Month: January 2007

Science in Action: Omega-3 (balance results)

Seth Roberts6 Comments

Because many SLD dieters reported better sleep, I wondered if omega-3 improved sleep. I increased my omega-3 intake by switching from olive oil, which has little omega-3, to walnut oil and flaxseed oil, which have much more — especially flaxseed oil. The amount of oil stayed roughly the same. The night after the change, my sleep got better. To my surprise, so did my balance. The next morning, I found I could more easily put on my shoes while standing up. I had been putting on my shoes standing up for 2-3 years and it had never been this easy. (I put on my shoes standing up because I thought it might improve my balance.)

I devised a simple measure of balancing ability. I stood on one foot on a platform balanced on a small metal cylinder (a pipe plug). (I will post pictures.) The parts were easy to find. I tried cylinders of different sizes until the balancing was neither too easy nor too hard. The measure was how long I could stand on one foot on the platform, which measured with a stopwatch. I made these measurements in blocks of 20 (the first 5 were warmup, leaving 15).

My early attempts had two problems: (1) The dose was too low. I had been taking the flaxseed oil as capsules (10 1000-mg capsules/day). I started taking 1 T/day in liquid form (much faster). Then I increased the amount of flaxseed oil/day from 1 T to 2 T. My sleep improved: I woke up more rested. Because the sleep effect was now perfectly clear, I thought measuring the effect on my balance would be a good idea. (2) Practice effects were too large. How well I could balance depended on how often I measured my balance. To avoid practice effects, I measured my balance no more than once/day.

I did a baseline period of several days; then I replaced the walnut oil and flaxseed oil with the same volume of sesame oil, which is low in omega-3. I continued this period until the effects seemed beyond doubt. Then I did another baseline period with the original amounts of walnut and flaxseed oil.
Effect of Type of Fat on My Balance
Here are the balance results. Each point is a geometric mean over 15 trials. The bars are standard errors. After one day, my balance got worse with sesame oil. When I returned to the high-omega-3 oils, my balance returned to its baseline level. To measure the clarity of the effect, I compared the 17 baseline days with the last 4 sesame-oil days. This gave t (19) = 4.1. A very clear effect.

I made this graph in a cafe. The person sitting next to me asked what I was working on. I showed her the graph. I explained that I measured my balance as a way of measuring how well my brain was working. The results suggested that the type of fat in my diet affected how well my brain worked. She said the results were very interesting because most people will have diets closer to sesame oil than walnut oil and flaxseed oil. Many people will be interested in these results, she said. I hope so, I said.

I will post later on the background of these results, the questions they raise, and procedural details. If you can’t wait, read the posts in the omega-3 category. If you are interested in doing a similar experiment, please let me know.

How Important is IQ?

Seth Roberts12 Comments

I teach at UC Berkeley. A few years ago I had an eye-opening experience about college teaching and evaluation. I was teaching an undergraduate seminar on depression. For the term project, I allowed/required students to do anything they wanted related to depression, so long as it was off campus and not library research. One student chose to give a talk to a high school class about depression. This would be unremarkable except that she had severe stage fright. The thought of speaking in front of any group terrified her. Every step of planning and doing the talk was very hard. But she managed to do it. In her term-project paper she wrote, “I learned that if I really wanted to, I could conquer my fear, and do what I needed to do” — among the most stirring words I have ever read.

Her work until then — class participation, writing assignments — had put her in the bottom half of the class. Yet her term project showed her to be resourceful (using the term project assignment in a useful way) and courageous (making herself do something that scared her). She chose the assignment that revealed these qualities. Ved Mehta, the writer, who is blind, spent his early years almost entirely within a small school compound. One day he was taken to the beach. He was astonished how freely he could run around. “The school compound . . . suddenly shrank in my mind, like a woollen sock . . . which became so small after [the housekeeper] washed it that I could scarcely get my hand in it,” he wrote in Vedi. As I read my student’s description of what she had done, I saw how narrow and restricted my usual assignments and my usual way of evaluating students had been.

I am sorry that Charles Murray, Bell Curve coauthor, has apparently never had a similar experience. In an op-ed (“Aztecs vs Greeks”) in Thursday’s Wall Street Journal, alas, he made clear his belief that persons with a high IQ are more important economically and culturally than persons with a lower IQ. “We live in an age when it is unfashionable to talk about the special responsibility of being gifted,” he wrote — “gifted” meaning “high IQ.” He used the phrase the gifted. The gifted? If there are thirty or fifty or a thousand different useful sets of abilities, to single out one of them — the one that produces a high score on an IQ test — makes no sense. It’s like referring to the sentence. That makes no sense. There are many useful sentences. We need all of them.

Persons with a high IQ do better at certain jobs, no doubt; but Murray fails to realize that such jobs are a tiny fraction of our economy and that discrimination against any group — failure to help any group develop their skills — is economically damaging because it reduces economic diversity (Jane Jacobs’ point). Murray thinks we should treat high-IQ kids better. He fails to see that it is not people with high IQs who are under-served by the present system; it is everyone else — everyone with other gifts. Plenty of jobs demand resourcefulness and courage, for example, qualities that are probably uncorrelated with IQ, as my student emphasized to me. Both resourcefulness and courage are required to start a new business, which is the most economically important job of all.

Andrew Gelman’s reaction to similar ideas. More about Charles Murray, IQ, and education. A paper of mine about encouraging diversity in learning.

Economics and SLD

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I got a phone call today from a woman in Los Angeles who had some questions about the theory behind the Shangri-La Diet. It was an unusual book, she said.

“What did you like about it?” I asked.

“The cover. It’s warm and inviting,” she said.

I said that was the publisher’s doing, not mine. She also said that it was unusual in that it paid attention to how much things cost. Most diet books don’t, she said. I think my mom would be pleased to hear that.

How Good is Food in Berkeley?

Seth Roberts1 Comment

From an interesting NY Times article about difficult people comes this:

“She’s a superior human being, and she comes from a superior area — Berkeley, Calif.,” Ms. Rothman said. “She has told me many times that there are only two places to get good food. One of them is Berkeley, and one of them is France. And France is only second to Berkeley.”

Huh? I love Chez Panisse but otherwise that makes no sense at all. San Francisco has more great food than Berkeley. So does Los Angeles.

Charles Murray vs. Charles Murray

Seth Roberts8 Comments

The Bell Curve (1994) by Richard Herrnstein and Charles Murray, which argued that IQ is destiny, was the most IQ-glorifying book since . . . well, ever. Now Mr. Murray has taken a big step away from his position in that book, yet he continues to glorify IQ.

In today’s Wall Street Journal, Mr. Murray wrote an op-ed piece (“What’s wrong with vocational school?”) with which I mostly agree. His main point is that for most students, college is a waste of time. As a college teacher (at Berkeley), I have seen that all too clearly. Mr. Murray has an unfortunate way of stating his position. “A four-year college education teaches advanced analytic skills and information at a level that exceeds the intellectual capacity of most people.” I’d put it differently: A four-year college education teaches analytic skills and information at a level that exceeds the interest of most people. I am sure that if my students or anyone’s students were more interested in the material, they would learn it better. That most college students are not interested in the same things as most college professors is a good thing, economically speaking. A healthy economy is a diverse economy; a diverse economy requires a wide range of skills and knowledge, much wider than the narrow skills and knowledge possessed and taught by college teachers. But it is a bad thing for the students and teachers, who are trapped. They have to be there. I feel worse for the students, of course — they are paying to be there.

It isn’t complicated: IQ tests were designed to predict school performance. They do. People with higher IQs do better in school. To believe in the value of IQ is to believe in the school system it reflects. To glorify one is to glorify the other. Now Mr. Murray has taken a step away from one (the school system) but not the other (IQ). Well, nobody’s perfect.

Were I grading The Bell Curve, I would give it a B. The sad truth is that its basic conclusion, that a high IQ is really helpful, is entirely correct. A better book would have replaced the wacky genetic chapter with an attempt to understand why IQ matters so much. In a world where we place less weight on successful completion of college — the world that Murray now advocates — IQ will matter less.

In The Nature of Economies, Jane Jacobs pointed to the stultifying effects of discrimination. “Macho cultures typically have pitiful, weak economies,” she wrote. “Half their population, doing economically important types of work, such as cooking and food processing . . . are excluded from taking initiatives to develop all that work [e.g., open a restaurant] — and nobody else does it, either.” IQ discrimination is also stultifying. If our society did a better job of helping students who are not good at college — helping them find jobs where their abilities shine, instead of wasting four precious years of their lives — the entire economy would benefit.

The Benefits of Theory: Crazy Spicing and B. F. Skinner

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Someone has written me that she is doing well with the Shangri-La Diet by doing only crazy-spicing — adding random spices to everything. She’s not doing anything else — no oil, no sugar water, etc. My reaction is: Take that, B. F. Skinner!

In 1950, Skinner published a paper called “ Are Theories of Learning Necessary?” which revealed that he did not understand the value of theories. In 1977, he wrote a similar paper called “ Why I am not a Cognitive Psychologist,” which showed he still did not understand their value. In the later paper he wrote:

I am equally concerned with practical consequences. The appeal to cognitive states and processes is a diversion which could well be responsible for much of our failure to solve our problems.

The value of crazy spicing would never have been discovered without a theory. Without a theory, you’d never try it. It would never be discovered by accident.

Ripe for Change (movie)

Seth Roberts1 Comment

Last night I saw the excellent documentary Ripe for Change, about new developments in food in California. It is part of a four-part series called California and the American Dream on PBS several months ago (to my horror, I missed it). The showing was hosted by Slow Food San Francisco; I learned about it because I am a member of Slow Food USA, “an organization devoted to preserving traditional foodways” (from their website description).

One of the producers was at the screening and spoke at length about outreach, meaning screenings. PBS misses lots of people, he said. As I say about research, no point doing it if no one learns about it. He can’t post the whole thing on Google Video because PBS owns the broadcast rights for three years. Ugh. First, PBS funds it, then prevents people from seeing it.

Edible Schoolyard

The film covers the Edible Schoolyard in Berkeley (aerial photo above) and attempts in Berkeley to improve school lunches. While writing The Shangri-La Diet, I looked into school gardens as a way to help kids eat better. I visited the Edible Schoolyard, where I was sorry to learn that the ten-year-old program receives $200,000/year in grants (a crucial fact I can’t find on their website) with no end in sight. When I talked with them, they seemed uninterested in reducing this dependency. Not very sustainable, much less repeatable. The Berkeley school lunch program is also in poor shape, although you wouldn’t know it from the film, one of its few shortcomings.

Farmer's Market

In contrast, farmer’s markets are doing great. The crucial step, said the film, was legalization, which happened while Jerry Brown was governor. Farmer’s markets are spreading everywhere, supporting thousands of small farms and artisanal producers, and providing healthier food. (Not to mention their social, entertainment, and educational value.) Could this be telling us something about how to improve school lunches? I think liberalization of the school kitchen laws and allowing lots of small producers to try to make a profit by providing healthy school lunches (giving kids vouchers, say) might go a long way. The current efforts are too top-down and too few brains are involved, I believe.

Before the film there was a short clip of Naked Chef Jaime Oliver trying to improve British school lunches. In what we saw, he was having trouble: the kids wouldn’t eat the food. (Just like in Berkeley.) Jaime Oliver, meet Antonia Demas, whom I wrote about in the last chapter of The Shangri-La Diet.

Yet More about Omega-3

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Perhaps inspired by USA Today, the New York Times discusses DHA, an omega-3 fat sold as a food additive. “Magical or overrated?” is the question posed by the headline. According to Marion Nestle, overrated:

“My experience in nutrition is that single nutrients rarely produce miracles,” said Marion Nestle, a professor in the department of nutrition, food studies and public health at New York University and the author of “What to Eat,” published last year. “But it’s also been my experience that companies will put anything in their food if they think the extra marketing hype will help them sell more of it.”

Single nutrients rarely produce miracles? There is a long history in nutrition of just that: The story of the discovery of vitamins. One single-nutrient miracle after another. Given that history, the claims for omega-3 are plausible. If Nestle has an alternative explanation for the many results that point to the benefits of omega-3, that would be interesting to hear. It wasn’t provided in the article. “Companies will put anything in their food if they think the extra marketing hype will help them sell more of it”? Well, B vitamin supplementation of flour has cut the rate of neural tube birth defects roughly in half, a huge benefit, a huge amount of averted misery. Given that success, it is reasonable to think that other supplementation might also be helpful — to everyone. I discuss derogatory treatment of food companies (”will put anything in their food if . . . hype will help them sell more of it”) in the last chapter of The Shangri-La Diet. Curiously enough, Jane Jacobs once said, you can only change something if you love it.

I have done more self-experimentation about omega-3s and will describe the results in a week or two. Previous posts about omega-3 here, here, here, here, here, here, here, here, here, and here

Robin Hanson on Web Trials (my comments)

Seth Roberts2 Comments

Yesterday I posted Robin Hanson’s comments on web trials. My comments on his comments:

1. I think Robin is right that it would be hard to get most people to allow themselves to be randomized. But I also think it doesn’t matter much. The important thing is to improve on existing methods of evaluation. Randomization of subjects to treatments isn’t an end in itself, of course. The goal is to reach the right answer: Learn which treatment works best. I think if you have what might be called a “level playing field” or a “fair comparison” (the various treatment alternatives are presented “equally” — e.g., as equally likely to work, equally attractive, equally high on a list) it will be hard to imagine how the results will be on average worse than nothing. The site can record data about each subject (age, sex, etc.) and the results can be analyzed using those factors — another way to equate subjects across treatments and to help each person decide what would be best for him or her.

2. Excellent point that web trials could be used for evaluation of any advice. Maybe it would be better to start with a non-health problem. Something where the effects are quick and easy to measure.

3. I like the Wikipedia comparison. All-to-all institutions — institutions that help connect everyone to everyone — are ancient and have been very important. Markets and money may have been the first. If I pay Sam $5 for X, and then Sam pays Peter $5 for Y, Peter and Sam have traded X and Y. Money has made this much easier. Democratic institutions allow everyone to govern everyone. Banks allow everyone to loan money to everyone. Books allow everyone to teach everyone. Wikipedia makes all-to-all teaching much easier. Web trials allow everyone to help everyone solve any problem where data would help. As Robin says, Wikipedia suggests that people will participate in all-to-all institutions when there is no obvious reward for doing so.

Robin Hanson on Web Trials

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I recently asked Robin Hanson, a professor at George Mason University, what he thought of web trials. Web trials are a way to learn how to solve difficult health problems (e.g., acne, obesity). By web trial I mean a web-based collection of data that compares different ways of solving a problem. People with the problem would go to a website, sign up for one of the treatments, follow the directions, and report the results in a standardized format. For example, a site might compare three acne treatments (treatments that anyone can try, such as dietary changes or over-the-counter medicines). The cumulated results would gradually show which treatment works best — a thousand times more efficiently (sooner, cheaper, more easily) than a clinical trial (which no one would finance because there is no profit to be made). Web trials are halfway between clinical trials and the data collection now going on at the Shangri-La Diet (SLD) forums, where people post their progress on SLD.

I asked Robin because he has pioneered a similar improvement: Prediction markets are often far better than what they replace. And his core political affiliation is “I don’t know.”

Here is a summary of what he said.

1. A selection effect is a big concern. Do people wait to report back until after it works? There is always going to be the issue of sampling, selection bias for people who stay with it.

2. How could you get people to allow you (the website) to choose for them which treatment to do? That would be the hard thing. Perhaps the website could say: “would you like to see what our advice for you is?” At most you could get randomization for your advice.

3. It doesn’t have to be restricted to health problems. It could be used to test all sorts of advice. You could just get data about what happens when people do or don’t follow some advice — romantic advice, for example. Very rarely do we have randomization in choices. When we do, we call them natural experiments. In medicine, researchers have used practice variation (variation from one doctor to the next) to look at effectiveness.

4. Perhaps you could get people to commit to this the way they do to Wikipedia. The goal would be: Let’s understand humanity — a noble cause. Let’s be part of a grand project to do this.

Robin blogs at Overcoming Bias. Tomorrow I will comment on Robin’s comments.