I looked at my gums this morning. I had never seen them so pink (that is, non-red). They looked just like the picture of healthy gums at the dentist. As I explained yesterday, my gums are in good shape because I am drinking 4 tablespoons/day of flaxseed oil, which contains a lot of omega-3.

Meta-analyses of the effects of omega-3 have had trouble finding an effect. A meta-analysis about mood found a barely-reliable effect and concluded “the evidence available provides little support for the use of n–3 PUFAs to improve depressed mood.” (They should have said “ a little support.”) A meta-analysis about heart disease concluded “Long chain and shorter chain omega 3 fats do not have a clear effect on total mortality, combined cardiovascular events, or cancer.” The effect on total mortality was close to significant and there was evidence of heterogeneity (i.e., studies varied) so their results were not completely negative, as the authors noted in response to comments. The effect is just weak, apparently.

In other words, after combining many experiments, each experiment with dozens or hundreds of subjects, meta-analyses can barely see an effect of omega-3. Yet I found a perfectly clear effect with one subject? An effect I wasn’t even looking for? That seems discrepant, and worth trying to explain.

My explanation is this: What I had in my favor and all those other studies did not were the benefits of self-experimentation. In particular,

1. The effect on balance was so clear that I used it to find the best dose. I found that 3 tablespoons/day was better than 2 tablespoons/day and even at 3 T/day there was an effect of time of day. So I went to 4 T/day. It seemed no better than 3/T day, so I stopped there. Conventional studies have not been able to do anything like this.

2. The effect on balance was so clear that I could use it for quality control. If I happened to buy a bad bottle of flaxseed oil I would have noticed — the results would not have been consistent, starting from when I started the new bottle. (I have gone through about six bottles.) Previous studies have had little or no quality control. If half their omega-3 went bad, they would have had no way of knowing.

3. I was strongly motivated to take the flaxseed oil. I know it is beneficial. This is not the case in any double-blind experiment when treatment is compared to placebo. In such experiments, every subject has reason to doubt that taking the pill will make a difference.

4. Dosage in nutrition, as in these mood and heart disease studies, has been built around avoiding failure — for example, what dose will avoid heart disease? Whereas I was looking for the optimum. My brain does not fail in any obvious way if I don’t have enough omega-3; it just functions worse. The amounts needed to avoid obvious failure are probably (a) different for different parts of the body and (b) less than optimal. For example, the amount of omega-3 needed to avoid dementia may be 1 T/day whereas the amount needed to avoid heart disease may be 2 T/day. The optimal amount, the amount needed for best performance, is likely to be greater than all of these failure thresholds. It is a better target.

Something else in my favor, not related to self-experimentation is that I studied the effect of omega-3 on my balance — how long before I lost my balance, a measure that can have many values. In contrast, most omega-3 research has involved binary measures like mortality or heart attacks. Someone either dies or does not die, for example. Binary measures tell you less than many-valued measures.

Given these advantages, it makes sense that I could find a much clearer effect.

With a better understanding of how to measure balance, I looked again at my data about the effects of flaxseed oil. Here is a new, improved comparison of 2 tablespoons/day and 3 tablespoons/day:

Very clear difference: one-tailed p = .004.

Here is a messy comparison between 3 and 4 tablespoons/day:

I compared 3 tablespoons/day at 2 different times with 4 tablespoons/day divided between those 2 times. I didn’t want to take 4 tablespoons at one time and I wanted to have at least 2 tablespoons in the evening because of the sleep benefits. The graph shows that 4 tablespoons/day has about the same effect as 3.

The big picture: Earlier data convinced me there is probably an effect. Before doing more subtle, convincing, publishable experiments, I have been trying to make the effect as large as possible. For two reasons: 1. To make the effect as clear as possible. 2. To have the most beneficial possible baseline (a baseline to which I will return many times). I foresee doing an experimental design like this: baseline (n days), something else 1 (n days), baseline (n days), something else 2 (n days), baseline (n days), something else 3, and so on. During those many baseline days I want the effect to be as strong as possible.

Flaxseed oil seems to have detectable effects within hours. For example, I increased the dose in the evening and my balance was better the next morning. To get some sense of the time course of the effect, I varied the time of day that I took the flaxseed. I usually took it around 10 pm; I tried 10 am instead. I continued to test my balance around 7 am.

Here are the results from an ABA experiment.

Taking 3 tablespoons at 10 am produced better results than taking the same amount at 10 pm. I fit lines with equal slope to both the A (10 pm) and B (10 am) treatments, as the graph shows. The two lines had different intercepts, p < .05.

Although 10 am produces better balance, it produces worse sleep — more evidence that the sleep improvement and the balance improvement are due to different mechanisms. I want both improvements, so I am going to split my dose — half in the morning, half in the evening.

Of course, the fact that time of day of flaxseed oil matters is more reason to think that presence/absence of flaxseed oil matters. It is very hard to explain these results in terms of expectations: I had no reason to expect one time to be better than the other.