In the first chapter of Why We Sleep, Walker:
Given the density of scientific and factual errors and an apparent invention of new “facts” by Walker, I would caution readers against taking the book’s recommendations at face value.
- completely misrepresents the relationship between sleep and longevity and between sleep and cancer (Section 1)
- erroneously states that getting a good night’s sleep is always beneficial (Section 2)
- erroneously states that patients with fatal familial insomnia die because of lack of sleep (Section 3)
- seems to invent a “fact” that the WHO has declared a “sleep loss epidemic” (Section 4)
- misrepresents National Sleep Foundation’s sleep recommendations and uses them to misrepresent the number of adults failing to get the recommended hours of sleep (Section 5)
- calls his book “a scientifically accurate intervention”
If you take one thing away from this entire essay, remember this: as long as you feel good, sleeping anywhere between 5 and 8 hours a night seems basically fine for your health (see Section 1), regardless of whatever Big Sleep wants you to believe.
All of the evidence we have about sleep and long-term health is in the form of those essentially meaningless correlational studies, but if you’re going to use bad science to guide your sleep habits, at least use accurate bad science.