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Thursday, March 15, 2012

It's Very Difficult to Actually Master a Subject

In my recent diet post, a number of commentators accused me of posting on something I knew nothing about. But that is the very point... I know nothing about nutrition science. But I know I don't know anything about it, so I listen to the experts. Sure they may be wrong, but they are my best bet.

The problem the people commenting have is that they don't know anything about nutrition science either, but they think they do, because they have read a couple of diet books. The people they are challenging, on the other hand, have spent decades researching this stuff full time. Compared to them, the fact that you've read six books on the paleo diet is so close to nothing that calling it nothing is fairly accurate.

And this applies to about any subject, say, canon law. Here is a nice quote from Professor Peters:

"A professional knows the limits of his knowledge. An amateur does not know the limits of his knowledge. A dilettante does not know that there are any limits to his knowledge."

25 comments:

  1. Taubes' post on this anti-meat study points out the standard errors for this kind of study. Apparently it is even worse than normal, since the correlation is so low.
    This, like the climate change stuff, just isn't science. A teenager can understand the limits of epidemiology, computer simulations, overdependence on math in economics, etc... It doesn't require vast knowledge in a particular field, but familiarity with the knowledge that is necessary to properly set up experiments (and allow for their repeatability) in every field.

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    1. "This, like the climate change stuff, just isn't science."

      Ah, you're an expert on climate science too, August! The ten years those pros spent studying it... you understood it all in ninth grade.

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    2. That's my point Gene. There's no need to be an expert in the field when it is obvious they aren't following the scientific method. You can learn about how to run a proper experiment and the need for other people to be able to repeat your experiments in the ninth grade! A teenager can read a study and determine whether or not it is scientific.
      They are doing computer modeling stuff in DNA research too. Run an experiment through the computer model and run the same experiment on actual DNA at the same time. How high does the error rate have to be before you start suggesting maybe we shouldn't draw conclusions based on all those studies that relied on the computer model? How much actual DNA knowledge do you have to have in order to evaluate the error rate?

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    3. "There's no need to be an expert in the field when"

      You can just spout off in the Internet.

      "it is obvious they aren't following the scientific method."

      So, you believe the grammar school nonsense that there is A scientific method!

      "You can learn about how to run a proper experiment and the need for other people to be able to repeat your experiments in the ninth grade!"

      So, your ninth grade understanding of science trumps there decades of experience?!

      Do you realize how well you are making my point?

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    4. I am explicitly saying that the knowledge set required to figure out whether a study is scientific or little more than propaganda is much smaller and much less esoteric than the knowledge set that it takes to become an expert in a field.
      If that makes your point, well I'm happy to share. Keynesians have a knowledge set too, and it is much larger (and more imaginary) than mine, but I still feel justified in my refusal to believe them.

      Interestingly, while commenting on this I realized this would be a good way to teach teenagers critical thinking, and probably the only reason I'd subject myself to plowing through another lousy epidemiological study.

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  2. What is a person who can't identify any limits of the professional's knowledge? A sucker?

    One needn't be a nutrition scientist to see that *Identify the problem->Form hypothesis->Draw conclusions* is hardly a "massive scientific study."

    One would think some of the experts might have attempted to fill in the blanks there. Uh oh.... Or do we just listen to the experts that can get heavy play in popular media?

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    1. 'One needn't be a nutrition scientist to see that *Identify the problem->Form hypothesis->Draw conclusions* is hardly a "massive scientific study.'"

      Mike, this was a study over several decades of over 100,000 people. Your description of it is pure BS.

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  3. Thanks for the link to the canon law blog. I'm always impressed at all the contingencies the Church has already explicitly addressed. It may be made of sinners, but they sure do their homework.

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  4. Yes, I agree with you, Gene. However, you are being disingenuous when you state that you "listen to the experts". The fact is that the science in this subject is highly contested from both sides and both sides do have peer-reviewed studies supporting their positions. The problem is that you're unaware of this fact and that you think that you're listening to the experts by reading a news article about a study. Did you read the study in question? I would bet that you didn't. Well, I did and there are massive holes in it that any non-expert can see.

    The following link lists 25 studies that support the primal and the paleo positions- http://www.robbwolf.com/2011/06/09/us-news-best-diets/studies Trust me, there are a heck of a lot more, I just don't have the time to spend digging them up.

    Also, here is a response to the study that was discussed in the article that you posted. Granted, the person who wrote this response is a "non-expert", but she pretty much talks about the same problems that I saw with it when I read it. The flaws in the study are so blatant that just about anybody can spot them.

    http://www.marksdailyapple.com/will-eating-red-meat-kill-you/#axzz1pENhsqG8

    I'd just like to note that almost all nutritional studies published in nutritional or exercise physiology journals can be found at pubmed.

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    1. Paleo diet ranked dead last amongst 25 diets by panel of experts: http://health.usnews.com/best-diet/best-overall-diets

      And Joseph, do you know "disingenuous" is a fancy word for "liar"? I don't much appreciate that slur!

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    2. Joseph, I very freely acknowledge I amy be dead wrong here. But from what I have seen, the paleo diet is either:

      1) In line with the consensus: eat more vegetables and fruits!

      or

      2) Unfounded: grains and dairy are "poisons"!

      But my whole point is, I have to many other things to research to look into this deeply. So, when Harvard releases a food pie chart, I pretty much figure that's the state of the art at present, and I should eat like that. And when I see DeCoster posting that the Harvard pie-chart recommends lots of sugars (which it doesn't at all!) or processed oils (again it doesn't!) and I don't see lots of other paleos arriving to tell her to stop being so dumb, then I am led to wonder about the entire paleo thing.

      So, yes, maybe YOU have something you are going on, but what I've seen out there looks like nonsense.

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    3. I must admit that my language was a little mean (in a nice way). However, I figured that you were attempting to pull the 'ol 'slippery Kuehn' on me. From my perspective it appeared that you were saying that you listen to the experts, yet everything that you posted was from a news article or from that stupid wiki. Obviously, that doesn't count as listening to the experts.

      As I said, there is no one version of paleo or primal or whatever, just as there is no one version of vegetarianism or low-carb or high carb, etc. Also, I have mentioned before my distaste with DeCoster on some issues. I find her very offensive and oftentimes very wrong. She is, at least regarding diet, a paleo nazi in my opinion. Also, no paleos that I know even frequent her site to tell her that she is "being dumb".

      Now, to give you my perspective on paleo...

      Grains, legumes and dairy are not poisons. The argument is that they contain anti-nutrients (which they unquestionably do) that outweigh their nutritional benefits, and that many people (most) have not fully adapted to those anti-nutrients (lectins, glutens, phytates, lactose, etc), thus causing problems. Also, while paleolithic man most certainly would have eaten anything edible, his intake of these foods would have been quite small compared to vegetation and meats (including organs and bone marrow).

      Paleo/primal also does not take a one size fits all approach. It takes into account that different populations in different regions would have different diets and macronutrient profiles. For instance, if you lived in the tropics, then you probably had far more access to carb energy year round (with lots of fruits), whereas if you lived in northern regions, you only had access to carbs part of the year. Sure, primal/paleo does lay out some guidelines to help, but it also encourages experimentation to find what works for you, the individual.

      In my case, I find that my body responds best to a macronutrient profile of 10-15% carbs, 20-30% proteins and 50-60%. I can eat things like rice and quinoa, but corn, wheat, oat and other more grassy grains make me feel like crap. I can eat dairy with no problems, but I tend to slick to those with low lactose (greek yogurt and aged cheeses). Due to my G6PD deficiency, I cannot eat legumes at all.

      The starting point for most people is to go with Cordain's version of paleo and then reintroduce foods and pay attention to how they affect your body. Some people do well on higher carbs, while others do not. Some can take some grains, others can't eat them at all. However, people usually don't realize these things until they start from a clean slate of veggies and meats with some fruits and nuts/seeds (things humans most certainly have adapted to) and then reintroduce certain foods and pay attention to their body.

      One thing is for certain, the standard American diet that is eaten today is killing us, and if it doesn't kill us then it makes our quality of life complete crap in later years.

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    4. "From my perspective it appeared that you were saying that you listen to the experts, yet everything that you posted was from a news article..."

      Which was describing the view of experts.

      "Grains, legumes and dairy are not poisons. The argument is that they contain anti-nutrients (which they unquestionably do) that outweigh their nutritional benefits..."

      "Antinutrients are found at some level in almost all foods for a variety of reasons. However, their levels are reduced in modern crops, probably as an outcome of the process of domestication." -- Wikipedia on antinutrients

      So all foods have these, but farmed foods have FEWER than wild ones. You have this exactly backwards!

      "One thing is for certain, the standard American diet that is eaten today is killing us..."

      That must be why our life span is so long!

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    5. And Joseph, did you ever notice that my original post never mentioned "paleo" or "primal" diets? It linked to a post by DeCoster. I was criticizing *her* approach to these issues. If there are people out there calling themselves paleo who are more sensible, how does that impact my point at all?

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    6. "Which was describing the view of experts"

      Ok, I'll give you that one. However, once one actually read the study in question you realized that the results were based on questionaires, not a controlled study. Also, there were many other variables, most of which would be almost impossible to completely adjust for. These were concerns that I expressed even before I read the study or critiques of the study emerged. Lo and behold, those were the exact problems with the study. I've read enough of them to know that this is a common occurrence.

      "Wikipedia on anti-nutrients"

      Yes, phytochemicals (of which anti-nutrients are a part) are found in all plants, that is not the argument. The fact is that we have adapted well to some but now others. I explicitly listed the ones that I was talking about. And, yes, there is a ton of peer-reviewed and controlled studies showing that those particular anti-nutrients are troublesome.

      "That must be why our life span is so long"

      Gene, look again at what I said. I was talking about something that most people in the dietetics field would agree on. Not only that, but I was talking about something specific, the SAD, which typically includes many processed foods, sugars, omega 6s, hydrogenated oils, high carbohydrates, etc; does kill many people, and what people it doesn't kill it makes their lives very crappy in later years of life. Heart disease, cancer, diabetes are HUGE problems in this country. Just because medical technology allows you to switch out your old heart for another doesn't mean that it isn't your diet that ultimately gave you the heart disease that kills you 10 years later. How many people simply die of "old age" these days vs those that die of heart disease or other diet related illnesses. Also, of those who die of diet related illnesses, how protracted are those illnesses?

      Further, there is much more that goes into life expectancy than just diet and not every american eats the SAD.

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    7. "If there are people out there calling themselves paleo who are more sensible, how does that impact my point at all?"

      Darnit, Gene. You've got me there.

      However, because she is a paleo eater (albeit, a paleo Nazi) and that she is talking about Tom Woods and Lew (who are more in line with my thinking), I assumed the word "crackpot" was an all-encompassing term for anybody who subscribes to the primal/paleo nutritional category. If that isn't the case, then I apologize.

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    8. No need to apologize -- I could have been more clear.

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    9. BTW, I don't know if you have noticed that your blog is one of the very few sites that I continue to post comments on since my loss of a home internet connection. I wish that I could explain that, but I can't. LOL

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  5. The real irony here is that you're dismissing the opinions of others based on their arrogance in their lack of expertise in nutrition science while you were linking to a RationalWiki article written by someone with no apparent expertise in nutrition science at all. So this is one of your experts who "spent decades researching this stuff full time"?

    That aside, proficiency in the field of nutrition science is not the only angle upon which such a study can be approached. Studies and their data/statistics are a subject unto themselves. It is easy to formulate valid criticisms based on the type of study and the type of error you can expect from the data/statistics in such studies, without being an expert on the study's subject matter at all.

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    1. "The real irony here is that you're dismissing the opinions of others based on their arrogance in their lack of expertise in nutrition science while you were linking to a RationalWiki article written by someone with no apparent expertise in nutrition science at all."

      No, Eric, there is no "irony" here at all: the author of that article REALIZES he has no expertise, and therefore defers to the experts.

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    2. Uh Gene, it's a she, not a he. I would've figured you could at least be bothered to click the link and see for yourself.

      And she (and the person before her) hardly defer to the experts except in a selective manner, which you also would've found out if you had glanced at the Talk page before you started using that article as a defense.

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    3. "Uh Gene, it's a she, not a he. I would've figured you could at least be bothered to click the link and see for yourself."

      Why would I? It's an encyclopedia article, not original research.

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  6. I wouldn't say you're being disingenuous, but I do think you're using your verbal superiority to pick on the instincts of your commentariat a little.

    This may not be the best case to decry experts making a mess of things, but a distrust of expert advice on things that individuals can evaluate for themselves (like diet) is probably not a bad thing, especially considering the authoritarian trends of our society. Your trust in the market to answer questions like this is not crazy, but you don't seem to acknowledge the possibility that it's herd thinking. Did you see Moneyball?

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    1. Gabe, markets make mistakes. Experts make mistakes.

      If I had ten or fifteen years to evaluate diet claims, I might wind up betting against the market.

      But I don't, so I'm betting with it.

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  7. Yeah, me too. Also, the herd mentality is probably even more in evidence in the people pushing the paleo-diet.

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