There’s sleep. And then there’s sleep.
After head meets pillow, the kind of slumber we experience as the clock ticks away the seconds until the alarm sounds differ and are divided into four stages. All are crucial to good health, allowing time for our brain and body to repair itself.
The time when your most vivid dreams occur, for example, is rapid-eye-movement, or REM [rhymes with gem], sleep. It’s our last cycle of sleep.
But it’s deep, or slow-wave sleep — the third phase of sleep — that is probably most important in maintaining good brain function and memory.
A recent study by Australian researchers shows how deep sleep can have an oversized impact on our brains: Reducing this stage by even 1% heightens the risk of dementia by 27% in those age 60 or older.
The investigation included nearly 350 people in this age group who completed two sleep studies, each separated by an average of five years. The first studies began in 1995. After participants completed the second, they were then monitored for about 17 years.
The higher dementia risk is striking. And researchers say the work shows how important deep sleep is to healthy aging.
Our breathing and brain waves slow down during deep sleep. A hormone is released that allows the body’s tissues to heal. All of this helps us feel rested when we wake.
The risk of dementia, however, is reversible.
Achieving a deeper sleep involves developing good bedtime habits. Those include limiting caffeine and alcohol, eating healthy foods, exercising and avoiding light disturbances.
While duration of sleep is important, quality sleep is the goal.
There’s no need to go full Rip Van Winkle.