Author: Seth Roberts

My Theory of Human Evolution (osechi)

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Sure, you know that in Japan, New Year’s is the big winter holiday. But did you know that osechi, a kind of fancy bento box, is a holiday tradition? Here are some examples:

osechi example 1

osechi example 2

osechi example 3

The cost, even to an American living in the Bay Area, is . . . surprising:

Just about every major department store and supermarket in Japan now stocks osechi ryori cuisine in December. Most stores offer osechi either as individual dishes or as sets, and many pass out elaborate catalogs to make the selection as easy as pulling out your wallet, which better be stuffed if you plan on ordering osechi as a set. . . . Price is determined by contents and the reputation of the wholesaler or restaurant which put it together. For example, a relatively unknown shop may whip up three 20 square centimeter boxes for ¥22,000 [= $200], whereas Kicho, a famous restaurant in Kyoto offers three circles of the same size for a hefty ¥196,000 [= $1800]. The rest of the sets, ranging anywhere from one to four tiers cost between ¥30,000 to ¥50,000 on average and most Isetan customers buy their ready-made osechi in this price range.

Osechi is another example of how holidays create a market for expensive difficult-to-make things. The Stone-Age predecessors of holidays helped support skilled artists, artisans, and craftsmen, the technological pioneers of the time.

Addendum: Bento boxes inspired the design of the IBM Thinkpad.

How Dangerous is Bariatric Surgery?

Seth Roberts3 Comments

From the abstract of a new paper on the question:

The 1-year case fatality rate was approximately 1% and nearly 6% at 5 years. . . .There was a substantial excess of deaths owing to suicide and coronary heart disease.

Six percent chance of dying within 5 years . . . Your chance of survival is probably better if you are posted to Iraq. On the other hand, another study found a 6% death rate within 5 years for matched obese persons who didn’t have the operation.

The Decline of Fact Checking at The New Yorker

Seth Roberts1 Comment

In the latest New Yorker, an article by Bill Buford begins:

Meat-eaters . . . have more recently had to accept that their diet is probably the source of much of the world’s . . . obesity.

Gary Taubes’ new book Good Calories, Bad Calories argues the opposite. Even if the fact checkers hadn’t read Taubes, surely they knew of the Atkins diet?

Addendum: Buford also blames heart disease on meat. In this talk Malcolm Kendrick notes an inverse correlation between saturated fat consumption and heart disease. Thanks to Dave Lull.

Interview with a Discoverer of the Importance of Omega-3

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Dr. Jorn Dyerberg was one of two Danish doctors who discovered that Eskimos in Greenland, with low rates of heart disease, have much more omega-3 in their blood than Danes in Greenland, with normal rates of heart disease. This was the beginning of the great interest in omega-3s. Here is an interview with Dr. Dyberg. Among his comments:

As for ALA, an omega-3 from plants that is converted in the body to EPA and subsequently DHA, he was unconvinced. In terms of biological effects of DHA and EPA, Dr. Dyerberg said there are many. “We don’t know of any specific biological effects of ALA,” he said.

“Tissue experiments give you an ALA concentration of zero. This omega-3 is either burnt or converted,” he said. “And the conversion is low.”

“If we want the benefits of omega-3, we have to eat them as long chain,” he said, referring to EPA and DHA.

My research — revealing very clear benefits of flaxseed oil, no doubt because of its ALA — shows this is quite wrong.

Thanks to Dave Lull.

Omega-3 and Blood Pressure

Seth Roberts4 Comments

I was surprised to see a chapter in Fish, Omega-3 and Human Health devoted to hypertension. Isn’t high blood pressure caused by too much salt and too much weight? Well, yes, but a special strain of rats used as an animal model of hypertension turned out to have a defect in their immune system. Perhaps high blood pressure is also caused by immune-system over-reaction.

A 1993 meta-analysis of studies of the effect of fish oil on blood pressure concluded:

Diet supplementation with a relatively high dose of omega-3 PUFA, generally more than 3 g/d, can lead to clinically relevant BP reductions in individuals with untreated hypertension.

The sizes of the blood pressure changes:

Weighted, pooled estimates of SBP [systolic blood pressure] and DBP [diastolic blood pressure] change (mm Hg) with 95% confidence intervals were -1.0 (-2.0 to 0.0) and -0.5 (-1.2 to +0.2) in the trials of normotensives, and -5.5 (-8.1 to -2.9) and -3.5 (-5.0 to -2.1) in the trials of untreated hypertensives.

A different meta-analysis reached essentially the same conclusion.

Note the use of fish oil. Fish oil has long-chain omega-3 fats, while flaxseed oil — which I have used in my self-experimentation — has only the short-chain omega-3 fat, which is converted to long-chain omega-3 after you eat it. Fish oil is often considered better because the omega-3s don’t need to be converted. But this way of thinking misses something. Because the omega-3s in flaxseed oil are converted to long-chain omega-3s by enzymes, the amount of long-chain omega-3 in the body rises more slowly (and thus lasts longer) than if you take fish oil supplying the same amount of long-chain omega-3. Flaxseed oil supplies a kind of time-release long-chain omega-3. A long low dose could easily be more potent than a short high dose.

Thanks to Dave Lull.

Israel Ramirez on Gary Taubes

Seth Roberts7 Comments

The theory behind the Shangri-La Diet was inspired by research of Israel Ramirez, which I describe in an appendix (”The Science Behind the Theory Behind the Diet”) to the book. I recently asked Ramirez what he thought of Gary Taubes’ idea in Good Calories, Bad Calories that we are fat because carbohydrate consumption pushes our insulin levels too high. He is especially well-qualified to judge because he has done experiments in which insulin injections induced obesity in rats. His reply:

As I understand Gary Taubes, he has resurrected Atkins’ idea that carbohydrates stimulate insulin which lowers blood glucose and thereby induces more eating. The evidence for this is not very compelling. You can induce overeating with insulin in lab rats but you have to give so much insulin that the animal is in danger of dying. I am not aware of any experiments of this sort in people but diabetics don’t often report being hungry after accidentally giving themselves too much insulin. There are exceptions to this pattern; for people and lab rats, glucose levels tend to fall shortly before eating.

There are clinical trials in people and lab rats showing that high protein, low carbohydrate, diets suppress intake. For people, the effects are modest in the long term, amounting to a few pounds greater loss than for people given a low fat diet at the end of a one year trial. There is some evidence that this weight loss might not be maintained after the first year. Trials showing weight loss on low carbohydrate diets required eating less carbohydrate than that consumed by 99% of lean people.

Cross national and historic data don’t strongly support Taubes. People in countries where traditional high carbohydrate diets are still consumed are often lean, i.e. Japan and China. In recent times, as people in these countries have shifted away from traditional starch diets, frequency of obesity has increased. Intake of soft drinks, on the other hand, does roughly parallel incidence of obesity. I interpret the beverage correlation as a psychological phenomenon but it is also consistent with Taubes.

Even if Taubes were entirely correct about carbohydrates, it would not contradict the idea that learning influences the amount of food you eat. Nor would it mean that extremely low carbohydrate diets are best or easiest way to lose weight; Seth Roberts’ method may still be easier for many people.

The Most Surprising Sentence in Good Calories, Bad Calories

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Gary Taubes’ Good Calories, Bad Calories is overall a very good book, especially in its description of evidence. But there is also this:

Life is dependent on homeostatic systems that exhibit the same relative constancy as body weight, and none of them require a set point.

How does he think body temperature is regulated? Taubes continues:

It is always possible to create a system that exhibits set-point-like behavior or a settling point without actually having a set-point mechanism involved. The classic example is the water level in a lake, which might, to the naive, appear to be regulated from day to day or year to year, but is just the end result of a balance between the flow of water into the lake and the flow out.

No, lakes do not “appear to be regulated” because they do not exhibit anything like hunger or feeling cold. When the water level in a lake is lower than usual, nothing happens to push the level back up. Taubes continues:

When Claude Bernard discussed the stability of the milieu interne and Walter Cannon the notion of homeostasis, it is was this kind of dynamic regulation they had in mind, not a central thermostatlike regulator in the brain that would do the job rather than the body itself.

Michel Cabanac would not enjoy reading this. Whatever Bernard and Cannon had in mind, there is a “central thermostatlike regulator in the brain” that controls body temperature. It makes us seek warmth — take a warm shower, drink hot drinks, put on a jacket — when our body temperature is too low and do the opposite — such as drink cold drinks and eat ice cream — when our body temperature is too high. When our body temperature is too high, we find a warm shower more pleasant than when our body temperature is too low. These changes are obvious — at least, once you look for them — and imply a thermostat in the brain.

Omega-3 and Sports Injuries (more)

Seth Roberts6 Comments

Anonymous found, to his surprise, that his martial-arts injuries healed faster after he started taking flaxseed oil (2 T/day). A comment about Popeye vitamins led him to stop taking flaxseed oil. Within ten days, his gums got worse, and his sports injuries became more painful. He has written again:

After going off flaxseed oil for about ten days and seeing all sorts of negative side effects, I have now been back on it for about ten days (this time with four tablespoons a day instead of two), and I am totally back to where I was before I stopped. Gums aren’t bleeding at all, joints and tendons don’t ache, and I feel great. Anecdotal evidence yes, but very persuasive to me. I have kept taking four tablespoons instead of the previously normal two because I think it increases my mental acuity

Very persuasive to me, too, regardless of what it is called.

Fish, Omega-3 and Human Health

Seth Roberts2 Comments

I ordered Fish, Omega-3 and Human Health (2005, 2nd ed.) by William Lands from Amazon in March. It came a few days ago. It is published by the AOCS Press. AOCS = American Oil Chemists’ Society.

A jewel of a book. Like a research monograph, it has lots of data, graphs, and references; unlike a research monograph, it tries to reach any scientifically literate reader, not just specialists. It has much more about mechanism than other books on the subject. “Health” in the title mainly means circulatory system health (heart disease, strokes); there is also a chapter on the immune system and a chapter on cancer. Almost nothing about mental illness or the brain. Nothing about gum disease.

I read the first edition a year ago. It is a sign of changes in my thinking that I didn’t notice a comparison of epilepsy rates in Eskimos (high omega-3 diet) and Danes (low omega-3 diet) living in Greenland. The Eskimos have twice as much epilepsy. It is the only big negative effect of the Eskimo diet. The epilepsy difference fits something I think now but didn’t think a year ago: omega-3 makes neurons more easily excited. Three observations led me to this: (a) In my choice reaction-time experiments, flaxseed oil caused an increase in anticipation errors. To reduce them, I changed from a two-choice task to a four-choice task. (b) A friend said I have become more talkative, apparently due to consuming much more flaxseed oil/day. (c) I found that flaxseed oil reduces simple RT — latency to press a button when something happens.

The two-to-one epilepsy ratio is the only case where the Eskimos are clearly worse off. The ratios in the other direction are much larger. The Danes had 20 times more psoriasis than the Eskimos (as I noted earlier), and 25 times more bronchial asthma.