Ying-Hui Fu, a UCSF professor of neurology and a pioneer in the study of sleep and genetics, explains the science behind weird sleep patterns and explains why closed eyes matter more than you think.
Q: What sparked your interest in the genetics of sleep?
A: In 1996, I was introduced to an elderly woman who had spent her life going from doctor to doctor to understand why her sleep schedule was so unusual. She always went to bed in the evening and got up in the middle of the night. To her, those odd hours—the so-called early bird behavior—felt like a curse. Her granddaughters had similar sleep schedules, and she feared the unconventional pattern would ruin her life.
Q: What did you find out about her?
A: We identified a genetic mutation that was responsible for her family’s odd sleep patterns. She was thrilled because for years she had been told it was all in her head. In reality, she had a mutation that forced her to follow this shifted sleep schedule in order to function normally. Since then, we’ve identified hundreds of other families who exhibit this extreme early riser behavior, as well as 50 families known as “natural short sleepers.”
Q: How did you discover these natural short sleepers?
A: While studying extreme early risers, we found a mutation in two members of a small family of extreme early risers. Interestingly, they didn’t go to bed early to compensate for their early awakening. Upon further investigation, we found that they belonged to an entirely new category – a group that we now call natural short sleepers.
Q: Can anyone become a natural short sleeper?
A: I don’t think there is a surefire way to do this, and I wouldn’t advise people to try it. Our brains are complicated machines with many intertwined neural pathways. These pathways determine mood, sleep, and cognitive functioning, and if you try to manipulate one pathway, you’re likely to affect another. However, one day we might have enough knowledge to intelligently optimize the system and help people sleep more efficiently.
Q: What is the most common misconception about sleep?
A: That it doesn’t matter. All evidence shows that it is like food, water and air – we cannot live without it. Sleep affects everything from our happiness to how quickly we process information, and those who sleep poorly are at increased risk for virtually every known disease. Bad sleep is a slow killer.
Q: How are sleep and illness related?
A: Alzheimer’s disease is a great example. When we are awake toxins build up in the brain and while we sleep our brain cleanses those toxins. Levels of amyloid beta, a protein associated with Alzheimer’s disease, are highest when we go to bed and lowest when we wake up because of this natural scrubbing process. So if you sleep less, amyloids can build up in your brain and put you at a higher risk of Alzheimer’s.
Q: How much does sleep affect cognitive function?
A: It’s hugely important. Without quality sleep, people cannot reach their full potential. If you sleep just two hours less every night for two weeks, you will reach about 70 percent of your capacity.
Q: What do you do to sleep better?
A: I go to bed at the same time every night, avoid scary movies and thrilling books before bed, and use earplugs. People have to find out what they are most sensitive to – like sound, light or temperature – and create the right environment.
The ideal way to determine your sleep needs
- Go on vacation then…
- Avoid caffeine and alcohol
- Track when you wake up naturally
- Track when you sleep naturally
- Apply the lessons learned at home