Month: August 2007

Science in Action: Omega-3 (VSE)

Seth Roberts17 Comments

VSE = Very Short Experiment. After VSL (Very Short List). I did this experiment yesterday. It took the whole day but the results were clear by noon.

At about 7 am I took 4 tablespoons of flaxseed oil (Spectrum Organic). I measured my mental function with a letter-counting test. Here is what happened.

RT results

My reaction times decreased 2-3 hours after drinking the flaxseed oil. Over the next 6-8 hours they returned to baseline.

For cognoscenti, here are the accuracy data:

accuracy results

Accuracy was fairly constant.

These results resemble earlier time-course measurements (here and here). What pleases me so much is not the confirmation — after the earlier two results I had found the dip a third time and had found that olive oil does not cause a dip — but how fast and clear the main result (the dip) was. I could have done a mere four tests (7, 8, 10, 11 am) and found interesting results — I knew that the 8 am test was too early to see a difference so it would have been two tests “before” and two “after”. Six hours of testing can say something interesting about what we should eat and how to make our brains work best.

If you’ve been reading this blog you won’t be surprised that flaxseed oil helps; what’s new is how easily I can test a big wide world of foods. Salmon, trout, herring, fish oil, olive oil, canola oil, walnut oil, soybean oil, and so on. All sources of fat. Not to mention eggs.

I take 4 tablespoons of flaxseed oil most days; I am not suffering from too little omega-3, as most people are. This improvement is on top of the improvement produced by getting enough omega-3 most days. If I stopped taking flaxseed oil, my mental function would slowly get worse, as an earlier experiment (here and here) showed.

Can Professors Say the Truth? (radio show)

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Part of today’s KQED Forum program with Michael Krasny was devoted to the attacks on Michael Bailey and his book. Here is the webpage. Joan Roughgarden, a professor of biology at Stanford, was one of the guests. After Bailey gave a talk at Stanford in 2003, Roughgarden wrote an op-ed in the student newspaper that contained the following sentence:

To many observers, Bailey appears to be a rather dumb, stubborn, dense and possibly deceptive regular guy with some experience in locker-room humor.

This sort of comment would go over poorly on KQED, so what would she say? It turns out that she calls Bailey’s book a “fraud.” It is fradulent because it is not “science” — by which she means a scientific article — in spite of having the word science in the title. Apparently Roughgarden thinks that if you write a book about science it is fraud to use the word science in the title. She also complains that Bailey uses stories based on transsexuals he had met to illustrate Blanchard’s theory. She calls those stories Bailey’s evidence for the theory, ignoring the evidence in Blanchard’s papers. This is not quite the incisive criticism we might expect from a Stanford professor.

A Novelist on the Aquatic Ape Theory of Evolution

Seth Roberts1 Comment

Plausibility of the Aquatic Ape Theory of Human Evolution is one reason I started studying the effects of omega-3s. Novelist Elizabeth Bear doesn’t like it:

[Doris] Lessing appears to have drawn her background from Elaine Morgan’s notorious pseudoscientific tome, The Descent of Woman (1972), which argues that human evolution was shaped by a seal-like return to the sea. Crackpot theories can make for great fiction but in this case . . .

That I found beneficial effects of omega-3s many times supports the “crackpot” theory.

Does Walking By McDonald’s Make You Fat?

Seth Roberts6 Comments

Few people have used the theory behind the Shangri-La Diet more successfully than Tim Beneke, an Oakland journalist. I put before and after photos of him — before and after he lost about 100 pounds — on the front page of the proposal for The Shangri-La Diet. He writes:

It’s very clear to me this summer that it’s much easier for me to go tasteless and only consume the mush if I don’t go to Berkeley, and just stay home in my apartment (except going for my neighborhood walk). And it’s not merely a matter of behavior. When I go to Berkeley and walk near places where I am accustomed to eating (and tasting) — mostly restaurants, sandwich shops and coffee houses — I actually experience more hunger and must consume more mush to satisfy hunger than if I stay home.

I’m not surprised that auditory and visual signals for food cause hunger. There are lots of conditioned cravings like that. Tim goes on to wonder if these learned signals for food raise the body-fat setpoint, as the theory behind the Shangri-La Diet says that food-associated flavors do. If you walk by your favorite bakery every day, will you weigh more than if you don’t?

I always lose weight when I travel in foreign countries. I’ve attributed this to unfamiliar food. But could unfamiliar places also play a role?

In 1973, Edward Zamble, a professor of psychology at Queen’s University, Kingston, Ontario, published an experiment very relevant to this question. He divided rats into two groups. Both group got their daily meal at random times. For one group, the meal was preceded by 30 minutes of light; the light went off before the food was available. The other group was exposed to the same amount of light but the light bore no relation to when they were fed. The rats with signaled food ate more and weighed more than the rats with unsignaled food.

I knew of this experiment — and often mentioned it — before I came up with the theory behind the Shangri-La Diet, but I never connected them. Thanks, Tim.

Science in Action: Omega-3 (time course 2, with eggs)

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Last week, I tried to measure again the time course of flaxseed oil’s effect on how well my brain works. As before, I used a letter-counting test. The test consists of trials where I see a four-letter display such as ECQZ and type as quickly as possible how many letters from ABCD are among them (in this case, 1). 200 trials per test, about one test per hour.

On Tuesday, about 3 pm, I drank 4 tablespoons of flaxseed oil. Here’s what happened:

graph of flaxseed oil results

The flaxseed oil seemed to reduce reaction time. The maximum reduction was 40 milliseconds, which happened 2-3 hours after drinking the oil. The effect was gone about 6 hours after drinking it.

The next day I expected my scores to be close to the pre-drink baseline. At 5 pm my score was much lower than expected. The difference from baseline was close to the effect of flaxseed oil; moreover, it disappeared at close to the same speed as the flaxseed-oil effect disappeared.

Although surprising, this had a plausible explanation: About three hours earlier, I had eaten three eggs from grass-fed (also called range-fed) chickens. (More precisely, I had had one egg in a smoothie at 11 am and two scrambled eggs at 2 pm.) Such eggs are believed to be high in omega-3. A 1992 paper compared the amount of omega-3 in supermarket eggs and eggs from a Greek farm, where the chickens ate “fresh green grass leaves and wild plants including purslane . . . fresh and dry figs, barley flour . . . insects of all kinds.” The supermarket eggs had little omega-3; the Greek eggs 10 times more.

My eggs came from the Bay Area Meat CSA, run by Tamar Adler (tamareadler a/t earthlink.net), a chef at Chez Panisse, who is looking for new members. Pickups in Berkeley and San Francisco.

Jane Jacobs and Traffic Tickets

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Rexford Township, Michigan, has started to pay police officers according to the number of tickets they write. In Systems of Survival, a book about moral systems, Jane Jacobs criticized something similar: ticket quotas for police. Treating guardians (such as police) as if they were in commerce doesn’t work well, she wrote. There are two ways of making a living (taking and trading). Both have value, but they need to follow different rules of conduct (which we may grandly call morals) to work well.

What Goes Around Comes Around

Seth Roberts2 Comments

One of my favorite stories in Discover Your Inner Economist by Tyler Cowen:

During one riot in Michigan, one woman sold stones to rioters. . . . Small stones went for $1, larger stones brought in $5 a piece. Most of the rocks were thrown at police. . . . The woman claimed that she collected about $70 from her efforts, but she stopped when she was hit by a rock herself.

A perfect illustration of the title of this post.

What makes a good story? Perhaps 1. Hero. 2. Villain. 3. Struggle. 4. Details. 5. Humor. 6. Message. 7. Goodness is rewarded or sin is punished. 8. Truth (it actually happened). The rock story has six of these.

Nutritional Psychology: A Gaping Hole Where a Field Should Be

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Yesterday I attended the annual convention of the American Psychological Association (APA) in San Francisco. I was also measuring (again) the time course of omega-3 effects. The exhibits hall was full of books. I picked up three introductory psychology texts to see what they said about nutrition. None of their indexes listed nutrition; apparently they said nothing about it. None of the hundreds of books I saw was about nutrition — that is, about how to nourish the brain. Yet the APA is mainly about mental health.

It’s not just APA. At Berkeley, I’ve attended dozens of talks in the Nutrition Department. I have never seen another psych professor or grad student at any of them. Nor have I seen a nutrition professor at any Psychology Department talk. Both disciplines have Annual Review series. In last seven years, there hasn’t been a single article in the Nutrition series about behavior or cognition (aside from eating) nor a single article in the Psychology series about nutrition (aside from an article about weight control).

Sometimes interdisciplinary is hard. Cognitive science has tried to unite computer scientists with linguists and philosophers and psychologists. That’s hard because computer scientists are engineers, not scientists, and philosophers are neither. But nutrition and psychology are both experimental sciences. Nutrition is an independent variable (food), psychology a dependent variable (behavior). They naturally go together, especially if you are concerned with mental health.

Now and then someone will study how Disorder X responds to Nutritional Treatment Y — how depression responds to omega-3, for example. Better than nothing, absolutely, but not the best approach. By the time something is broken it is likely to be (a) a mess and therefore hard to measure and (b) hard to put back together. If you want to learn how a car works, should you study a car that works or a car that doesn’t work? The answer isn’t obvious, at least to cognitive psychologists, because for half a century they mainly studied how memory, perception, etc., failed. In the 1960s, Saul Sternberg taught the rest of the profession a better approach — namely, study a car that works. Sternberg made popular the kinds of experiments usually done today: reaction time experiments with easy problems that subjects almost always get right. My omega-3 research has illustrated the truth of Sternberg’s general point. I found much clearer effects of flaxseed oil on easy tasks (easy arithmetic, an easy memory task) than on a difficult task (digit span). A better way to learn how food affects our brains will be to study the effect of food on healthy brains. Such experiments will be much much easier than studying people who are depressed, children with ADD, schizophrenics, autistic children, drug addicts, and so on. I’m sure that the conclusions from healthy brains will generalize to malfunctioning brains, just as all cars — working or broken — work the same way.