Month: January 2007

Michael Pollan vs. Processed Food

Seth Roberts7 Comments

The problem with Michael Pollan’s latest food piece in the New York Times is that it isn’t very . . . nutritious. It doesn’t contain a story with new and interesting facts — like the story of Joel Salatin, a brilliant Virginia farmer, well told by Pollan in The Omnivore’s Dilemma. Instead it contains many broad generalizations, the evidence for which is never given in any detail. Long ago we ate food (i.e., unprocessed food), says Pollan, and it was better for us than the processed food products we eat today. Long ago we listened to stories, say I, and it was better for us than the expert statements on which much of modern journalism is based. If I taught journalism (as Pollan does), I would tell my students the best thing is a story of success (e.g., Salatin) because we can always learn from it. Next best is a story of failure because we can always learn from that, too. Worst is to quote experts (e.g., Pollan quotes Marion Nestle). For two reasons: 1. Experts are often wrong. When they are, it is worse than learning nothing — we are actively misled. 2. Experts — at least in standard journalism — never say the facts on which their claims are based. Even if they are correct, what the reader learns from quoting them is shallow.

Misled by experts, apparently, Pollan repeats Marion Nestle’s recommendation to “eat less” (to reduce obesity). Why it is helpful to repeat failed advice that the rest of us have heard a thousand times is not explained. Nor is it made clear what ancient foodway — Pollan is basically saying we should return to long-ago ways of eating — we would be following if we tried to “eat less.” As far as I know, the answer is none of them.

Several big important stories contradict Pollan’s conclusions. One is the story of B vitamin supplementation of flour and other processed food, which greatly reduced neural birth defects. I heard a dean of a public health school tell a room full of new students that this one advance, which averted so much suffering, fully justified all the money spent on schools of public health. I agree. Processing food is not always bad. Sometimes it can be very good. When you process food based on a correct theory, that often happens. Food sterilization, refrigeration, and preservation via additives — all based on a correct theory, the germ theory of disease — have had many benefits. It’s when you process food based on a wrong theory — such as the theory that fat causes obesity — that you can easily do more harm than good.

There is no turning back. We can’t avoid processed food. To move forward, we need better theories to guide the processing. Anyone who reads this blog regularly knows I think ancient foodways are a good source of evidence with which to build theories (e.g., Weston Price) but of course there are many other good sources of evidence.

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Usually CISSP professionals prefer doing N10-003 as it helps them in their SY0-101 later. A small number however is content with 70-649 too.

Saul Sternberg on Research Design

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No one has had more effect on how human experimental psychology is done than Saul Sternberg, a retired professor of psychology at the University of Pennsylvania. In the 1960s he introduced a memory-scanning task in which the subject responds as quickly as possible whether a probe item (usually a digit) is on a short memorized list. The main measure was reaction time (RT) — the time between when the subject saw the item and his response (”yes” or “no”). The linearity of the RT-vs-set-size function and the equality of the “yes” and “no” slopes suggested that search of the memorized list was serial and exhaustive (exhaustive meaning that the whole list was searched even when the target was found before the end). Before this heavily-cited work (published in Science and American Scientist), RT experiments were rare; after it, they were common.

SR: Where did your first ideas about research design come from?

SS: While I was a graduate student [(at Harvard in the 1950s)] I read Williams James’ Principles of Psychology, which increased the curiosity I had developed about mental processes from my introspections. Although I wasn’t working on those questions when I was a grad student, I became interested in them. I wrote down ideas for experiments — experiments on short-term memory, for example. Experiments to answer questions about things I observed about my mental processes while engaged in writing and reading and other everyday activities. At the time I was doing theoretical work on learning models that apply to both animals and people. [Stochastic Models for Learning by Bush, Sternberg’s advisor, and Mosteller was published in 1955.] I didn’t collect much data as a graduate student, after my interests turned to learning models. Earlier I had collected data in social psychology. I recall putting a lot of effort into an experiment on small group interactions. What was novel was that we were recording interaction events in real time by punching IBM cards.

I learned how to be an experimental psychologist during my first teaching appointment that started in 1960 at Penn, when I co-taught a laboratory course on experimental psychology. I taught it with Bob Teghtsoonian and Jack Nachmias, who became my teachers. In those days, many students took a lab course after Psych. 1. The course required us to develop experiments for undergraduates to do. Questions that arose in those experiments went beyond available knowledge. And these questions led to some actual research. In 1962 Bob Teghtsoonian and I gave a paper at EPA on all-or-none versus gradual learning of response components, in which we reported tests of two models. And in 1963 Jack Nachmias and I gave a paper at the Psychonomic Society in which we reported our application of signal detection theory to data on recognition memory that we had collected.

SR: You started your memory-scanning experiments after that course?

SS: That’s true. I started them during my second year at Penn. I was still working on learning models. I was also supervising a graduate student whose research had to do with short-term memory. Not RT experiments, however. What got me interested in RT experiments was work by Ulric Neisser measuring search times. He measured visual search times as a function of number of targets for which you search. [Neisser’s subjects searched a visual display — e.g., of digits or letters — for the presence of one or more digits or letters. The main measure was how long it took to search the whole display.] It’s like a crude RT experiment. You’re not measuring how long it takes to make one decision, you’re measuring the time to make many decisions. I was skeptical about his conclusions so I thought it would be worth measuring how long it took to make a decision about one visual item. That led to the memory-scanning experiments. I did several of them, to help choose among alternative interpretations, before I reported the results. I gave a paper on those experiments at the meeting of the Psychonomic Society during the summer of 1963.

Previous post in this series: Brian Wansink on research design.

Amory Lovins on Self-Experimentation

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Amory Lovins is an engineer with many new ideas about how to save energy. In a recent interview, he made these comments relevant to self-experimentation:

[Edwin Land] said that people who seem to have had a new idea often have just stopped having an old idea.

Experimental psychology began with self-experimentation — the memory research of Ebbinghaus. I stopped having the idea, dating from around 1910, that there was something wrong with self-experimentation.

Small resources like solar cells or wind turbines have less financial risk than giant power plants that take many years to build.

Self-experimentation, the smallest and cheapest research of all, has less financial risk than other research, including large experiments that take years to do.

Article about Amory Lovins

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

Seth Roberts1 Comment

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?

Bruce Springsteen on Education

Seth Roberts5 Comments

In an interview, Bruce Springsteen said:

I wasn’t quite suited for the educational system. One problem with the way the educational system is set up is that it only recognizes a certain type of intelligence, and it’s incredibly restrictive — very, very restrictive. There’s so many types of intelligence, and people who would be at their best outside of that structure [get lost].

Yes! That’s what I’m saying here, here, and here. The quote is from David Shenk’s great new blog about talent and how to nurture it.

Secrets of a Successful Blog (part 3)

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Brad DeLong, Berkeley economics professor and very popular blogger, on what makes a blog successful:

1. First-mover advantage. Brad’s was one of the first economics blogs.

2. Regularity of posts. Brad said he writes several posts during one hour in the evening to be posted at intervals the next day. At least that is the ideal, he said.

3. Communicate effectively on things people want to learn about.

Tyler Cowen and Aaron Swartz on this topic.

I learned this last week when Aaron Swartz and I stopped by Brad’s office. I had put the odds of him being there at 50 to 1. Speaking of supposedly-low-probability events, yesterday at the Berkeley Farmer’s Market someone recognized me from the photo on my book. The previous day I had said that would never happen.

Self-Experimentation = Old Buildings

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In The Death and Life of Great American Cities, Jane Jacobs wrote, “Old ideas can use new buildings, but new ideas need old buildings.” New ideas need old buildings because old buildings are cheap. New ideas cannot be expected to be especially profitable, or profitable at all, at first. This is why self-experimentation should have a permanent place in the ecology of science: It provides a cheap way to develop new ideas.

Science in Action: Omega-3 (materials)

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Self-experimentation is for everyone just as blogging is for everyone. You don’t need fancy equipment to be an interesting blogger and you don’t need fancy equipment to do interesting self-experimentation — at least I think my recent omega-3 results are interesting. Here are the easy-to-find materials I used:

1. To measure my balance, I used a bamboo cutting board ($15), a 0.5-inch pipe plug ($1), a booklet with about 20 pages (free), and a stopwatch ($10). Here they are:
Balance-measurement equipment

This shows the size of the pipe plug:

The pipe plug up close

I put the booklet on the floor and put the pipe plug in a cut-out hole in its center. The hole goes about halfway into the booklet (e.g., 10 pages out of 20).

Assembly of the balance-measurement equipment: Step 1

Then I balance the cutting board on top of the pipe plug:

Assembly of the balance-measurement equipment: Step 2

I stand on my right foot on the cutting board; the measure is how long I can balance on it before my left foot touches the floor.

2. To vary the amount of omega-3 in my brain, I used these oils:

The oils I used

Walnut oil and flaxseed oil are high in omega-3 fats; sesame oil is low.

If you are interested in doing similar experiments, feel free to contact me.

Science in Action: Omega-3 (background)

Seth Roberts4 Comments

The omega-3 story began with the circulatory system. In the 1960s, two Danish scientists wondered why Eskimos rarely die of heart disease. Could the answer explain the sharp decrease in heart disease mortality in Norway during World War II? In spite of this promising beginning, the heart and mortality benefits are still not clear. A 2006 meta-analysis of heart disease studies concluded that “omega 3 fats do not have a clear effect on total mortality, combined cardiovascular events, or cancer.”

You can find lots of recommendations to consume omega-3 fats in various forms — fish, supplement, and so on. On the other side, Marion Nestle, the author of What To Eat, seems to believe the advantages claimed for omega-3 are “ hype.” Most researchers are less certain. From a recent New York Times article about Martek, a company that makes an omega-3 food supplement:

“A lot of the claims made for DHA [a form of omega-3] are in the realm of hypotheses,” said David Schardt, senior nutritionist at the Center for Science in the Public Interest, an advocacy organization based in Washington. “They are certainly worth pursuing, but there’s not yet enough proof to warrant telling people to go out of their way to take DHA.”

The exceptions, Mr. Schardt said, are people with a history of heart disease and premature infants, who need an extra boost of DHA for proper brain and eye development to compensate for their early exit from the womb.

Martek’s scientists, when pressed, generally agreed with Mr. Schardt. The data showing any health benefits of DHA beyond those related to the heart or premature infants, while encouraging, is not quite conclusive, they say.

The typical experimental study of omega-3 takes two groups of people with a pre-existing problem, gives one group omega-3 and the other group a placebo, and measures outcomes several months later. A 2005 study in Pediatrics, for example, compared two groups of children (n = about 60/group) with Developmental Coordination Disorder. Most of them had ADHD. One group was given an omega-3 supplement; the other group was given a placebo. The children were tested before treatment and after three months of treatment. (The reading, spelling, and behavior scores of children in the supplement group improved more than the scores of children in the placebo group.) Studies like this are hard.

In summary, there is considerable uncertainty about the effects of omega-3; and the methods used to reduce that uncertainty are slow and difficult. This is why self-experimentation might help.

My recent data. The Queen of Fats (2006) by Susan Allport, a science writer, is an excellent introduction to the subject.

The Half-Measure

Seth Roberts1 Comment

Today I attended a two-hour class associated with the San Francisco Fancy Food Show called “Tradition + Technique + Terroir = Taste of European Traditional Foods.” The class covered four hams, five cheeses, three olives, and two beers. The general idea was to explain how great these foods are so that the students — mostly food retailers — can successfully sell them. One of the cheeses was a cheddar. There is a town in England called Cheddar, I learned.

I asked a question: “When an American cheese maker makes a cheese and calls it a cheddar, what are they doing?”

“It doesn’t taste the same!” said the American retailer who was in charge.

This irritated me. “When an American cheese maker makes a cheese and calls it a cheddar, it isn’t a joke,” I said. “There’s a reason for it.” Then the process called cheddaring was explained.

The people who make English cheddar cheese (the original), the people who make Greek feta cheese (the original feta), and many other food producers would like no one else to be able to use the names cheddar, feta, etc. Inside the European Union, that is often the case: Only Greek feta can be called feta, for example. A new EU program labels foods with “Protected designation of origin” or “Traditional specialty guaranteed” as a way to help consumers know that they are getting the traditional original product.

This is a half-measure. I am in favor of anything that helps preserve the diversity of what we eat, so I am in favor of this program. I am in favor of telling the stories behind English cheddar, Greek feta, and so on. But this sort of thing is a half-measure because the best way to ensure the survival of a food is to ensure it tastes better than similar foods. A labeling program does not do that. Not in the slightest. Perhaps future efforts should be focussed on how to make customers more discriminating. Here is the truth: Traditional products often taste very good. Here is the half-truth: They taste very good because they are traditional. Here is the (implicit) lie: Non-traditional products taste worse because they are non-traditional.