Dear A Moment of Science,
I know that when we get older we tend to get less sleep. Do scientists understand why?
Signed,
Sleepless in Fresno
Our Answer
According to research by scientists at the University of California, Berkeley, it's because aging makes the brain less able to initiate and sustain sleep.
The scientists looked at chemical signals important to the sleep process in young mice, and compared them to the same signals in older mice. They found that the mix of chemicals is the same in both young and old mice.
But the receptors in the brain that detect the chemical signals work better in younger mice than they do in older mice. In other words, as the mice age, their sleep chemical receptors decline.
Sleep Decline
The researchers suspect that the same decline is likely the case for humans, too. And it begins earlier than you might think: as early as a person's late 20s or early 30s.
By the time we turn 50, most people get only about half of the deep sleep they used to get when younger. And by age 70, most people get little to none of the deep sleep that's necessary for feeling really rested.
So, it seems possible that instead of aging causing us to sleep less, it may be the other way around. Getting less sleep is a factor in causing us to age.
There's currently no way to prevent the decline of aging sleep receptors in the brain. But the researchers hope their findings might lead to therapies to treat the problem.
Sources And Further Reading:
- Maldarelli, Claire. "We sleep less as we age because our brains don't think we're tired."Popular Science. April 5, 2017. Accessed June 22, 2017.
- Mander, Bryce A. et al. "Sleep And Human Aging." Neuron, Volume 94, Issue 1, 19-36. April 5, 2017. http://dx.doi.org/10.1016/j.neuron.2017.02.004 Accessed June 22, 2017.
