Author: Seth Roberts

Omega-3 and Arithmetic (continued)

Seth Roberts14 Comments

Tim Lundeen, a Bay Area software developer, previously posted here about what happened when he increased his daily dose of DHA (an omega-3 fat in fish oil) from 400 mg/day to 800 mg/day: The next day, the speed with which he did simple arithmetic (e.g., 7 + 3) increased. At that point he had only four days from the high-DHA condition. Now he has two months. Here it is:

Tim Lundeen's arithmetic data

The y axis is the total time taken to do a set of 100 simple arithmetic problems.

Bottom line: The improvement continued, at roughly the same level. Very good evidence for an effect.

Tim had earlier found that doses of 200 and 400 mg/day of DHA had no apparent effect.

My main posts about omega-3.

Interview about Self-Experimentation (postscript)

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One of my favorite writers is Vladimir Nabokov. When he was alive, I not only read all his books but tried to read every word he wrote (in English). I have a folder full of photocopied interviews from newspapers and magazines. Late in his career, after my folder had become thick, Nabokov did something surprising: Came out with a book of interviews (Strong Opinions — here and here are excerpts), which put into book form most of what was in my folder. He wrote his answers to interview questions so this made some sense. Yes!, I thought, these interviews are just as interesting as I’ve always thought. I’d already read each of them about five times; I read them a few more times in book form.

I was such a big fan of Nabokov, and I liked his written interviews so much, that posting my answers to interview questions (here and here) was not an emotionally-neutral event. Partly it was a huge thrill — like being on your favorite TV show. Like being Nabokov For a Day. And partly it was humbling: My answers were way way worse than his.

Does the Type of Fat in Your Diet Affect Your Brain?

Seth Roberts8 Comments

Here’s how a Ph.D. student at UC San Francisco doing research on neural stem cells answered that question:

If dietary fat affected the brain in a significant way, we would know about it. It would have been discovered. Which isn’t to say it doesn’t affect it in a trivial way. Not just an acute action — like if you drink a small amount of alcohol or the effect of a sugar high. I mean the long-term functioning.

Why?

Because a lot of people would have tested it. Fat gets a lot of money. It’s a crowded area of research. People try to exploit it. It’s an area with a lot of public interest. It’s very popular to study anything related to fat. Also anything related to the brain. People are worried that they will lose their mind as they age. If there was something significant found it would have been a big story all over the New York Times.

She was very sure of this, it seemed to me.

My main posts about omega-3.

Interview about Self-Experimentation (part 2 of 2)

Seth Roberts2 Comments

8. How do you verify your results?

Repetition — first by me, later by others.

9. It seems your whole life is nothing but a self-experiment – how can your friends handle this?

Well, I spend a few hours in the morning differently than anyone else. I go to sleep earlier and wake up earlier than most people around me. And I eat less than most people. I like to think I make up for it by being in a better mood.

10. How do your colleagues react to your self-experiments?

Most of them think self-experimentation is a mistake, a waste of time. A few think it is creative and important.

11. Your most recent research is dealing with the effects of omega-3 on dental health. What is this research exactly about?

It’s not about dental health – that effect (omega-3 improved my gums) was an accident. It’s about the effects of omega-3 on my brain. I am varying the omega-3 in my diet in various ways and measuring how well my brain works in various ways. I began this research when I discovered that swallowing flaxseed oil capsules improved my balance. I was surprised but the effect makes sense: balance is controlled by the brain and the brain is more than half fat. Maybe you need the right fats in your diet if you want your brain to work as well as possible.

12. How did you get the idea of searching for the relation between omega-3 and dental health?

See answer to previous question.

13. How did you get the idea of taking oil to lose weight?

It was a three-step process. Step 1: I came up with a new theory of weight control. Step 2: I accidentally lost my appetite during a trip to Paris. I guessed that the cause was the unfamiliar sugar-sweetened soft drinks I’d been drinking because of the heat. This led me to discover that drinking small amounts of sugar water cause a lot of weight loss. Step 3: A friend pointed out that my theory predicted that flavorless oil should be just as effective as sugar water.

14. Are you going to search for a medical explanation for the effects of omega-3 fats?

No. Just convincing most people that there are effects is hard enough. It will also take a long time to learn how to maximize the effects. For example, what oils are best? How much oil is best? Other people are in a better position than me to try to explain the effects. But I don’t think it is terribly mysterious or surprising that dietary omega-3 should improve brain function: the brain is more than half fat. Surely the type of fat matters. My discovery is how big and fast the effect is. That’s not obvious.

15. When you consider your work as a whole, what is the most important result of your scientific research via self-experimentation?

Discovery of the effect of morning faces on mood. I believe depression is a deficiency disease, caused by too little exposure to morning faces. (See this paper for details.) No doubt that sounds very odd — even odder than the Shangri-La Diet — but consider this. In a wonderful book called The Good Women of China, the author, a Chinese radio host named Xinran Xue, wrote about her travels all over China to learn how different women lived. The last chapter is about visiting an extremely poor and backward community called Shouting Hill where an egg is a luxury and each women has multiple husbands because two or three girls are traded for a wife. She comes back to the radio station and tells her colleagues what she has seen. One of them asks, “Are they happy?” Another says, “Don’t be ridiculous, how could they be happy?” Because they were so poor — very poor even by Chinese standards. Xue answered:

I said to Mengxing that, out of the hundreds of Chinese women I had spoken to over nearly ten years of broadcasting and journalism, the women of Shouting Hill were the only ones to tell me they were happy.

It is pretty clear they saw plenty of faces in the morning.

Selenium, the Anti-Mercury

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I’ve been worried about the mercury in tuna. I didn’t know that selenium protects against mercury damage. See this paper, for example — see Table 1. Moreover, the same fish that contain mercury contain protective amounts of selenium. “It appears that selenium levels in fish are high enough to give protection against mercury toxicity,” concluded a review article. These important facts were missing from all discussions of the dangers of mercury in fish that I had seen, such as this one.

I already take selenium supplements because selenium protects against cancer. An especially convincing bit of evidence for this effect is a map of United States county-by-county colorectal cancer rates. There is a sharp separation of high- and low-rate areas along the Ohio and Mississippi Rivers. Attempts to explain the difference eventually decided it was due to selenium in the soil of the low-rate areas.

Durian and SLD

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The obvious connection between durian, the big smelly spiky Asian fruit, and the Shangri-La Diet is that both rely on flavor-calorie learning. We come to like the initially unpleasant smell and flavor of durian because we learn to associate it with the calories in the fruit. Here’s what happens:

“To anyone who doesn’t like durian it smells like a bunch of dead cats,” said Bob Halliday, a food writer in based Bangkok. “But as you get to appreciate durian, the smell is not offensive at all. It’s attractive.

From an article in today’s NY Times. The theory that led me to the SLD centers on flavor-calorie learning.

A less obvious connection is a principle that helped me discover that drinking sugar water causes weight loss. I was in Paris and lost my appetite — a rare event. The principle is that rare events are usually due to rare events. So I wondered what else unusual had happened. Well, there was something: I had been drinking several sugar-sweetened unfamiliar soft drinks per day. When I got back to Berkeley I started to test the possibility that sugar-sweetened water can cause weight loss and SLD was born.

For a fruit, durian has three rare properties:

    1. very strong, unpleasant smell
    2. very big
    3. hard to handle (because spiky)

Following the Rare-Causes-Rare principle, these should have a common explanation. Lightning does not strike thrice in one place for different reasons. According to Wikipedia,

The thorny armored covering of the fruit may have evolved because it discourages smaller animals, since larger animals are more likely to transport the seeds far from the parent tree.

That’s a good explanation of #3 and it explains the other two rare features (#1 and #2) as well. The reason for the strong smell (#1) is so that the signal will be broadcast a long distance: Large animals are less dense than small animals. We think of the smell of ripe durian as very unpleasant but perhaps almost all unfamiliar smells are unpleasant; so any random strong smell will seem very unpleasant. Big fruit (#2) means big tree and big tree means that seeds must be carried far away so as to be placed in soil where they will not compete with the mother tree. Coconuts are big and hard to eat. Pineapples are big and spiky.

The Rare-Causes-Rare principle also helped me discover the effect of morning faces on my mood and the effect of omega-3 on my balance.

Interview about Self-Experimentation (part 1 of 2)

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For a German magazine, I’ve been answering some questions about self-experimentation. Here are the first seven questions and my answers:

1. When and why did you came up with the idea of performing a self-experiment for the first time Mr. Roberts?

I started self-experimentation as a graduate student. My field of study was experimental psychology so it was important to learn how to do experiments. “The best way to learn is to do,” I had read. So the more experiments I did the more I would learn. Self-experiments were easy and fast. So I started doing them to increase how quickly I learned about experimentation.

2.Now, self-experimentation must be considered as an inherent part of your scientific work – or is it rather a bauble?

Self-experimentation has been the most influential work of mine by far. Lots of surprises and practical applications.

3. Your self-experiments always deal with very personal concerns like sleep disorders, depressions, procrastination or weight control. Has self-experimentation changed your life?

Yes. Sleep, weight, mood, general health, brain – all better. And it is very satisfying to help people. Thousands of people have used my ideas (described in The Shangri-La Diet) to lose weight.

4. What is the role of coincidence in your self-experimentation?

Most of my self-experimentation has started with an unexpected change. I changed my breakfast; my sleep got worse. I started taking flaxseed oil capsules; my balance improved. I started to stand a lot and my sleep got better. I started walking outside in the morning; my sleep improved. I watched TV in the morning; my mood improved the next day. I drank unfamiliar soft drinks; I lost my appetite. Each of these surprises led to lots of self-experimentation.

5. By coincidence for example you found a relation between watching TV in the morning and your mood the following day. What made you looking at this?

I was hoping to improve my sleep. When we sleep is affected by when we have contact with other people. If you have contact with other people late at night, you will be awake later the following night. I knew about research that suggested that watching TV has the same effect on sleep as human contact. I wondered if my sleep was bad because I didn’t have contact with other people in the morning. Maybe TV could substitute for that, I thought. So I watched TV early one morning.

6. When experimenting on yourself, aren’t you taking a big risk for your health? Have there been self-experiments you would now describe as risky?

Doctors have done risky self-experiments. I haven’t. I have studied the effects of very common things – watching TV, not eating breakfast, standing a lot. Millions of people have done these things without harm. They’re not dangerous.

7. Which of your experiments did you enjoy most?

Seeing faces in the morning. The effects are wonderful: I feel happy, serene, and energetic the next day. I’ve done several experiments about sleep. It feels great to wake up feeling very rested.

Omega-3 and Cognitive Decline

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It’s the golden age of omega-3 research. The February 2007 issue of the A merican Journal of Clinical Nutrition, perhaps the most prestigious nutrition journal, had two articles on the topic, the March issue seven (including four letters to the editor). The April issue has three (two research articles and an editorial), all on omega-3 and cognitive decline with age.

One was from Holland. Data were collected in 1990 and 1995 on 200-odd men, who were 70-89 in 1990. Those who ate fish had less cognitive decline from 1990 to 1995 than those who didn’t eat fish. A virtue of this paper is that the main results are shown graphically — a most basic point that AJCN papers usually get wrong.

The other study was done in Minneapolis. It looked at cognitive decline in about 2000 elderly men and women over a similar time period as the first study. Rather than asking subjects what they ate, this study measured blood levels of various fats. They did not find a reliable correlation between omega-3 levels and cognitive decline when considering all subjects but did find reliable (negative) correlations in subgroup analyses.

Both studies have selection problems. The first study looked at a small fraction of all the men in the study (total n = about 900) selected because of better health. I would have liked to see the results from the rest of the men. The second study did not correct for the vast number of significance tests done.

Both studies support — the second one quite weakly — the idea that omega-3s prevent cognitive decline. The main thing I notice is how difficult the research is. Data published 12 years after collection? Two thousand people studied twice, five years apart, with results barely different from noise?

The !Golden Rule and Reed College

Seth Roberts1 Comment

In the programming language R, ! is the negation function — !FALSE is TRUE, for example. The !Golden Rule, the opposite of the Golden Rule, is to treat others as you yourself do not wish to be treated.

An example comes from Colin Diver, the President of Reed College (my alma mater), who complains in an Atlantic Monthly piece about college rankings. Reed has opted out of the U.S. News and World Report rankings. President Diver explains why:

Trying to rank institutions of higher education is a little like trying to rank religions or philosophies.

That’s right: If different colleges have different goals, it is unfair and misleading to rank them on the same scale.

By far the most important consequence of sitting out the rankings game . . . is the freedom to pursue our own educational philosophy, not that of some newsmagazine.

Actually, you can pursue a singular educational philosophy in any case, rankings or no rankings. It’s just that the rankings punish you for doing so.

This is an example of the !Golden Rule because what President Diver complains about happens in every Reed classroom. All the students in a class are graded on the same scale with the same requirements. Perhaps different students have different goals, just as different colleges have different goals? Perhaps this system of grading punishes students with unusual goals, just as the U.S. News ranking system punishes colleges with unusual goals?

Made to Stick

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I went to a panel discussion last night. A professor — with vast public-speaking experience — gave a long boring introduction. “If only he had read Made to Stick!” I thought. The panelists were better but I wished they too had read Made to Stick.

MTS, by Chip Heath, a Stanford business professor, and Dan Heath, a corporate education consultant, tries to say what makes messages more or less memorable. They boil it down to six qualities. To be remembered, your message should be: 1. Simple. 2. Unexpected. 3. Concrete. 4. Credible. 5. Emotional. 6. Told with stories.

They complain that speakers and writers often “bury the lede” — fail to start with the most important compelling stuff. Well, their best story is buried in the middle of the book. Early in his class, Chip Heath has several students give brief talks. The class grades them. Ten minutes later everyone is asked what they remember from the talks. Hardly anything is remembered. The graded quality of the talk doesn’t matter: The “better” talks are remembered just as poorly as the “worse” talks. What is remembered are stories. But hardly anyone tells a story.

In other words, Stanford business students — and by extension the rest of us — don’t know how to give a good talk and don’t recognize a good talk when we hear one. We don’t know — and don’t know we don’t know. I agree. Our collective ignorance is enshrined in bad advice: Start your talk with a joke, for instance. MTS never says anything like that. It says: Start with a story.

Addendum: Seth Godin demonstrates.