A recent PatientsLikeMe survey found a strong correlation between chronic illness and poor sleep. Here are the most interesting results:
PatientsLikeMe survey respondents in the U.S. (n=3,284) . . . are almost nine times more likely to [have] insomnia than the general adult population. . . . PatientsLikeMe members with health conditions experience [each] of the four symptoms of insomnia [= trouble falling asleep, trouble staying asleep, early awakening, and waking up not rested] at twice the rate of the general adult population.
This supports my view that bad sleep causes illness. The correlations could have plausibly been the other way (better sleep among survey respondents). People sleep more when sick. Whatever makes sick people sleep more might also make them fall asleep faster and wake up less often.
If I slept poorly, I would move heaven and earth to sleep better. (But would never take sleeping pills.) I sleep well, actually, but I still track my sleep and do various experiments to see if I can improve it. For example, recently I was puzzled why I was sleeping less well in Berkeley than in Beijing. One possibility was that my Beijing bedroom was darker than my Berkeley bedroom, even though my Berkeley bedroom was quite dark (e.g., no light from a street lamp). I made my Berkeley bedroom even darker and found my sleep improved. It really was cause and effect. When I made my Berkeley bedroom lighter, my sleep got worse.
My enormous concern with sleep — nothing matters more for health — seems to put me in a tiny minority. Even sleep researchers don’t say bad sleep causes sickness. However, Robb Wolf agrees with me. He has said, “If someone sleeps poorly it is hard to keep them alive. If someone sleeps well, it is hard to kill them” — a good way of putting it. At the recent Ancestral Health Symposium in Atlanta, I asked him where he got this. He said it was based on his experience, meaning his experience working with other people.
My view is heavily based on my experience of my own health. Exactly when I greatly improved my sleep, I greatly improved my health. I stopped getting obvious colds. The people around me continued to get them. I hadn’t expected this. In the research literature I found plenty of support for the idea that better sleep causes better health. An example is that poorer health during the winter seems to be due to less light, not the cold. I am sure morning sunlight improves sleep. Vitamin D has been associated with dozens of measures of health (more Vitamin D, better health). This too may reflect the underlying causality better sleep –> better health because sunlight increases Vitamin D and improves sleep. That morning Vitamin D improves sleep (Tara Grant’s great discovery) be important here. Epidemiologists should always measure sleep the way they always measure smoking. Now they almost never do.
Thanks to Richard Sprague.
More “Even sleep researchers don’t say that bad sleep causes illness” — that’s wrong. Here’s an example:
Yet there’s strong evidence that lost sleep is a serious matter. The Sleep in America polls and several large studies have linked sleep deficits with poor work performance, driving accidents, relationship problems, and mood problems like anger and depression. A growing list of health risks has been documented in recent studies, too. Heart disease, diabetes, and obesity have all been linked with chronic sleep loss. “People just don’t realize how important sleep is, and what the health consequences are of not getting a good night’s sleep on a regular basis,” Hunt tells WebMD. “Sleep is just as important for overall health as diet and exercise.”
I should have said sleep researchers don’t connect good sleep with good immune function, which this quote illustrates.