Most adults need between seven and nine hours of sleep a night to stay healthy, but research has shown that some people can survive on much less without suffering any harm to their health.
Dr. Ying-Hui Fu, professor of neurology and a pioneer in sleep and genetics research at the University of California San Francisco, has identified a number of gene mutations that control how much sleep people need.
Her research found that people she referred to as “natural short sleepers” benefit from a gene mutation that allows them to lead healthy lives even though they only need four to six hours of sleep a night.
Professor Fu told Sunday Morning the mutations were new from an evolutionary point of view and likely a response to fairly new technological innovations.
“Our sleep behavior has changed significantly with the light bulb and electricity, which has allowed us to stay awake much longer,” she said.
“In front [those inventions] There was no benefit in staying up late. “
Natural short sleepers are “quite rare,” said Fu.
They tended to be active and healthy and did not rely on coffee or other external stimulants to keep them awake despite their reduced sleep times.
“After what we have observed over the past 15 years, [natural short-sleepers] seem to be staying very healthy. “
Fu’s research included manipulating the genes of mice to reflect the mutation in the hibernation gene that she had identified in humans.
“It takes about a year or two to make a mouse model that carries exactly the same mutation as a human,” she said.
When this was achieved, however, she was able to show that the mutated mice showed the same short sleep behavior as humans with the same mutation.
This modeling also revealed other possible effects of the mutation that human participants alluded to in their study, including a superior ability to remember things.
“Some of them (the short sleepers) will tell me that they have these really amazing memories … they can speak many languages or they hear something and never forget it,” said Fu.
“What we found is that in normal mice, like normal humans, we don’t remember what we learned during the day, if we don’t sleep well that night, and if we just sleep well. .
“We found these mutant mice … we can deprive them of sleep and they still remember everything very well, whereas the normal mice … if you deprive them of sleep, they don’t remember anything they learned the day before. “
A second group that Fu’s research identified were people who slept less than the recommended amount of time but who did not have the natural short sleeper mutation.
These “habitual short sleepers” were people who had taught themselves to survive with less sleep, but Fu warned that their actions were detrimental to their health.
“If I needed eight to eight and a half hours of sleep and I was just trying to get six hours of sleep … very quickly, I’d be working at 70 percent … at best of my capacity.”
“I can live like this for years, but it really doesn’t do me any good … the problem is, most people don’t realize it.”
Fu admitted that there were benefits to being able to survive in the digital age with fewer hours of sleep, and said it was likely that more people would eventually become natural short sleepers.
In the meantime, your goal is to understand how and why the short sleeper mutation allows its owners to sleep more efficiently.
“When we sleep, our body is actually very busy doing all kinds of things … be it getting more energy for the next day or removing toxins that we are building up in our bodies … all of that must be our bodies do while we sleep and for us it takes eight hours but for [natural short-sleepers] it takes four to six hours. “
“We’re trying to find out how it works; how their sleep is more efficient, so that we can help everyone sleep more efficiently.”