Science in Action: Omega-3 (sleep data)

When I started taking omega-3 the rationale was not crystal clear. Many Shangri-La dieters reported better sleep; the diet involves drinking fat; omega-3, a fat, may affect the brain; sleep is controlled by the brain. I had not noticed any change in my sleep when I switched from sugar water to ELOO. Maybe this was because ELOO was low in omega-3, I thought, and this is what prompted my interest in omega-3. Later, a fly in the ointment: a poll of SLDers found that ELOO was as likely to produce better sleep as other oils. Implying that it is not omega-3 that is producing better sleep. I was puzzled, but continued my omega-3 investigations, which by then were motivated by an unmistakable improvement in my balance. My sleep did seem to improve somewhat when I started taking flaxseed oil capsules (a good source of omega-3).

Now I think I understand. I recently changed the time of day that I take 3 tablespoons of flaxseed oil. I had been taking it around 10 pm every evening; I switched to 10 am every morning. I wondered if the change would affect my balance, which I test around 7 am every morning.

To my surprise the change affected my sleep: I started waking up earlier. That is, I slept fewer hours before I woke up. This was not good — in general, the longer I sleep in one continuous stretch at night, the better. I was waking earlier and less rested. My impression was that my sleep was reverting to an earlier, lower-quality state.

To confirm this, I entered a lot of my sleep data into my computer and made a graph of how the length of my sleep (my “1st” sleep, to distinguish it from sleep when I fall back asleep a few hours after waking up) varied over the last two years. Here is the graph:

T = tablespoon. The labels give the daily dose — e.g. “3 T flax” means 3 tablespoons/day of flaxseed oil. Each point is a mean. The error bars are standard errors. This graph shows that in recent months I had been sleeping longer. I had noticed this change: it was especially clear when I switched from 1 T/day flaxseed oil to 2 T/day. I thought the improvement was due to omega-3 — ignoring the fact that a switch to sesame oil (low in omega-3) didn’t eliminate it.

Now, with a third fact contradicting my original idea (the first two were the poll and the sesame oil results), I have finally managed to change my mind. It is fat in the evening that causes longer sleep. Not only omega-3 fat — perhaps any fat has this effect. Now all sorts of things make sense.

When I started drinking ELOO my sleep didn’t improve because I drank most of the ELOO during the day.

When I started the flaxseed oil capsules they had only a little effect on my sleep because I swallowed them throughout day as well as in the evening.

When I switched from 10 flaxseed oil capsules per day to 1 Tablespoon of flaxseed oil per day my sleep got longer because I always drank the tablespoon in one shot — around 10 pm. When I switched to 2 Tablespoons/day, I continued to drink it all at one time, around 10 pm. I attributed the improvement to the increase in omega-3; it was really due to the increased evening intake of fat.

ELOO and other fats helped many SLDers sleep better because they drank them in the evening.

If you want to try this, note that the effect was bigger with 2 tablespoons at 10 pm than with 1 tablespoon at 10 pm.

To be continued.