Category: nutrition

The Israeli Paradox

Seth Roberts3 Comments

You’ve heard of the French Paradox (140K Google hits), the fact that the French have little heart disease in spite of a diet high in saturated fats (the supposedly bad fats). You haven’t heard of the Israeli Paradox (<1K Google hits), which may be more important. (The French Paradox may be an historical accident.) The Israeli Paradox is the fact that Jewish Israelis have very high rates of heart disease, diabetes, and cancer in spite of a diet low in total fat, high in polyunsaturated fats (the supposedly good fats), and low in saturated fats.

The best guess is that the Israeli Paradox is due to a high intake of omega-6 fats (from soybean oil). Non-Jewish Israeli citizens have rates of heart disease, diabetes, and cancer roughly half the Jewish rate. The non-Jews consume lots of olive oil (low in omega-6) rather than soybean oil. This is not an omega-3 effect; olive oil is low in both omega-3.

“Replacing saturated fats with unsaturated fats [such as omega-6] is a safe, proven, and delicious way to cut the rates of heart disease,” wrote Walter Willett, the Harvard epidemiologist, in Eat, Drink, and Be Healthy (2001, p. 71). The Israeli Paradox shows that this way of reducing heart disease is anything but safe and proven.

An Unexpected Benefit of Self-Experimentation

Seth Roberts2 Comments

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.

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.

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.

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.

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

Someone Has Been Reading This Blog

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According to this USA Today article, “omega-3 is in”. That is, in many new food products to be introduced in 2007, such as a new orange juice. Omega-3, says the article, is “the hot ingredient” and “the miracle food.” The article delicately calls omega-3 a “fatty acid” rather than a fat. My many posts about omega-3 include this and this. More to come.