Omega-3 and Mood Disorders

I subscribe to the Arbor Clinical Nutrition Updates. It is a nice way to slowly learn more about recent nutrition research. A partial subscription is free. Last week’s topic was omega-3 and mood disorders. The update summarized three articles:

1. Appleton KM. et al. Effects of n–3 long-chain polyunsaturated fatty acids on depressed mood: systematic review of published trials. Am J Clin Nutr 2006;84:1308 –16. This meta-analysis of 12 clinical trials found that omega-3 fats significantly reduced depression.

2. Frangou S. et al. Efficacy of ethyl-eicosapentaenoic acid in bipolar depression: randomised double-blind placebo-controlled study. Br J Psychiatry. 2006 Jan;188:46-50. This experiment found that an omega-3 fat helped persons with bipolar disorder.

3. Hallahan B. et al. Omega-3 fatty acid supplementation in patients with recurrent self-harm: Single-centre double-blind randomised controlled trial. Br J Psychiatry. 2007 Feb;190:118-122. This experiment found that omega-3 fats reduced a depression score.

I recently reviewed an article for the American Journal of Clinical Nutrition that found that omega-3 fats did not reduce depression scores. Unfortunately the article was not accepted for publication. I hope it gets published somewhere else.

Science in Action: Omega-3 (old data re-analysed)

A few months ago I did a little experiment to test my belief that omega-3 was affecting my balance. I replaced fats high in omega-3 (flaxseed oil and walnut oil) with a fat low in omega-3 (sesame oil). Here is a new analysis of the data:

walnut oil and flaxseed oil versus sesame oil

The raw data are the same. The new analysis differs from the earlier analysis in two ways: 1. How the number for each day is computed. The old analysis dropped the first 5 trials and took the mean of the rest. The new analysis fits a regression line to balance as a function of trial to estimate an effect of trial and subtract it, then takes a mean of all the trials. 2. Allowance for improvement. The new analysis, as the graph shows, fits a slope to all the data. The improvement over days is subtracted from each day’s score before the two conditions are compared.

The old analysis gave t = 4.1 (p = very tiny). The new one gives t = 6.3 (p = very very tiny). Big improvement!

Directory of my omega-3 posts.

Science in Action: Omega-3 (what’s the best dose?)

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:

2 vs 3 tablespoons/day

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

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

3 vs 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.

Science in Action: Omega-3 (measurement improvement)

I’ve learned a few things. As some of you may know, I’ve been measuring my balance by standing on a board that is balanced on a tiny platform (a pipe plug) — pictures here. Now and then the board would slip off the platform. I supposed this was a failure of balance but I wasn’t sure, especially if it happened as soon as I stood on it. So I got another board into which my brother-in-law kindly drilled the perfect-size hole so that the plug will never slip:

New board (with hole for plug)

To see if this made a difference I did an experiment with a design I have never used before but that I really like: ABABABAB… (one day per condition). In other words, Monday I tested my balance with the old board, Tuesday with the new board, Wednesday with the old board, Thursday with the new board, etc. Simple, efficient, well-balanced. Here are the results:

new board vs. old board

The red line is fit to the red points, the blue line to the blue points. The two lines are constrained to have the same slope.

Well, that’s clear. I expected my balance to be better with the new board, actually.

Speaking of the unexpected, I made another measurement improvement that truly surprises me — the surprise is that I never did it before. When I looked at my early balance data (the first 10 or so days of data) I saw that my balance improved for the first 5 trials and was roughly constant after that. Each session was 20 trials so I dropped (excluded) the first 5 trials from my analyses — considering them “warm-up” trials. I took the mean of the last 15 trials. That seemed very reasonable and I thought nothing of it.

Recently I asked again how performance changes over a session. The answer was a bit different: I found that performance improved for the first 10 trials. Now there are 30 trials in a session, so dropping the first 10 of them seemed okay. And that’s what I did.

But then I looked at how variability changed over a session. I expected the earliest trials to be more variable than the rest but the data didn’t show that. Variability was pretty constant from the first trials to the last. Hmm. Maybe I am losing valuable information by not including those early trials in my averages. It occurred to me: why not allow for the warmup effect by modelling it, rather than by excluding it? (Modelling it meaning estimating it and then subtracting it.) I did that, and then I looked at the size of the standard errors of the means (standard errors based on the residuals from the fit) for the most recent 40 days — essentially, the error in measurement. Here is what I found. Median standard errors:

First 10 trials (out of 30) excluded: 0.073
First 5 trials excluded: 0.064
First trial excluded: 0.061
No trials excluded: 0.059

My eyes opened wide when I saw these numbers. Oh my god! I was throwing away so much! A reduction in error from 0.073 to 0.059 — that’s 20% better.

Omega-3 and Bone Health

The current issue of the American Journal of Clinical Nutrition, which I mentioned yesterday, also has an interesting article about the effects of omega-3 on bone health. (Most recent issues of AJCN have something about omega-3.)

The researchers measured the bone density of about 80 teenagers and remeasured them about 5 years later. They found that bone density was positively correlated with the amount of omega-3 in the blood. A low correlation (0.3) but significant. Rat experiments support this connection. Again, it’s not just that omega-3 is good; omega-6 is bad — see the Israeli Paradox.

Science in Action: Omega-3 (time of day effect)

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.

Science in Action: Omega-3 (results with new measures)

Yesterday I blogged about three new measures of mental function that I have recently started to use. Here are the first results.

1. Memory-scanning.

early memory-scanning results

Each point is a mean; the error bars show standard errors. I expected a within-session warm-up effect (Trial 1 slower than Trials 2-5) but there isn’t one so I use variation across the 5 trials (100 digits each) to get a standard error.

2. Digit span.
early digit-span results

The program increases the number of digits to remember by one when I’m right and decreases that number by one when I’m wrong. The test continues until there have been six reversals in direction of the number of digits (e.g., the sequence 5, 6, 7, 8, 7, 6, 7, 8, 9, 8 contains three reversals). Each pair of reversals is averaged to get an estimate of digit span; I use between-average variation to get a standard error.

Digit span slowly improves with practice, other researchers have found. The increase is slow, however — one digit for every two hours doing the task.

3. Speeded arithmetic.

early speeded-arithmetic results

The questions differ greatly in how long they take (7*9 much slower than 1+0) so I fit a model to remove obvious effects and use the variation of the residuals to get standard errors. I think these results are so erratic because I did the test in several different places and in some cases I corrected mistakes (which is very slow). Now I don’t correct mistakes.

Science in Action: Omega-3 (new measures)

My balance measurements, such as this, this, and this, have come close to convincing me that flaxseed oil improves my balance. If a nutrient improves one part of my brain, it will probably improve other parts, too. So I’ve added three more measures of brain function to my daily tests:

1. Memory scanning. A paper-and-pen task. After studying three digits (e.g., “3 7 9”) for a few seconds, I go through a block of digits marking each one “in” (equal to 3, 7, or 9) or “out” (not equal) as fast as possible. Each test consists of 5 blocks of 100 digits. Duration: 5 minutes. Pluses: Similar to a well-studied task (Sternberg’s memory-scanning task). Minuses: Requires a little bit of equipment (sheet of digits).

2. Digit span. I see a series of digits on my laptop screen then try to remember them. The number of digits goes up and down depending on my accuracy. Duration: 4-6 minutes. Pluses: A well-studied task. Quite different than balance, memory scanning, and speeded arithmetic (below). No special equipment. Minuses: Little computation involved, unlike balance.

3. Speeded arithmetic. I do 100 simple arithmetic problems (e.g., 4 + 8, 3 * 5) as fast as possible. Duration: 2 minutes. Pluses: Tim Lundeen found an effect of fish oil on this task. No special equipment. Measures long-term memory retrieval, unlike other tasks. Intense — the 2 minutes are full of mental activity. Minuses: No obvious ones.

One of these may emerge as a better way to study the issue than balance measurements. The biggest problem with balance measurements is strong practice effects. The more often I measured, the better I became. (The area of my brain devoted to the task seemed to increase. The tiny balance platform seemed to grow.) Perhaps practice effects will be less of a problem with at least one of these tasks. Perhaps one of them will show clearer effects of flaxseed oil.

In a comment on an earlier post, someone suggested using chess as a measure. A fun test would be a good addition. Chess has two big problems: 1. Openings are time-consuming and quite different from the rest of the game. 2. If you take longer to make a move you can make a better move. So the amount of time allowed per move must be fixed. Which is less fun.

Omega-3 Greatest Hits

My main posts about omega-3 are:

Background
why I became interested
historical background
the Israeli Paradox
fat and anesthesia
the clouded crystal ball
omega-3 and cancer
unclear effects on heart disease
prison experiment

Procedure
equipment to measure balance
new measures
how best to measure balance
a new test
better measures
hand placement
letter-counting test
circle test

Results
practice effects
balance experiment (high-omega-3 fats vs low-omega-3 fat)
arithmetic (guest post)
arithmetic (continued)
sleep
first results with new measures
time-of-day effect
what’s the best dose?
flaxseed oil vs. olive oil (balance)
flaxseed oil vs. olive oil (memory-scanning)
flaxseed oil vs. olive oil (digit span)
flaxseed oil vs. nothing (balance)
flaxseed oil vs. nothing (arithmetic)
a surprise
time course (1st try)
time course (2nd try, plus egg surprise)
time course (very short experiment)
time course (circle test)
flaxseed oil: 2 T/day vs. 1 T/day (arithmetic test)

Discussion
sleep effect?
placebo effect?
overall discussion
source of injury-causing falls?
what the results mean
gum surgery cancelled
dental health
sports injuries (part 1)
sports injuries (part 2)
sports injuries (part 3)
sports injuries (part 4)

Overall Summary
abstract of conference talk

Omega-3 and Freakonomics

Steve Levitt, co-author of Freakonomics, has done me the great favor of bringing my omega-3 self-experimentation to a wider audience in this post. He thinks my results might be due to my expectations. I posted this comment:

Thanks, Steve, for writing about this. Here’s why I think the balance improvements I’ve noticed are unlikely to be due to expectations:

1. I first noticed the effect putting on my shoes the morning after I started taking flaxseed oil. I had been putting on my shoes standing up for two years; until that morning, I had always had trouble. Every morning. (I had expected it to get much easier — practice effect — but it didn’t.) The sudden improvement was a complete surprise. I had never heard of such an effect. I had hoped that flaxseed oil would improve my sleep.

2. The sudden improvement I saw when I switched from 2 tablespoons/day to 3 tablespoons/day was also a surprise, although I realize this may be harder to believe.

3. When I switched from flaxseed oil and walnut oil to sesame oil, I expected my balance to get worse. It did, but not when I expected. (It took 2 days to see a change; I expected to see it on the first day.)

Which is not to say I’m sure. If the effects I’ve seen are repeatable, I’ll test myself not knowing what oil I’ve ingested.

And forgot to sign my name. Oops.

My reading of the data (such as this) is that placebo effects sometimes exist but are vastly overrated — like many dangers.

Addendum: Stephen Dubner, Levitt’s co-author, blogged today that

nearly everything we’ve written about, either in the book or our journalism or the blog, has some element of people worrying too much about something

Pregnancy and Omega-3

A new study has found that mothers who eat more fish (high in omega-3 fats) during pregnancy have smarter, better-behaved children. Many expected the opposite: They assumed more fish = more mercury = more damage. Here is a newspaper story about it.

The study, which appeared in The Lancet, has an odd title: “Maternal seafood consumption during pregnancy . . . ” — as if paternal seafood consumption during pregnancy could affect the fetus. It involved about 10,000 pregnant women. The seafood/better-brain correlation was seen with several measures, including IQ scores at age 8. The authors tested the explanation that low seafood consumption was simply a marker for an unhealthy diet by taking dietary quality into account in various ways; this had little effect on the results, the authors say.

Current Food and Drug Administration advice to limit seafood consumption during pregnancy may be harmful, the authors note.

Thanks to Timothy Beneke for the pointer.

Science in Action: Omega-3 (sleep data, discussed)

This is a discussion of the facts and ideas in my previous post. In summary, several observations, involving both me and others, suggest that a few tablespoons of oil (at least olive oil, sesame oil, and flaxseed oil) in the evening improve sleep.

I’m not yet sure of this conclusion, even for myself. But several things are already worth pointing out:

1. It took several facts to change my mind (I originally thought the sleep improvement was due to omega-3 fat and had nothing to do with when I ingested it) but it did happen. Strangely enough, it happened when I was studying something else: The effect of omega-3 on my balance. I switched the time I drank flaxseed oil from 10 pm to 10 am to see if this affected my balance. (I don’t yet know the answer.)

2. The conclusion that a few tablespoons of fat late in the evening improves sleep is remarkably isolated. I have never read anything similar in the scientific or self-help literature. Most of my self-experimental conclusions, however odd they may strike outsiders (such as my recommendation to skip breakfast), are supported by many mainstream scientific results. (The breakfast conclusion, for example, is supported by dozens of studies of anticipatory activity in animals.)

3. It’s a big effect — one more hour of sleep per night. No wonder most Shangri-La dieters noticed it.

4. The long-term records of my sleep, which I had kept for no particular reason, came in handy. They made it clear that something had recently caused me to sleep longer each night. Which implied that it couldn’t be fat per se that caused the improvement — I’d been drinking ELOO (extra-light olive oil) for the past two years. The term self-experimentation doesn’t obviously encompass keeping such long-term records; they are better suggested by the term self-observation or even numerical self-observation. But whatever the term, they don’t have an obvious correlate in more conventional science. Experiments with yourself as the subject are just conventional experiments writ small and personal, you could say. But there is no part of conventional science that tracks people closely year after year. It makes scientific sense; it would be a way of getting new ideas. You might track 100 people (say). When someone’s health markers got suddenly better or worse you would investigate. This could be done; it isn’t.

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:

Length of 1st sleep over time

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.

    Omega-3 and Arithmetic

    After I posted my recent omega-3 results, Tim Lundeen, a Bay Area software developer, commented that his scores on an arithmetic test had improved after he had increased his omega-3 intake because of my results. I invited him to guest-blog about this:

    For the last year [Tim wrote] I’ve been been working on feeling better, trying to recover some of the energy and mental acuity that (I like to think) I used to have. As part of my program, I got Dr. Ryuta Kawashima’s book, Train Your Brain. His MRI studies have shown that simple arithmetic problems, done with time pressure, improve overall brain function. His book has 60 problem sets, each with 100 simple arithmetic problems such as 7 x 9 or 13 – 5.

    Here are my results from 90 days of tests, including several breaks of 1 to 3 weeks (lower numbers are better):

    Tim Lundeen's arithmetic results

    I started out at about 110 seconds per problem set, improved to 80-82 seconds per set, and got stuck there. Each time I took a break due to travel or other distractions, I would start up at about 95 seconds and quickly come back down to my 80-82 second range.

    Until the last 4 days. As part of my program to feel better, I started taking a DHA supplement. (DHA is found in fish oil. It is an omega-3 fatty acid that is preferred by the brain). I started taking 200 mg/day of DHA about 4 months ago, and didn’t notice any effects, good or bad. So two months ago I increased the dose to 400 mg/day. Again I didn’t notice any effects. After reading about the effects of Seth’s omega-3 supplements, I increased my DHA by 400 mg/day to 800 mg/day. The supplements, plus omega-3 eggs, some flax oil (partially converted in the body to DHA), and some fish and oysters, put me well over the 1g/day recommended level. (When I have fish or oysters I take only 600 mg of DHA instead of 800mg.)

    I do the arithmetic test about 8 am every morning. I take the DHA supplement about 9 am. The effect of the 400 mg increase was immediate: The next morning my score dropped to 76-77 seconds, about 5% better than I’ve ever seen on a regular basis. I made the change 5 days ago. The last 4 days are 4 of my 5 all-time best scores. It is fascinating to have another data point connecting brain function with omega-3 supplements.

    The supplements I take are from iNutritionals. They are $0.58/200 mg capsule ($35/bottle). They are from algae and are tasteless/odorless. No aftertaste or unpleasant effects. I tried a fish oil supplement a couple of years ago and couldn’t take it because of the fishy taste and aftertaste.

    About me: I’m CEO of Web Crossing, Inc. My best-known product is Microsoft Works for the Macintosh, which sold millions of copies.

    The Hidden Relevance of Experimental Psychology

    I used to teach introductory psychology. As I skimmed introductory psych texts, I could sense the disinterest that almost all the authors of these books had for my field — experimental psychology. Pavlov, memory — that was boring. What did that stuff have to do with everyday life? the authors seemed to be saying.

    The Shangri-La Diet was built on thousands of experiments about Pavlovian learning. Empirical generalizations from that data helped me make the mental jump from experiments by Israel Ramirez to a new theory of weight control. A conceptual understanding of Pavlovian learning (what makes an association weak or strong) allowed me to use the new theory to find new ways of losing weight. Suddenly that boring stuff was relevant.

    My omega-3 findings (such as this), if they hold up, would do the same thing for two other areas of experimental psychology. The experimental designs I use, such as ABA, are straight from Skinnerian psychology. Although I am now measuring my balance — not part of experimental psychology — my guess is that most of the measurements will eventually be more “mental.” I assume that omega-3s improve my whole brain, not just the balance-related part. Experimental psychologists have spent 100 years developing simple and effective measures of many mental functions; all that measurement work should help us figure out how much omega-3 and omega-6 we should consume. Too little omega-3 and too much omega-6 appear to cause a vast range of health problems, including the most serious. The problem is that it is extremely hard to measure the functioning of our immune system or our circulatory system or most other parts of our body. It is even hard to measure how well our mood-regulating system is working. (Too little omega-3 appears to increase the risk of bipolar disorder.) It is much easier to measure memory.

    Experimental psychology can be divided into two parts — human (Part A) and animal (Part B). Part B can be subdivided into B1 (Skinnerian) and B2 (associative learning). Part B2 can be subdivided into B21 (Pavlovian learning) and B22 (instrumental learning). If you know the field you know these are the natural divisions. All my mainstream work has been in B22. I have managed (or hope to manage) to show the relevance of every area of experimental psychology except my own. Curious.

    Science in Action: Omega-3 (more data)

    This experiment isn’t finished but these results are too fascinating not to share:

    Effect of flaxseed oil on my balance

    Each point is a mean of 25 trials. The bars are standard errors.

    Every evening around 9-10 pm I drank 2 or 3 tablespoons of flaxseed oil (with my nose clipped shut). Every morning around 7-8 am I measured my balance — how long I could balance on one leg on a small platform. (My balance-ometer.) I drank 2 tablespoons of flaxseed oil for 7 days then switched to 3 tablespoons.

    The morning after the first 3-tablespoon dose was magical. From the very first trial I could tell my balance was better. It had always been hard to balance for much longer than 4 seconds. Now, all of a sudden, I could balance for 6 seconds, and even longer. More impressive to me than the conclusion that omega-3 (flaxseed oil is high in omega-3) had improved my brain function is (a) how easy it was to detect the difference between 2 and 3 tablespoons and (b) a fairly high dose (2 tablespoons/day of flaxseed oil contain about 14 g ALA, the shorter-chain omega-3) was less than optimal. Flaxseed oil labels recommend 1-2 Tablespoons/day.

    Earlier data.

    Omega-3 Facts of the Day

    1. In the 1960s, Greenland Eskimos ate a diet very high in omega-3s.

    2. In the 1960s, Greenland Eskimos had very low rates of psoriasis. The Danish rate of psoriasis was 20 times the Eskimo rate.

    3. High omega-3 intake reduces inflammatory intercellular signals.

    4. Psoriasis is beginning to be considered an autoimmune disease.

    It’s not the same type of fact but on the SLD forums spacehoppa reported her rheumatoid arthritis was in remission, apparently from omega-3s, for the first time in the 18 years since it was diagnosed. Her balance was also better.

    Science in Action: Omega-3 (methodological improvements)

    I realized (in both senses) several ways to improve my omega-3 self-experimentation:

    1. Simpler treatment. I had been drinking both walnut oil and flaxseed oil. For the sake of simplicity, I stopped the walnut oil. I continued to drink 2 tablespoons/day of flaxseed oil. I will vary the amount of flaxseed oil.

    2. More controlled measurement. Instead of balancing on any part of my right foot, I started balancing on only the balls of my right foot.

    3. More measurement. I measure my balance once/day. During that one session I had been measuring my balance 20 times (measuring how long I could stand on a platform before falling off — 20 durations). The first 5 durations were warm-up, leaving 15 durations that counted. I increased the total number of trials to 30. It was still easy; the whole thing takes about 10 minutes.

    4. A new measure. Anything that affects balance is likely to affect other mental abilities, I believe. To test this belief, I will start measuring my brain in a new way: a pencil-and-paper version of Saul Sternberg‘s memory-scanning task. It will take about 5 minutes.

    I started #1-3 about a week ago and will start #4 today.

    An Unexpected Benefit of Self-Experimentation

    A few days ago I ate a handful of peanuts. Uh-oh, I thought, will this make my brain work worse? Peanuts are high in omega-6. As regular readers of this blog know, when I increased my omega-3 intake several months ago, my balance got better. More recently, when I replaced high omega-3/low omega-6 oils with a low omega-3/high omega-6 oil, my balance got worse; when I returned to the high omega-3/low omega-6 oils, my balance went back up. (Details here.)

    To measure the effect of different fats on my brain I have been measuring my balance every morning. The morning after I ate the peanuts, my balance score was within normal limits. Meaning my brain was working no worse than usual. This was reassuring — an unexpected benefit of self-experimentation.

    In ten years, will there will be websites that people regularly visit to take a few mental tests? The tests would be a quick and easy measure of brain function. The sites would remember all your scores and would graphically compare your current score with your previous scores. One more way to procrastinate — but it would be good procrastination.

    Science in Action: Omega-3 (discussion of balance results)

    My recent omega-3 results encourage more self-experimentation to see if they can be repeated and extended. I’d be very surprised if they turn out to be due to expectations (“placebo effect”). First, the effect of going from high omega-3 to low omega-3 was different than what I expected. I did not expect the one-day lag. Second, the improvement from low omega-3 to high omega-3 repeated results that surprised me. When several months ago I increased my intake of omega-3 I was surprised to notice the next day it was easier to put on my shoes standing up.

    My general plan is to find what omega-3 intake produces the best balance and then compare many other fat intakes to that. If omega-3 really improves my balance, I would like to know:

    1. What is the effect of omega-6 fats? Do they reduce the effect of omega-3, as often claimed?

    2. What is the relative potency of different forms of omega-3? Fish oil omega-3 is supposedly more potent than flaxseed oil omega-3 but I worry about degradation during the trip from fish to store shelf.

    3. Does omega-9 have any effect?

    4. What other mental functions are affected?