Sleep: Summary of What I’ve Learned

I want to summarize what I’ve learned about how to sleep well. I’ve found about a dozen changes that helped. Taken together they suggest the importance of four dimensions:

1. Healthy brain. My sleep greatly improved when I ate a lot of pork fat. (As far as I can tell, butter produced the same effect.) I wasn’t getting enough animal fat. My sleep also improved when I started eating honey at bedtime. I assume honey raised blood sugar to better levels during sleep, improving brain performance. The great importance of this, I believe, is why we evolved preferences that push us to eat strongly sweet foods, such as fruit, separately and later, i.e., dessert. Bedtime honey also caused my muscles to grow more in response to exercise — a sign of better sleep, since muscles grow during sleep. I have never measured the effect of flaxseed/flaxseed oil on my sleep but the brain benefit was so clear in other ways I’d be surprised if it didn’t improve sleep.

2. Strong oscillation. Sleep is controlled by three oscillators. The larger the amplitude of their summed output, the deeper sleep.

One oscillator — the well-known one — is sensitive to the light/dark cycle (especially blue light). It makes us active and awake during the day, inactive and asleep at night. Its amplitude depends on the amplitude of the light/dark cycle, which can be increased by sunlight or daylight fluorescent light in the morning, a darker bedroom, and less blue light in the evening. Vitamin D3 in the morning seems to have the same effect as sunlight, and is much more convenient.

A second oscillator is sensitive to when we eat. To ensure we’re active when food is available, it wakes us up about three hours earlier. If you usually eat at noon, for example, it will wake you up at 9 am. I realized the practical importance of this oscillator, which is well known to circadian-rhythm researchers, when I found that not eating breakfast reduced how often I woke up too early.

The third oscillator is controlled by the sight of faces — what you see during a conversation. It also controls mood, making us happy, eager, and serene during the day and unhappy, reluctant, and irritable at night . If things are working properly, most of the bad mood will happen while we are asleep. During a critical period in the morning, faces “push” this oscillator much as you push a swing. It evolved to synchronize the sleep and mood of a community so that everyone is awake, happy and eager to work at the same time. Two people cannot work together if one of them is asleep.

3. “Poison” avoidance. Alcohol and caffeine can make my sleep worse, no surprise there.

4. Muscle growth. Exercise that causes muscle growth deepens sleep, whereas aerobic exercise does not. (Aerobic exercise may make you fall asleep faster, which has never been a problem of mine.) Standing more than 8 hours during the day produced better sleep; less standing (such as 6 hours) did not. This was too hard to be practical. Later I found that standing on one leg to exhaustion had similar effects. That was practical — I still do it.

The biggest advances, compared to what was already known, are morning faces and bedtime honey (brought to my attention by Stuart King), with Vitamin D (discovered by Tara Grant) honorable mention.

A recent editorial in the New York Times described mainstream thinking:

The brief course of sleep therapy teaches patients to establish a regular wake-up time; get out of bed during waking periods; avoid reading, watching TV or other activities in bed; and eliminate daytime napping, among other tactics. It is distinct from standard sleep advice, like avoiding coffee and strenuous exercise too close to bedtime.

I imagine the health experts of 1950 gave similar advice.

Chris Masterjohn’s comments about sleep (thanks to Stuart King for the link) illustrate what a very smart very well-informed person figured out. Like me, he stresses animal fat and the light/dark cycle (morning sunlight and dark bedroom). Unlike me, he thinks a cool room helps. I have varied room temperature and didn’t notice a difference. He mentions Vitamin B6 but I eat enough meat that I am unlikely to be deficient. He says carbs help but doesn’t narrow it down to honey at bedtime. He doesn’t mention morning faces or morning Vitamin D. Neither Chris nor I emphasize magnesium, which some people praise highly.

20 Responses to “Sleep: Summary of What I’ve Learned”

  1. Brian Toomey Says:

    Great article Seth. Magnesium hasn’t helped me noticeably, but a cold room does. I sleep much worse in a hot room.

    A week of trying bedtime honey seemed to make me sleep slightly deeper, but push my sleep onset forward. Since I have sleep onset insomnia, I don’t think I’ll keep with it.

  2. Alex Chernavsky Says:

    Temperature has a significant effect on my sleep. I sleep worse in the summers.

  3. adamlong Says:

    Seth, I just want to say again how much I appreciate your blog and what you give back to the community. Since reading your blog I have made significant improvements to my sleep and it has really benefited the rest of my life substantially. I can’t remember if you’ve discussed this before but I wonder if you have tried the philips blue light or anything similar. My routine now is that I use orange goggles starting around 8 pm, and then (after taking honey) read in bed with a red light. I find I can’t read as long as I used to — I get drowsy very quickly. Then in the morning I use a philips sunrise alarm clock (just started using it recently) to wake up and then a philips golite to expose myself to blue light while drinking my coffee and while shaving. Then I go to the park across the street and do some exercise (indian clubs or sprinting) while facing the sun (one of the benefits of living in Southern California). I have not been rigorous the way you have about teasing out the effects of these different measures, but I can say that overall my sleep is MUCH better than it used to be and I feel that this has improved my mood and my life considerably.

    Seth: Thanks, that’s nice to hear. To answer your question, I put on orange goggles at 8 pm. Haven’t tried the blue light.

  4. Li Says:

    I’m surprised you don’t include actual activity – physical or mental – among the oscillators. There’s good reason to believe that the former, at least, impacts circadian rhythms.

  5. Jeff Davidson Says:

    Regarding oscillator number two – Bingo! Some time ago I began experimenting with eating high protein breakfasts within 30 minutes of arising as a way to reduce snacking later in the day. It worked admirably, but since I normally wake at 4AM for work, it didn’t take long for me to start having problems with waking at 1:30 – 2AM – quite alert – and not be able to fall back to sleep until, of course, 3:55AM.

    I was never aware of this affect, but I found the early waking subsided once I started skipping breakfast again.

    Seth: Definitely supports what I found.

  6. Jeff Davidson Says:

    @ adamlong, your bedtime routine sounds exactly like mine. It takes me a long time to read books nowadays.

  7. BRW Says:

    Great summary! I had never heard the 3 hour timing prior to breakfast wake up thing but, it fits with my occasional early rising.

    Thanks for sharing.

  8. Sentinel Says:

    @ adamlong – I tried the philips golite too, almost daily for 5 months. i have not noticed any change, but i am thinking that it might pay off over the winter, when the potential for access to sunlight is greatly reduced. the amber glasses seem to have assisted with reducing sleep latency (quickly falling asleep), however.

  9. Jeff Says:

    Seth -

    You mentioned in an earlier post that you take your Vitamin D 3 – 4 hours after wakening. Is the reason for this so you can take it with food and still avoid the early awakening effect of eating too close to rising?

  10. Jeff Says:

    adamlong & Jeff Davidson -

    Do you recommend any particular red reading light?

  11. Kjartan Says:

    About the morning faces, for what duration of watching faces have you found to be most effective? In your PDF you mention that you experimented with different amounts of time, but I didn’t see any mention or graph showing these results.

  12. Seth Roberts Says:

    I take my Vitamin D3 at 8:00 am. I don’t know if that is best but it seems to work. This has nothing to do with eating it with food — I don’t eat it with food.

    I think Vitamin D3 has the same effect as sunlight — I also try to get plenty of sunlight in the morning. I want those two things — Vitamin D3 and sunlight — to be working together, in synchrony. That will give me the greatest circadian rhythm amplitude and thus the deepest sleep. It’s as if two people are pushing a swing; you’d want their efforts to add rather than interfere. There’s no substitute for trial and error in finding out what time it is best to take Vitamin D.

  13. Seth Roberts Says:

    I don’t exercise in the evening. I do in the morning, a little bit, you are right I should wonder about it.

  14. Seth Roberts Says:

    What duration of faces most effective?

    The longer the better. I usually stop somewhere between 30 and 50 minutes of faces.

  15. AT Natenshon Says:

    Hi Seth,

    Any reasons on why no emphasis on Magnesium, I have tried it and found it effective for both muscle cramping and sleep.

    Seth: In small tests it made no difference. It is hard for magnesium to cross the blood brain barrier, which might have something to do with the negative results. Maybe I should try it again.

  16. Bob Levinson Says:

    I always thought that coffee in the morning was safe. Calling it “poison” (see number 3 above) led me to this study, which suggests otherwise. Too bad, it will be difficult to quit!

    Seth: I have two cups of black tea in the morning. No more the rest of the day. Black tea has half the caffeine of coffee. After reading that study I may reduce it to 1 cup of black tea per day.

  17. Baeo Maltinsky Says:

    Eggs seem to cause me horrible insomnia.

    Back around July 2012, I was trying to improve my diet but I didn’t want to give up my vegetarianism, so I started to eat a LOT of eggs. The quantity varied a bit over time but was usually in the range of 10 to 14 per day. Not long after, I started having awful insomnia. I could lie awake all night just unable to fall asleep. There were suddenly just too many thoughts buzzing through my head keeping me up. It was like something was engaging my sympathetic nervous system. I thought it probably had something to do with my dietary changes, but I assumed that it was a result of ketosis disturbing sleep. I tried reintroducing carbs, but when that didn’t work I just sort of gave up on dietary modifications (except for when I began supplementing Vitamin D in the morning, but that only helped marginally). I started cycling through OTC sleep aids, but that only sort of worked as I developed tolerance to anticholinergics very quickly and melatonin didn’t work at all.

    By October 2013, I was going crazy. I just couldn’t sleep well. It was making me depressed and seriously impairing my academic performance. I was exhausted constantly, but then I noticed something. I slept better when I consumed a lot of caffeine in the morning. I played around with it a bit, and noticed that there was a clear dose dependent relationship between how much caffeine I consumed and how well I slept. Now, there are good reasons not to consume that much caffeine, but it got me looking in the right direction. I had a hunch that the caffeine was depleting my acetylcholine levels, serving a similar function as OTC anticholinergics like diphenhydramine and kava.

    I wondered what would happen if I sharply reduced my intake of acetylcholine precursors. A lot of people advertise eggs as “choline packed”, so I cut back to less than 3 per day. Suddenly, I was sleeping much better. Now, it could be something else in the eggs (I’m not really attached to my choline hypothesis), but either way I feel confident blaming them for my sleep troubles.. My insomnia is just gone now, and it returns whenever I start eating them again.

    Seth: Great story.

  18. tom Says:

    I measure my sleep with a fitbit. It just measures motion. Hopefully it corresponds with REM and stage 3 sleep. “What you measure, improves” – Rumsfeld’s Rules. But if my sleep is really bad, it logs it under the activity window instead, and I have to edit it to make it a sleep log.

  19. Nathanael Says:

    For reference, I researched magnesium heavily. Basically, if you have a magnesium deficiency, sleep problems are only one of the many nasty effects — constantly tense muscles are the most common.

    If you have magnesium deficiency, you need to correct it by taking magnesium. You can’t be tested for magnesium deficiency by blood test because it doesn’t “hang out” in the blood — you can have a deficiency which can’t be found in blood tests very easily. And due to magnesium-depleted soil, it’s become much easier to be magnesium-deficient than it was 100 years ago.

    But if you don’t have magnesium deficiency, magnesium will of course do nothing.

    Seth: I live in Beijing half the year, Berkeley half the year. To my surprise, I seem to be healthier in Beijing, judging by brain test scores. I eat about the same food in both places. The reason may be that in Beijing I drink bottled water with magnesium added, in Berkeley the water I drink does not have magnesium added. I have tried magnesium supplements and they had no effect — but that was in Beijing. Haven’t tried them in Berkeley.

  20. daz Says:

    @Baeo,
    on the Choline ‘thing’, i was reading recently that choline (too much?) is not good for people prone to high histamine levels.
    also choline needs to be in balance with inositol, so may be you are (or your diet is) deficient in inositol. & apparently caffeine can produce an inositol deficiency.
    just some food for thought…