Category: ignorance

Meat Consumption and Weight Gain: Health Journalism Done Right

Seth Roberts15 Comments

This article by Eoin O’Connell reports a study in the American Journal of Clinical Nutrition (the top nutrition journal) that found a correlation between meat consumption and weight gain: The more meat you ate, the more weight you gained over five years. Meat is fattening! reported several newspapers.

Mr. O’Connell did something unusual for a health journalist: He thought for himself. I don’t mean he applied a formulaic criticism (e.g., “correlation does not equal causation”). That’s not thinking, that’s knee-jerking. Mr. O’Connell read the paper. And he noticed an interaction: The correlation between meat consumption and weight gain depended on activity level. The study involved about 400,000 people. The researchers put each person in one of four activity levels: inactive, moderately inactive, moderately active, and active. There was a correlation between red-meat consumption and weight only for the two most active groups (moderately active and active). The original article reported that this interaction was significant:

The relation between red meat and weight gain was also stronger in physically active subjects compared with moderately inactive or inactive subjects (P values for interaction = 0.02)

The obvious implication of this interaction, as Mr. O’Connell says, is that meat caused muscle gain. Weight differences between more-meat and less-meat eaters were due to differences in muscle mass. This puts an entirely different spin on the results. The alternative explanation is quite plausible. I once had a grad student who was a vegetarian. When he was an undergrad, he told me, he and his roommate would go to the weight room and do similar sets. His roommate, who ate meat, rapidly gained muscle; he did not. Of course, meat = animal muscle.

Mr. O’Connell continued to the really interesting part of his article:

Perhaps not so surprisingly, the consideration that muscle is a form of weight gain does not appear in the newspaper articles but much more surprising is the fact that it does not appear in the original journal article either.

The AJCN article has fifty authors. Not one of them, apparently, noticed this all-important point! Nor did the reviewers for this prestigious journal. The article concludes: “Our results are therefore in favor of the public health recommendation to decrease meat consumption for health improvement.” No, they’re not, if the more meat, more muscle explanation is correct.

Most prestigious journal. Fifty authors. Huge expense. Total F-up in the sense that the final conclusion is probably wrong. (To be fair, the paper has plenty of value in other ways.) Congratulations, Mr. O’Connell, for noticing.

Sterilities of Scale and What They Say About Economics

Seth Roberts17 Comments

You have surely heard the phrase economies of scale — meaning that when you make many copies of something each instance costs less than when you make only a few copies. Large companies are said to benefit from “economies of scale” — so there is pressure to become bigger. Every introductory economics textbook says something like this.

Here’s what none of them say: The more of Item X made by one company, the more “sterile” Item X becomes, meaning the less Item X is able to spark innovation. Call this sterilities of scale. You have never heard this phrase — I invented it. (I cannot find it anywhere on the Web.) But it is just as obviously true as the notion that when you make more of something you can make each one more cheaply. If 100 widgets are made by one company, there is going to be less innovation surrounding widgets than if 100 widgets are made by 10 different companies. Sterility of Scale 1: When ten different companies make something, more people are studying and thinking about and pursuing different ways of making it than if only one company makes it. Sterility of Scale 2: The more profitable a single item becomes (due to low cost of manufacture), the more pressure not to change anything — not to kill the goose that lays golden eggs. Sterility of Scale 3: The larger the company, the more employees who care only about preservation of their fiefdom (comparing 10 companies of 10 people each to 1 company of 100 people). See how obvious it is that sterilities of scale exist?

The two concepts — economies of scale and sterilities of scale — are equally elementary. But only one is taught. Study of innovation should be 50% of economics but in fact is close to 0%.

This is why Tyler Cowen’s The Great Stagnation is so important — because it begins to point to this great gap. Jane Jacobs did so, but had little or no impact. (At a Reed Alumni Gathering I was seated next to a professor of economics. “What do you think of the work of Jane Jacobs?” I asked her. “Who’s Jane Jacobs?” she replied.) I think human decorative preferences are so diverse (chacun a son gout, no accounting for taste) for exactly this reason, to avoid sterilities of scale. Diversity of preference makes it easier for many different manufacturers to thrive, which increases innovation. For example, diversity of furniture preference makes it easier for dozens of furniture companies to survive, thus increasing innovation surrounding furniture. Clayton Christensen’s The Innovator’s Dilemma describes many examples where large companies were much less innovative than smaller companies — so much so they often went bankrupt. Which suggests sterilities of scale can be fatal.

If there were more understanding that ten small things are going to be more innovative than one big thing, I like to think that scientists would better understand the value of very small research and grant sizes would go down. An illustration of the general cluelessness is someone who wrote to Andrew Gelman complaining that a sample size was only 30.

I started thinking about this after hearing Nassim Taleb discuss economies of scale (e.g., here).

 

Statins Reduce Cholesterol But Not Heart Disease Progression

Seth Roberts26 Comments

The notion that high cholesterol (more specifically, high “bad” — LDL — cholesterol) causes heart disease may be as widely accepted as the notion that humans have caused dangerous global warming. It is much easier to test, however. An excellent study published in 2006 compared two groups of people at risk for heart disease: those given a high dose of statins and those given a low dose. The high dose reducd LDL cholesterol levels; as it was meant to; the low dose did not. But there was no effect on coronary heart disease progression. After a year of statins, persons in both groups had increased their coronary artery calcification score by the same amount — about 25%. Totally contradicting the cholesterol hypothesis.

Regular readers of this blog may remember that after a year of eating butter (half a stick per day), my coronary artery calcification score decreased 24%. Because increases of about 25% are the norm, my score was about 50% less than expected. Decreases are very rare, I was told.

Thanks to Hyperlipid. Statin side effects.

Does Blood Pressure Medicine Always Work?

Seth Roberts3 Comments

Apparently not:

I was a very naughty patient and, after taking Atacand for 135/75 blood pressure (benign essential hypertension was the description) for a number of years on my doctor’s prescription, decided to do a little experiment. That is, I cut back on it gradually, monitoring my BP every day. No change.

 

I eventually got to no Atacand at all and have been there for the past four years, during which time the BP has remained the same as when taking the drug. Now, whether the BP is going to kill me is perhaps a separate question (I seem to be in excellent health at 65) but the Atacand doesn’t appear to have made much difference at all — except for the $600/year it cost me, even after insurance had picked up on some of the expense.

I began to grasp how helpful self-experimentation could be when I discovered that tetracycline, an antibiotic that my dermatologist had prescribed, did not reduce my acne. When I told my dermatologist about the research that revealed this, he said, “Why did you do that?”

Had this person’s doctor told him that Atacand might not work? Clearly not. Did the doctor even know that Atacand might not work? Apparently not, since there was no doctor-guided attempt to find out. Perhaps the doctor who prescribed Atacand would defend himself by saying, lamely, that all he knew is what the drug company told him. I wonder what the drug company knew.

How much money could be saved by stopping the prescription of drugs that turn out not to work? Should all drugs come with a label that says the fraction of patients for whom this drug doesn’t work? It is a warning that is truly needed.

Thanks to Rajiv Mehta.

The Great Stagnation (Part 1)

Seth Roberts16 Comments

Tyler Cowen has written a short Kindle book called The Great Stagnation. I have a lot to say about it. This post is about the context, how it fits into a bigger picture. In a later post I’ll discuss its ideas.

At the end of The Economy of Cities (her favorite among her books), Jane Jacobs said if a flying saucer came to Earth she’d want to know how they avoided stagnation. The main battle in any society, said Jacobs, is not between rich and poor or owners and labor but between those who benefit from the status quo and those who benefit from new ways of doing things. The status quo usually wins, no surprise. And the status quo tends to become more powerful over time, which is why Jacobs didn’t know if profound stagnation could be avoided as a kind of terminal state. When she wrote The Economy of Cities (published 1969), she saw stagnation mounting in the American economy — in transportation, for example. By stagnation she didn’t mean lack of growth; she meant lack of useful innovation, causing problems to stack up unsolved. If you keep doing the same things, but more intensely, you will grow in conventional economic terms (e.g., GDP) but you aren’t solving your problems. Doing more of the wrong thing (e.g., treating all diseases with pills) counts as growth but such growth makes things worse, not better, because bad ways of doing things become more entrenched.

Most people see Jacobs as someone who wrote about cities. She saw herself as someone with new ideas about economic development — especially innovation. Cities are important above all because city people are more innovative than rural people. Tractors, for example, grew out of city inventions (the internal combustion engine, etc.). The same person (same IQ, same wealth) will be more innovative in a city than outside of one.

Stagnation is a major problem at all levels of the economy. A few years ago, a friend of mine who worked at the Chicago Tribune said it was clear newspapers were in trouble long before craigslist. As early as the 1980s, he said, there were bad signs. They were ignored. The people in charge kept doing the same things. Had they started trying new things at the first signs of trouble, they might have found a way out. But they were complacent. By the time they stopped being complacent, it was (apparently) too late. Gone (1999) by Renata Adler, a great book, is about the disastrous consequences of stagnation at The New Yorker. The Innovator’s Dilemma by Clayton Christensen is about stagnation at industry-leading companies, such as DEC, GM, and Microsoft. Failure to innovate enough was what Christensen found when he tried to understand why industry-leading companies frequently lost their lead. Not only do these companies lose their lead, they often go out of business.

How to avoid or recover from stagnation, Jacobs was saying, is the central question of economic life, with no clear answer. Yet it is roundly ignored. In the Berkeley Public Library a few years ago, I picked up an introductory economics textbook for junior colleges, 700 pages long. It had one page — fact-free, poorly-written — about where new goods and services come from. This is typical of the introductory economics textbooks I’ve seen. It reflects the profession as a whole: I estimate about 1% of mainstream economic research is about innovation. It should be half the field.

To study innovation is to study what controls it, what makes the rate of innovation go up or down. Thorstein Veblen (not a mainstream economist) wrote one essay and two books about it. Adam Smith wrote nothing interesting about it, as far as I know, nor did Keynes. I remember nothing interesting about it in The Worldly Philosophers by Heilbroner, including the chapters on Schumpeter and Veblen. There have been no Nobel Prizes about it. (Among the Economics prize-winners, Robert Fogle has done the best work about it, whereas Samuelson’s textbook is a monument to lack of understanding of innovation and its importance.) Ed Glaeser’s new book The Triumph of the City emphasizes that cities boost innovation but Jacobs said this 40 years ago. Because cities tend to grow (increasing innovation as they grow), why do whole societies stagnate? Apparently a countervailing force overcomes the innovative power of cities. I have never heard an economist make this point nor say what the countervailing force might be.

In Collapse, Jared Diamond showed how whole societies collapsed (ran out of food and disappeared) when they failed to innovate enough. Instead of blaming lack of innovation, Diamond blames overfishing, overhunting, soil problems, and so on. His list of “different” causes of collapse is like a list of “different” kinds of paranoia: persecution by the FBI, persecution by the CIA, persecution by the police, and so on. If a society does the same thing over and over, at increasing intensity, eventually it will collapse. The collapse may have many proximate causes.

Tyler does not assume that all growth is good. Perhaps influenced by Robin Hanson, he points out that vast health care spending has done little for American health. Much poorer countries get the same results. When you spend four times as much but get the same results, it implies stagnation. Presumably the 20% we share with poor counties is spent on the oldest stuff. If so, the most recent 80% of growth was worthless and a great deal of it has been a kind of churning, useless research passed off as useful. It entered the health care system, people paid for it, but it didn’t help them. It is entirely possible that some of the expensive health care found in America but not poor countries is beneficial and some of it is harmful.

Tyler sees the forest — a society-wide failure to solve important problems. The tremendous accomplishment of his book is to bring the puzzle of stagnation to mainstream economic attention (“the most talked-about economics book of the year so far” according to this review). I am too far from economics to guess what influence it will have on research, but if mainstream economics becomes even 2% about innovation and stagnation (= lack of useful innovation), that will be great intellectual progress.

For Example?

Seth Roberts2 Comments

My friends know I like examples. My mother has complained I like them too much. Here, via Jonathan Schwarz, is a good example of why I like examples. From a long article by Bill Keller, executive editor of the New York Times:

I’m the first to admit that news organizations, including this one, sometimes get things wrong. We can be overly credulous (as in some of the prewar reporting about Iraq’s supposed weapons of mass destruction) or overly cynical about official claims and motives.

Emphasis added. The lack of an example of being “overly cynical about official claims and motives” speaks volumes about the New York Times’ relationship to those in power.

Preposterous Health Claims of 2010

Seth Roberts1 Comment

Katy Steinmetz, a writer for Time, made a list called “Nutty Health Claims of 2010″ and “2010: The Year in Preposterous Health Claims.” The list of 12 includes:

Preposterous!

Marion Nestle, the New York University nutrition expert, has often said she thinks the health claims made for yogurt are bogus — at least when big companies make them. She recently called Dannon’s claims “a case study of successful marketing”.

Examples of MS Liberation Therapy

Seth Roberts10 Comments

This story from the Globe and Mail describes what happened to ten Canadians who left the country to get liberation therapy for their multiple sclerosis (MS). The therapy consists of widening veins that drain blood from the brain. The therapy does not always work, but it usually does. The improvement is so fast and large — comparable to giving someone with scurvy Vitamin C — that the thing being changed must be the source of the problem.

Mainstream MS researchers missed this completely. The mainstream view is that MS is an auto-immune disease (e.g., according to Mayo Clinic staff). This view would never lead you to the liberation surgery. Doctors not only have the wrong idea, they are unwilling to defend it. A woman in the Globe and Mail story tried to get the anti-liberation argument from neurologists. She couldn’t:

Unfortunately the neurologists are all hysterical. You can’t talk to them.

Remember this the next time someone tells you that ulcers are not caused by stress but are actually caused by bacteria — as several contributors to this EDGE symposium claim.

The vast improvement in understanding of MS came about because someone with the necessary expertise (a professor of surgery) cared more than most MS researchers because his wife had MS. I think this is why my self-experimentation found such different solutions than mainstream science: because (a) I cared more than the professional researchers who studied the subject (e.g., sleep) and (b) I had the necessary expertise to do research. I discuss this here.

Thanks to Anne Weiss.

Epilepsy’s Big, Fat Miracle …

Seth Roberts3 Comments

… is the title of a New York Times Magazine article about the ketogenic diet, a treatment for childhood epilepsy, which I’ve blogged about several times (here, here, here, here, here). It’s a very-high-fat diet. It interests me for two reasons: (a) It connects a high-fat diet with proper brain function, as my self-experiments have done. A curious feature of the ketogenic diet is that it isn’t permanent. After several years the child can go off it. My self-experimentation suggests that Americans eat far too little of certain fats. Perhaps eating enough of these fats would prevent childhood epilepsy. (b) It shows how someone who cares enough — in this case, Jim Abrahams, whose son had epilepsy — can be more effective than professional researchers and doctors. Abrahams rediscovered the diet. He saw its value, the professionals didn’t. I’ve argued that this is part of why my self-experimentation found new solutions to common problems: because I had those problems. I cared more about finding a workable solution than researchers in those areas, who had several other concerns (publication, funding, acceptance, etc.).

The details of the article reminded me of something I learned in the BBC series The Story of Science. For hundreds of years, medical students were told, following Aristotle, that the liver has three lobes. It doesn’t. You might think that examination of thousands of actual livers would have dispelled the wrong idea, but it didn’t. The article contains many examples of doctors ignoring perfectly good evidence in favor of nonsense they read in a book or heard in a lecture. Epilepsy is easy to measure. If a child has 100 seizures per day, and has been having them at this rate for years, and this goes down to 5 shortly after he starts the ketogenic diet, and goes up again when the child goes off the diet, there is no doubt the diet works. As early as the 1930s, this had been observed hundreds of times. This was overwhelming evidence of effectiveness. Doctors ignored it, probably based on the modern equivalent of the three-lobed liver. They complained, according to the article, that there was “no evidence it worked” or that the evidence wasn’t “controlled” or “scientific” (whatever that means). A study published in 2008 “answered doubts about keto’s clinical effectiveness” — as if doctors needed the equivalent of a very-large-type book to be able to read what most of us can read with normal-sized type.

According to the article, “by 2000, more people were asking about keto, but most pediatric neurologists still would not prescribe it” — as if the parents needed the approval of their doctor to try it. You don’t need a prescription to buy food.

Thanks to Tim Beneke, Michael Bowerman, Alex Chernavsky, David Cramer, and Peter Couvares.

The Stupidity of Crowds

Seth Roberts12 Comments

At Tsinghua I am teaching a class called Frontiers of Psychology. The students are reading The Man Who Would Be Queen by Michael Bailey. At one point Bailey mentions what is sometimes called the older brother effect: If a man has one older brother, he is more likely to be gay than if he has no older brothers, controlling for several things. This has been seen many times. In 1962 it was reported that gay men have more older siblings than other men but not until 1996 was it determined that this was due to more older brothers.

Bailey doesn’t mention the strength of the effect. The Wisdom of Crowds by James Surowiecki is about research that found that non-experts can do an excellent job of estimating this or that number (such as the weight of a particular cow) even when they know little about it. Their answers are excellent in the sense that the average of their answers is very accurate. Perhaps my students, who had read two-thirds of Bailey’s book, could accurately estimate the strength of the effect.

I posed the question like this. Suppose that when a man has no older brothers, his chance of being gay is 2.0%. What is his chance of being gay if he has one older brother? I gathered an estimate from every student. The median of their estimates was 8%. The correct answer is 2.7%.