can help you fall asleep more easily at night. However, avoid exercising too close to bedtime, which can interfere with sleep.
