Natural short sleepers: why you can’t train yourself to need less sleep

Scientists describe rare people who have a lifelong tendency to sleep only about 4–6 hours a night and still feel well rested. They are called natural short sleepers. (Shi et al., Neuron 2019)

This article is an explanation; it is not a diagnosis or a guide to sleeping less.

What “natural short sleep” means

• These are not people who “trained” themselves, but a lifelong trait — short sleep while still feeling rested. (Shi et al., Neuron 2019)
• Scientists described the first family case in 2009: in a small family with two affected people, mutation carriers reported sleeping 6.25 hours on average, relatives without the mutation 8.06 hours. (He et al., Science 2009)
• By 2019, researchers had identified more than 50 families in which people need less than 6.5 hours of sleep throughout life. (Shi et al., Neuron 2019)

Which genes scientists found

• DEC2: mice carrying the human mutation in this gene stayed awake longer and slept less. (He et al., Science 2009)
• According to a later study, the altered DEC2 dampens the gene for orexin — a substance that helps the brain stay awake — less, so the mice have more of it. (Hirano et al., PNAS 2018)
• ADRB1: a rare mutation of the β1 receptor in another short-sleeping family; mice carrying it slept about 55 minutes less per day. Nerve cells with this receptor in a brainstem area (the dorsal pons) are active during wakefulness and REM sleep. (Shi et al., Neuron 2019)
• The authors note, however, that the amount of sleep we need is probably shaped by many variants in many genes — there is no single “short-sleep gene”. (Shi et al., Neuron 2019)

Why this doesn’t mean you can do it too

• NHLBI: experts recommend that adults sleep 7 to 9 hours; adults who sleep less than 7 hours may have more health issues. (NHLBI — How Much Sleep Is Enough?)
• NHLBI explicitly calls the idea that people can learn to get by on little sleep with no negative effects a common myth. (NHLBI — Sleep Deprivation and Deficiency)
• People who are sleep deficient may not realise it, according to NHLBI, and may think they function well. (NHLBI — Health Effects)
• Sleep deficiency is linked to heart disease, high blood pressure, diabetes, depression and injuries — for example from sleepiness while driving. (NHLBI — Sleep Deprivation and Deficiency)
• The authors of the DEC2–orexin study write that most people need roughly 8 to 8.5 hours to feel good and function at their best — short sleepers are the exception. (Hirano et al., PNAS 2018)

How to tell you are sleeping too little

• According to NHLBI, sleep deficiency shows up as feeling very tired during the day and not feeling refreshed and alert when you wake up. (NHLBI — Health Effects)
• Trouble with decisions, problem-solving and controlling emotions can follow. (NHLBI — Health Effects)
• If you recognise yourself here, it is far more likely that you are short of sleep than that you are one of the rare natural short sleepers.

When to see a doctor

• See a GP if sleep problems persist after changing your habits, last for months or spoil your day. (NHS — Insomnia)
• This AI health check is not a medical review. This article is not medical advice.

Takeaways

1. Natural short sleepers exist, but they are very rare.
2. It is a lifelong, largely genetic trait — not training.
3. Most adults need 7 to 9 hours.
4. People short of sleep often don’t notice it themselves.
5. Daytime tiredness is a signal, not proof of a “short-sleep gene”.

The genetics of short sleepers is fascinating — but for most of us, the best strategy is to give the body as much sleep as it truly needs.