Category: fallibility of experts

My Dental Exam: Good Gums

Seth Roberts14 Comments

A week ago I had my teeth cleaned. So dirty! said the dental hygienist. This wasn’t surprising. Because I am in China a lot, I get my teeth cleaned only twice per year. Long ago they got dirty so fast my dentist insisted on four cleanings per year. “But aren’t my gums okay?” I asked the hygienist. They felt okay. Not tender. They did’t bleed when I flossed (which wasn’t often). No, she said. You have pockets of 5 (= 5 mm depth). There is bleeding. Indeed, when I washed out my mouth with water at the end, there was some blood.

Yesterday I had my teeth examined. The hygienist was wrong. Almost all my pockets were 2′s, with a few 3s. That’s very good and a vast improvement from the 4s and 5s I had before I became a big fan of flaxseed oil. My gums improved exactly when I started drinking flaxseed oil, no doubt because the omega-3 in flaxseed oil reduces inflammation. My gums were fine in spite of all the plaque — which is supposed to make gums bad. Apparently the hygienist was so devoted to her theory (lots of plaque = bad gums) that she failed to see an exception she stared at for 30 minutes.

There is a well-established correlation between gum disease and heart disease (more gum disease, more heart disease), probably because both are caused by inflammation. So good gums is very good news — it shows I am doing a good job of reducing inflammation throughout my body. These results also support two of my pet theories:

1. Studying what foods make the brain work best is a good way to improve overall health. I started studying flaxseed oil, and how much to take, because I discovered by accident that it improved my balance. Experiments (what is the effect of flaxseed oil on my balance?) soon showed the optimum amount/day was more than flaxseed oil makers recommended! Before I started eating lots of butter, the optimum for me was about 3 tablespoons/day. After I started eating lots of butter, the optimum seems to have gone down to 2 tablespoons/day. Gum improvement seems to be easy to notice at about 1 tablespoon/day.

2. Our health care system fails to get the simplest things right. Omega-3 is not a mysterious nutrient. It has been shown to improve health in thousands of studies. It is well-known that it is anti-inflammatory. It is also well-known that too much inflammation is a major problem. Even so, our health care system has failed to grasp that a large fraction of the population eats too little omega-3 and this has an easy fix. Other examples of failure to get the simplest things right include gastroenterologists not realizing that digestive problems may be caused by food, dermatologists not realizing that acne may be caused by food, and everyone not realizing that cutting off part of the immune system (tonsillectomies) is a terrible idea.

What other simple things does our health care system get wrong?

The Glacially-Slow Conquest of Scurvy And Its Relevance to Modern Life

Seth Roberts9 Comments

Scurvy is a disease of civilization because you need civilization to make long ocean voyages. It is the first disease of civilization to be understood and eliminated. In a paper called “Innovation and Evaluation” (gated), Frederick Mosteller, a professor of statistics at Harvard, noted how long it took. In 1601, James Lancaster, a sea captain, did an experiment involving four ships on a long voyage. Men on one ship got lemon juice, men on the other three ships did not. The men given lemon juice were far less likely to get scurvy. In 1747, James Lind, a doctor, compared six purported cures for scurvy. Lemons and oranges (one cure) were much better than the other five (as Lind expected). In 1795 the British Navy started using citrus juice regularly and wiped out scurvy on their ships. In 1865, the British Board of Trade recommended citrus juice for commercial ships. It took more than 200 years for a simple and effective remedy — discovered before Lancaster — to spread widely.

The sailors at risk of scurvy did not control what they ate. The people who controlled what they ate never got scurvy. Sure, the people who controlled what sailors ate did not want them to get scurvy (high rates of scurvy were a big problem) but they also had other concerns. The lesson I draw from this story is do not let anyone else (doctor, expert, etc.) solve your health problems for you. Sure, other people, as part of their job, will sell you something, provide advice, write a prescription, provide therapy, do surgery, whatever. It might work. They want to help you — the more they help you, the better they look, the more business they attract. But it is entirely possible, this bit of history teaches, that they are slow on the uptake or have conflicts of interest and a much better solution is available.

Thanks to Steve Hansen.

Assorted Links

Seth Roberts6 Comments
  • In praise of Rush Limbaugh.
  • Shangri-La Diet experience (“Bottom line: I lost three pounds in a week and a half”) of an artist named Elizabeth Periale.
  • Long interview with Tucker Max. “His fridge . . . is in one way very different: where you’d expect the six-pack of cold ones waiting for the game, instead you’ll find rows and rows of kombucha, the fermented health beverage.”
  • End of college campuses. Megan McArdle imagines a world in which college is replaced by distance learning. “95% of tenure-track jobs will be eliminated.” Jane Jacobs, in Systems of Survival, divided jobs into taking and trading. Teaching is trading if the student really wants to learn the subject. Teaching is taking if the student is forced to take (and pay for) the class. Scary thought: Every college student is asked about every class: would you take this class if you didn’t need to (and didn’t need to take other classes)?

“Thou Shalt Not Testify Against Another Doctor”

Seth Roberts2 Comments

First do no harm . . . As Robin Hanson has said, what does that mean? In contrast, the rule illustrated by this story, from Bryan Castañeda, who works for a Los Angeles law firm, is quite clear:

At the old firm I used to work at, I was talking to one of the senior attorneys and the topic of medical malpractice cases came up. He said he avoids them. Why, I asked. He said — I’m paraphrasing here — “Because you won’t find a doctor who will testify against another doctor in open court. They may advise you in private, ‘Oh yeah, so-and-so definitely screwed up,’ but you won’t get them to say that on the stand. They all protect each other.”

Judging by this story, if your doctor makes a mistake, the only person who will suffer consequences is you. Thank heavens the rest of us have more power than ever before. A recent survey of doctors found that “more than a 10th (11.3%) admitted to telling patients something that was not true.” The survey did not ask about lies of omission (when silence is misleading); unwillingness to testify that someone else made a mistake is that sort of lie. The survey also showed that doctors (at least, those who took the survey) have a self-serving interpretation of the term not true. Although only about 10% said they had said something “that was not true” — meaning something that they knew wasn’t true — “more than half had described a patient’s prognosis more optimistically than warranted.” Apparently they consider such descriptions not instances of “not true”.

In Systems of Survival, Jane Jacobs described two moral systems (lists of rules/values): The guardian syndrome and the commercial syndrome. In certain areas of life (e.g., military), the guardian syndrome prevailed; in other areas (e.g., small business), the commercial syndrome prevailed. Loyalty (e.g., “never testify against a fellow doctor”) is a guardian value — indeed, the main guardian value. In contrast, honesty is the main commercial value. Jacobs said that the two syndromes corresponded to two ways of making a living: taking and trading. Doctors do not represent themselves as predatory (= taking). But, according to Jacobs, this sort of rule (“never testify against a fellow doctor”) puts them squarely in that camp.

I asked Jim Jacobs, one of Jane Jacobs’s sons, for comment. He replied:

Exactly right. Jane experienced this herself, unfortunately. It’s really a major problem. I see the very same behavior among medical researchers too.

Excellent Customer Service From Fidelity Investments

Seth Roberts6 Comments

Because I am in China, I want my new credit card sent here. After 45 minutes arranging this, my credit-card company asked me one last security question: What were the last four digits of the bank account used to pay my most recent bill? I told them. They said my answer was wrong. Huh?

I pay my credit card bills through Fidelity Investments (which is not a bank). I contacted them. I was routed to their BillPay department. The person who helped me, whose name I wish I had written down, said that he was as puzzled as I was. It was not clear at all why my answer was wrong. He suggested a conference call. He started a conference call with my credit-card company. Within a few minutes, he and the credit-card company representative figured out that there was a mistake in the number listed by the credit-card company. Their software had lost the last digit of my account number, so that if my account number had ended in 12345, their records would have showed 1234. (Yet the payment still went through.)

I was greatly relieved. “At least the problem had a solution!” I told the credit-card-company representative. Imagine not being able to control one’s money because of a software error. I was/am grateful to the Fidelity representative for quickly solving a problem that had nothing to do with Fidelity.

You might think that such heavily-used software would by now be free of bugs. But it wasn’t.