As someone for whom even 10 hours of sleep is often not enough, I have always been baffled by people who are perfectly happy sleeping for three to four hours every night and then spending the other 20 to 21 hours boosting professional and personal productivity. On three to four hours of sleep, I am living life like a zombie, perpetually fog-brained and dealing with screaming muscles. Self-help books and self-care routines will tell you eating better and exercising will help you maximize your active hours in the day, and you won’t need to sleep for as long. I’m relieved to relay scientists have found that being able to sleep for fewer hours and still function at 100% has nothing to do with lifestyle or determination, and everything to do with your genes.

Professors of neurology at the University of California, San Francisco, Ying-Hui Fu, Ph.D., and Dr. Louis Ptáček, MD, who have dedicated their careers to sleep genetics research, have found three of what they call short-sleep genes.

10 years ago, Fu identified the first short sleep gene that showed a person’s genetic makeup influenced their habitual sleep time, which in turn, also determined how they would respond to fluctuations in their average sleep time. She and her team found two people in a small family had a certain gene mutation called DEC2; these two were naturally short sleepers, i.e. their non-workday habitual sleep averaged 6.25 hours per night, as compared to those without the gene, whose non-workday habitual sleep averaged 8.06 hours per night. After Fu and team established the correlation between DEC2 and short sleep, they isolated the gene and created mice whose DNA contained an artificial clone of the human chromosome. They found the activity period for mice with DEC2 was longer than for those without, which led researchers to conclude the presence of DEC2 leads to an increase in wakefulness. Fu also found that this gene mutation is rare, and not all short sleepers had it — which led her to dedicate the next 10 years to discovering the second short sleep gene.

Back then, “People didn’t think that genes could significantly influence sleep behaviors, and big breakthroughs were rare. Today the field is advancing much more rapidly, and we’re beginning to get a better picture of how important your genes are to getting a good night’s sleep,” Fu said in a statement.

In August 2019, Fu published her second short-sleep discovery in Neuron, which showed another gene mutation, called ADRB1. Researchers found the ADRB1 gene was highly expressed in the part of the brain stem that regulated sleep. They found the neurons in which ADRB1 was expressed were easily triggered and played a major role in rousing the subjects of the experiment — mice. Fu and her team concluded that ADRB1 in its mutated form “helps build brains that are easier to rouse and that stay awake longer.”

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Going one step further, Fu and team published their discovery of a third short-sleep gene this month, in the journal Science Translational Medicine. They found the gene mutation NSPR1 encodes neurons involved in regulating sleep and is present in one in 4 million people. Fu and team found NSPR1 not only promotes wakefulness by affecting a single neuron but has the ability to activate other neighboring proteins that also work in increasing wakefulness.

The researchers then tested the effect of the gene mutation on the memory of mice. Researchers put mice in a special chamber and let them get acquainted with the environment, after which they sent an electric shock to the floor. When the mice returned one day later, they moved more consciously around the chamber and exhibited fear-based behaviors like freezing — but only if they had had sufficient sleep, in line with their habitual sleep time. The mice who were sleep-deprived did not remember their experience a day ago, as sleep deprivation causes memory deficits, for both mice and humans. Those with NSPR1, however, showed better memory, even without sleep deprivation.

This led Fu to confirm some findings about natural short sleepers she had been slowly accumulating — natural short sleepers, because of virtue of being able to function on less sleep, don’t face any of the negative consequences us mere mortals face from long-term lack of sleep, such as memory loss, “cardiovascular disease, cancer, dementia, metabolic problems and a weakened immune system,” Fu wrote in a statement. Fu and team also found natural short sleepers are innately “optimistic, more energetic and better multitaskers. They also have a higher pain threshold, don’t suffer from jet lag and some researchers believe they may even live longer.”

Turns out there is indeed some substance to the ‘early to bed and early to rise’ idiom drilled into most people’s brains by their grandmothers. Whether everybody has the ability in their DNA, however, remains to be seen.