Category: ignorance

Avocado Raises Blood Sugar

Seth Roberts17 Comments

Tim Lundeen writes:

We [Tim and his partner, Alexandra] first noticed that eating avocados raised our blood glucose when we were on a low-protein/low-fat/high-fruit nutrition plan. After 1/4 avocado each, we would both have fasting glucose of 95-99 instead of 80-85, with the effect lasting for about 4 days. It was quite repeatable, so we stopped eating avocados. We speculated at the time that it was due to the omega-6 content of the avocado fat.

We just tried avocado again with more typical nutrition, with about 25% protein, 25% fat, 50% carbohydrate with very low fructose, thinking that because we were eating more fat the effect might not be so pronounced, but saw the same elevated fasting blood glucose as before.

After some more research, we found out it is because avocados contain a sugar called mannoheptulose, which causes temporary dysregulation of blood sugar.

Mannoheptulose was first isolated in 1917. Mannoheptulose has been proven to be present in many foods, but is found most abundantly in the avocado (La Forge 1916-1917). In 1957, the first research was published in the Archives of Biochemistry and Biophysics (Volume 69, page 592), suggesting that avocado extract blocked normal insulin secretion. In 1963, it was demonstrated that avocado extract blocks glucose-stimulated release of insulin (Nature, Volume 197, page 1264). By 1967, low doses of avocado extract were found to inhibit both pancreatic secretion and synthesis of insulin without eliciting measurable hyperglycemia (high blood sugar) (Nature, Volume 214, page 276). This finding was significant because it demonstrated that a controlled dose of avocado extract could suppress pancreatic production of insulin without inducing a diabetic state. [https://www.health-marketplace.com/p-Obesity-3.htm]The problem with this is that your cells don’t absorb nutrition because insulin is reduced, so we have strong cravings for food, feel extra hungry all the time, and have been eating about 50% more calories to feel full. The net effect is not a good feeling…

This makes sense. And it is methodologically interesting. Spending zero research dollars, Tim and Alexandra learned something important about blood sugar control that the rest of the world seems not to know. (Except perhaps the researchers who did the avocado extract research.) None of the research articles they mention make clear the practical significance of the effect. To say that avocado extract does X doesn’t tell you how much avocado you need to get the effect.

When I google “avocado” and “blood sugar” (together), the first page of links all claim, at least at first glance, that avocado lowers blood sugar. But that’s just the internet. (Although Google is supposed to put the most reliable links at the top.) Then I went to the most authoritative possible source on what we should eat: the American Journal of Clinical Nutrition. I found only three articles that mention avocados in their title or abstract. None was about this effect. I also looked in Eat Drink and Be Healthy by Walter Willett and the Harvard School of Public Health. Nothing about this effect of avocado.

A Smug Professor

Seth Roberts23 Comments

The Chronicle of Higher Education website has a blog about “ideas, culture, and the arts [that] features some of the best minds in academic and policy circles”. One of the bloggers — Gina Barreca, a professor of English and Feminist Theory at the University of Connecticut and a humorist — wrote about being older than her students:

I think about the fact that my students and I no longer listen to same music or revere the same actors; I wonder about the implications of the fact that even some of the smart ones like I Hope They Serve Beer in Hell.

I pointed this out to Tucker Max (author of I Hope . . . ). He replied:

I like how she implies that some of her students are stupid. Great prof.

I thought that was a great point. I asked if I could use it on this blog. He agreed, and added:

The other thing about her statement is that she implicitly scoffs at the notion that someone smart could–gasp–DISAGREE with her. It doesn’t even occur to her that she might be wrong, that her worldview might be the one that needs examining. To her, nothing legitimate can exist outside of her prejudices and opinions. Even the idea that it could is rejected out of hand.

I replied:

Yeah, she hasn’t read your book but it must be ridiculous. Of course. I praised the film Gladiator (pre-Oscar) to someone I knew and she said, to a friend, that this made me an inferior person. Because Gladiator was popular, it must be bad. If I liked it, there was something wrong with me.

Tucker replied:

Exactly–the idea that THEY might be wrong doesn’t even occur to them. Like it’s not even in the realm of possibility.

These are the same people that Nassim Taleb rails against, and the same people who read Socrates, and completely miss the point, but still praise it because they think they’re supposed to. And these are the people that the internet/the age of connectivity is destroying. Because you can’t hide behind status anymore. Results are measurable, and everyone is on the playing field now.

I agree.

Unnoticed Conflicts of Interest

Seth Roberts10 Comments

Gary Taubes pointed to this PNAS paper about climate change and noted that one of the authors, Stephen Schneider, had a big non-financial conflict of interest: If it turns out the whole argument is wrong, he looks like a fool. The accompanying statement (“The authors declare no conflict of interest”) is, if taken to mean the authors have no conflict of interest, wildly inaccurate. Readers unaware of Schneider’s history wouldn’t know this.

I came across a similar example today. A reader of this blog wrote extensive criticisms (here and here) of the idea that prenatal ultrasound may cause autism. He believed Caroline Rodgers, my source for that idea, misrepresented the evidence. In particular, Rodgers pointed to a study that found ultrasound disturbed neuronal migration in mouse fetuses. She said it supported her idea. The reader disagreed, saying,

The bottom line for me is that Dr. Rakic (from the mouse study) clarified, “Our study in mice does not mean that use of ultrasound on human fetuses for appropriate diagnostic and medical purposes should be abandoned. Instead, our study warns against its non-medical use.” Yes. Okay. No more boutiquey, keepsake ultrasounds. Great. But for Rodgers to skew this data (along with the FDA’s and others’) into claiming that ultrasounds under the care of an Obstetrics professional (and for medical use) are causing autism is disingenuous at best, unethical propaganda for the Midwifery Way at worst.

The reader is a professor who teaches composition. Maybe an English professor. He or she takes Rakic seriously, where I completely ignore his statement because of a conflict of interest. If Rakic questions “appropriate” ultrasound, he will be attacked in many ways, making his life unpleasant. I have no idea whether this swayed Rakic, but he would be only human if it did.

Of course developing neurons are unable to distinguish appropriate and inappropriate ultrasound. Rakic’s statement is ridiculous as Rakic and all insiders (neuroscientists) know, I believe. All insiders know that there are dozens of examples where findings from mouse brains have turned out to be true for human brains, in spite of the many differences between them, and that there are thousands of grant proposals in which mouse brains are claimed to be a worthwhile model for human brains. All insiders know this, realize the pressure on Rakic to say what he said, and, like me, just ignore it. As far as I can tell, Rakic pays no price for misleading outsiders because the outsiders don’t know they are being misled. (Just as with political lobbying: the public doesn’t understand what’s happening.) The composition professor doesn’t know this, as far as I can tell.

Rodgers is not claiming that ultrasounds “are causing autism”. She is saying they might cause autism, that there are several reasons to think so, and therefore (a) the ultrasound-autism idea deserves further scrutiny and (b) ultrasounds should be avoided as much as possible until more is known.

The FBI Gets It Backwards

Seth Roberts3 Comments

The FBI recently sent a letter to the Wikipedia Foundation saying it should take down an image of the FBI shield — that is, a picture of an FBI badge — and threatened legal action. Supposedly the Wikipedia Foundation was breaking a law by posting it.

The Wikipedia Foundation responded that

The law cited in the F.B.I.’s letter is largely about keeping people from flashing fake badges or profiting from the use of the seal

If nobody knows what an authentic badge looks like it becomes easier to fool people with a fake badge.

Premier of Canadian Province Gets Involved in MS Research

Seth RobertsLeave a comment

How strange:

I n a striking departure from his political counterparts across the country, Saskatchewan Premier Brad Wall says his government will finance clinical trials of liberation therapy, a contentious experimental procedure for multiple sclerosis patients.

Of course, the heads of provinces don’t usually get involved in research at this level of detail. However, “Saskatchewan has the highest rate of MS in the country,” says the article.

In Part 5 of The Story of Science (BBC), Michael Mosley, the presenter, said that for hundreds of years medical students were shown a human liver and told it had three lobes. They were told that because that’s what Galen had said. However, human livers do not have three lobes. As the students could see. Mosely is a doctor. “When I was a medical student,” said Mosley, “there was tremendous pressure to conform.” MS researchers have said for a long time that MS is an autoimmune disease. Could this have been as misleading as Galen’s description of the liver?
Thanks to Anne Weiss.

The Future of Dentistry and Experimental Psychology?

Seth Roberts4 Comments

Rereading an old post, I found this:

Today I had my teeth cleaned and was told my gums were in excellent shape, better than ever before [due to flaxseed oil]. They were less inflamed than usual. “What causes inflammation?” I asked. “Tartar,” I was told.

I believe that reddish gums are a great sign (so easy to see) that overall your body has too much inflammation, putting you at higher risk for many common diseases. (Perhaps due to too little omega-3, which the body uses to make an anti-inflammation hormone.) Every day my dentist measured, or at least saw, a great correlate of health (the redness of his patients’ gums) and failed to notice. It’s like failing to notice an oil field under your property. If dentists became experts in measuring gum redness and helped their patients lower overall inflammation, the public health contribution would be great. (Writing this makes me wonder why I haven’t become skilled at measuring the redness of my gums.)
Experimental psychologists are in a similar position. I believe brain health is closely correlated with health of the rest of the body. In other words, the foods that make the brain work better make the rest of the body work better. I discovered the anti-inflammatory effects of flaxseed oil because it improved my balance. The brain is much easier to study (via behavior) than the rest of the body — it’s a model system for the rest of the body. Experimental psychologists are as unaware of their good fortune as dentists. By using their skills to figure out how to have the healthiest possible brain, they could make a great contribution to human welfare.

Nassim Taleb Interview

Seth Roberts5 Comments

Nassim Taleb has honed his replies to common questions:

Why did economists get the crisis so wrong?
That’s like asking why fortune-tellers don’t get things right. Their tools don’t work, but they continue to use them. And the Nobel committee gives prizes to people who aren’t scientists.

Which is what I’m saying about geneticists — their tools don’t work (also here) and the Nobel committee fails to notice (e.g., the recent award for teleomere research, which hasn’t yet had practical value).

You have a great phrase in The Black Swan: “Don’t drive a school bus blindfolded.” Is that still happening?
Worse. I was talking about Bernanke – they’ve given him a bigger bus.

Thanks to Dave Lull.

Written With A Straight Face? Dept.

Seth Roberts18 Comments

Jonathan Cole used to be provost of Colombia University. He has written a book called T he Great American University, in which, according to this review,

He lists their dazzling achievements, which in biology and medicine include findings on gene-splicing, recombinant DNA, retroviruses, cancer therapies, coch­lear implants, the fetal ultrasound scanner, the hepatitis B vaccine, prions, stem cells, organ transplantation and even a treatment for head lice. . . . In a chapter on the social sciences, he cites, among many others, such useful innovations as theories of human capital and social mobility, research in linguistics and even the use of prices to reduce traffic jams.

“Research in linguistics”? Yes, that sounds dazzling. I’m sure those “theories of human capital” have been v v “useful”. And who would have thought that if you raise the price of something (“use of prices to reduce traffic jams”) . . . people use less of it? Which was traffic engineering, not social science. Did the reviewer, an economics professor at Harvard named Claudia Goldin, write this with a straight face?

The “dazzling achievements” in biology and medicine are only slightly less unconvincing.”Gene splicing” and “recombinant DNA” research are different names for the same thing. Fetal ultrasound scanners may cause autism. Vaccines were not invented by an American university professor. The discovery of prions has had no obvious non-laboratory use — besides being questionable. Stem-cell research has yet to produce anything of use outside of labs. To be fair, gene splicing has been used to produce human insulin, which is better than the insulin previously available, but conspicuously absent from the list of accomplishments is prevention of diabetes — not to mention allergies, obesity, depression, arthritis, stroke, or any of the other lifestyle problems that a large fraction of Americans suffer from. Such achievements would be truly useful. Great American universities haven’t given us any of those . . but they have given us a treatment for head lice.

There’s a reason for the term ivory tower. Apparently Cole, conscious of the term, is trying to argue against it — but merely shows why it exists. (I’m assuming the review is accurate.) It reminds me of the time that top Chinese students, visiting top American colleges such as Harvard and Yale, found the American students ignorant and arrogant. The theme of Cole’s book is that American universities are in trouble and need more support. What useful stuff they’ve accomplished is central to his argument. When I was an undergrad, I read Thorstein Veblen’s bitter The Higher Learning in America, which said American universities were dysfunctional. He mentioned “committees for the sifting of sawdust.”

More “Graduate school in the humanities is a trap” (via Marginal Revolution).

Visible Big vs. Invisible Small

Seth Roberts2 Comments

In the current New Yorker, James Surowiecki writes:

The bailout of the auto industry, after all, was as unpopular as the bailout of the banks, even though it was much tougher on the companies (G.M. and Chrysler went bankrupt; shareholders were wiped out, and C.E.O.s pushed out), and even though the biggest beneficiaries of the deal were ordinary autoworkers. You might have expected a deal that helped workers keep their jobs to play well in a country spooked by ballooning unemployment. Yet most voters hated it.

Yes, rewarding failure doesn’t play well. The voters were right. The same money that was used to give a few giant companies a second (or third) chance could have been used to give many thousands of very small companies a first chance. It could have been used to help many thousands of people start new small businesses (often one-person businesses) or keep their new small business afloat. All those small businesses would have provided plenty of jobs. and they would have had a far more promising future, far more room for growth, than the Big Three, being both far more diverse and having not already failed. The many thousands of people who wanted to start small businesses were unable to get together and make themselves visible, so the failure of government to help them went unnoticed. Their diversity was economic strength but political weakness.

It’ isn’t surprising things happened as they did — the Big Three (not to mention Wall Street) were bailed out, small businesses were ignored — but it is an indication of how poorly our economy is managed in the most basic ways. I’m not even an economist and I understand this simple point. Bernanke and Summers do not.

It’s easy for me to understand because the same thing happens in science. Government support of research is a good idea, but the money is misspent, in the same way. Grant support goes to a few large projects — generally to people who have already failed (to do anything useful) — rather than to a large number of small projects that haven’t yet failed. The way to support innovation is to place many small bets not a few big ones. That’s one thing I learned from self-experimentation, which allowed me to place many small bets.