A quarter of UK adults fall short of NHS sleep recommendations, while a small group of people thrive on just four hours nightly due to a rare genetic condition. Researchers are studying these natural short sleepers to uncover how genetic mutations might protect carriers from long-term neurological and health consequences.
While millions struggle to log a full night of rest, a distinct subset of the population operates smoothly on a fraction of that time. Aimee Pugh Bernard, an immunology professor at the University of Colorado, typically goes to bed around 22:00 and wakes up at 04:30. I’m wide awake. I cannot stay in bed,
she says. Bernard often logs only five hours of slumber, yet she routinely walks her dog, completes a one-hour gym session, and finishes an hour and a half of work before 08:00.
This ability to run on minimal rest without daytime fatigue runs in her family, including her father and brother. For the general population, however, the target is much higher. The average adult aged 26 to 64 requires roughly seven to nine hours of sleep every 24 hours, according to the US National Sleep Foundation’s latest review.
Familial Natural Short Sleep Genetics
The underlying mechanism for this phenomenon began to come into focus in 2019, when Bernard learned she carried a rare, heritable condition known as familial natural short sleep. That year, a research team from the University of California, San Francisco, identified a genetic mutation linked to human sleep duration. Carriers of this mutation typically wake up very early, obtaining between four and six and a half hours of sleep nightly while maintaining normal daily function.
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Molecular biologist Ying-Hui Fu, who leads the investigative team at the university, notes that one of the enduring mysteries of familial natural short sleep is why carriers appear entirely fine on so little rest. In the years since the initial discovery, researchers have identified several additional mutations associated with the trait.
Our Future Health Study Findings Across the UK
While genetic short sleepers represent a rare exception, broader population data reveals widespread sleep deficits. Recent findings from 1.9 million participants in the Our Future Health research programme show that 25 per cent of adults in the UK fail to reach the recommended seven to nine hours of nightly rest.
Dr Iain Turnbull, deputy chief medical officer for Our Future Health, pointed to distinct behavioral indicators within the dataset. What really stands out from the incredible breadth and scale of this data is the number of people snoring and the high rates of daytime napping,
he noted, adding that both trends suggest large segments of the public lack sufficient sleep quality.
The study also highlights demographic divides in sleep patterns across the
- Nearly 32 per cent of participants report being kept awake by a partner’s snoring.
- Men show higher rates of both napping and snoring, yet they are slightly more likely than women to hit the recommended sleep duration.
- In the southwest region, men are more likely to secure the suggested seven to nine hours than women.
- Younger adults in their late teens and 20s report the highest sleep totals, whereas individuals in their early 50s report the lowest.
Animal Models and Twin Research Insights
To understand whether these genetic variations actively shield the body from harm, researchers have turned to laboratory models and human studies. A 2019 experiment led by Ying-Hui Fu introduced a familial natural short sleep mutation into mice. The modified mice not only slept less but appeared safeguarded against memory deficits, with additional tests showing a reduced likelihood of developing a mouse variant of Alzheimer’s disease.
Human research provides parallel clues. An international team examined a pair of fraternal twins in 2014, where only one twin carried a short-sleep mutation. The carrier twin slept about an hour less than his sibling each night. When both brothers were kept awake continuously for 38 hours, the carrier twin experienced roughly 40 percent fewer performance lapses.
Furthermore, sleep monitoring revealed that despite sleeping less overall, the carrier twin obtained nearly identical amounts of non-REM sleep—including deep slow-wave sleep—as his brother. This suggests short sleepers may extract a higher density of restorative benefits from the hours they do spend in bed.
Pharmaceutical Ambitions and Long-Term Risks
The intersection of genetics and sleep science has generated considerable interest within the pharmaceutical industry. Researchers harbor long-term hopes that decoding these natural variations could eventually yield new treatments for sleep disorders or enable military personnel to function safely on reduced rest.
However, scientists emphasize that much more work remains before any such applications can be safely developed. Without a precise understanding of the biological pathways involved, manipulating sleep duration could carry severe, delayed consequences.
You have to understand how it works. You don’t want to sleep less and then get Alzheimer’s or Parkinson’s or cancer after 10 years, or five years, or 20 years.
Ying-Hui Fu, molecular biologist and lead investigator via BBC