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Saturday, May 04, 2013

Forks Over Knives Revisited

I have, in the past, touted the miracle "cure-all" medicine of a mostly plant based diet. The documentary Forks Over Knives struck me as a wonderful example of people giving up traditional pill based sick care for "let food be thy medicine" health care. They were careful not to use the word vegan in the documentary, but "Forks Over Knives" is about being a vegan. I have looked into many dietary ideologies and there are many many paths one can take that are better than the typical American diet. The Forks Over Knives path isn't bad but tough for those who enjoy a little more fat. Another path could be the Atkins Diet approach. Gary Taubes produced a very detailed documentation of the history of cholesterol research in his book "Good Calories Bad Calories". What struck me about the two paths was how they stood in stark contrast to one another yet achieved similar results. There was one common trait however. The lack of sugar and processed foods.

I came upon this critique of Forks Over Knives the other day. It's a blog written by a 26 year old former vegan who now survives on a raw food diet with some meat in the picture. She is also an English major taking on the MDs who started the Forks Over Knives movement. Her name is Denise Minger. She is Davy fighting Goliath.

We all share a common belief in the powers of what we eat. We share an interest in seeing people get healthy by taking aim at their behavior. We also have skepticism built into our DNA. We all like positive results, but here is where we must avoid being Cargo Cult Scientists. What matters is finding the most probable reasons for the outcomes we like so much.

The first thing we at the CCS must address is part of the documentary regarding the Nazi occupation of Norway. The message was that meat rationing led to a rapid reduction in death from cardiovascular disease. What was missing was the fact that the rationing of meat began one year after the reduction of death from cardiovascular disease.

It's a kind of scientific integrity,
a principle of scientific thought that corresponds to a kind of
utter honesty--a kind of leaning over backwards. For example, if
you're doing an experiment, you should report everything that you
think might make it invalid--not only what you think is right about
it: other causes that could possibly explain your results; and
things you thought of that you've eliminated by some other
experiment, and how they worked--to make sure the other fellow can
tell they have been eliminated. - R. Feynman

During the first year [starting in spring of 1940] the rationing included all imported foods, bread, fats, sugar, coffee, cocoa, syrup, and coffee substitute. In the second year [starting in late 1941] all kinds of meat and pork, eggs, milk and dairy products were rationed
The question now is how this information was dealt with by the Forks Over Knives people. Did they, as Feyman  instructs, "report everything that you think might make it invalid".  I think this information might make vegans cringe. What other causes could explain these results? Sugar? bread? syrup? Fats? Luckily for us, Denise Minger got the attention of T Colin Cambell. This response was a testament to her work. Unfortunately in his response he failed to specifically address the actual scientific studies that were of dubious quality, yet made it into the film for dramatic affects. 

I'd like to highlight the condescending response and some of the Cargo Cultisms therein. The response begins with a classic ad Hominem logical fallacy, a veiled attack on Ms. Mingers qualifications to question the Great Oz's of medical science. 
Kudos to Ms. Minger for having the interest, and taking the time, to do considerable 
analysis, and for describing her findings in readily accessible language. And kudos to 
her for being clear and admitting, right up front, that she is neither a statistician nor an 
epidemiologist, but an English major with a love for writing and an interest in nutrition. 
We need more people with this kind of interest.
Silly rabbit, Tricks are for kids... and science is for doctors. The Cargo Cult message here is that they are doctors and she is only an English major. Not even an English PhD! 

Next up in the Cargo Cult Science department is the appeal that no specific part of their Cargo Cult ceremony brings the cargo. It is only the complicated intermingling of this-that-and-the-other-thing that makes the narrative work. It's the George Bush Jr. cop-out. Sure we lied to get the war started but now that Sadam is dead, it all worked out for the best. Dr. Campbell organized his thusly:
My response can be divided into three parts, mostly addressing her lack of  proportionality—what’s important and what’s not.    •Misunderstanding our book’s objectives and my research findings    •Excessive reliance on the use of unadjusted correlations in the China database    •Failure to note the broader implications of choosing the right dietary lifestyle 
Let's slow down the straw man argument for a moment and see if Dr. Campbell addresses the above Nazi/Norway dilemma or the following specific question by Ms. Minger:
What we’re interested in is the sentence near the bottom, which the film’s producers apparently didn’t notice: ”In all, 30 rats on the high-protein diet and 12 on the low-protein diet survived for more than a year.”
To which we get the response:
First and foremost, our extensive work on the biochemical fundamentals of the casein 
effect on experimental cancer in laboratory animals (only partly described in our book) 
was prominent because these findings led to my suggestion of fundamental principles 
and concepts that apply to the broader effects of nutrition on cancer development. 

So... what about the damned rats dying?  What about those sugar-free Norwegian vegans? Dr. Campbell says:

The China research project was a cornerstone study, yes, but it was NOT the sole
determinant of my views (as I have repeated, almost ad nauseum in my lectures). In
doing so, and except for a few denigrating remarks on our experimental animal
, she also ignores the remaining findings that I presented in our book. She
seems not to understand what our laboratory research was showing. Using univariate
correlations mostly without adjustment for confounding factors, qualification of variable
authenticity, and/or biological plausibility can lead to haphazard evidence, subject to the
whims of personal bias. Also, univariate correlations of this type can lead to too memphasis on individual nutrients and foods as potential causes of events.  
Why wasn't their a reference for the denigrating remarks? More importantly, why didn't Dr. Campbnell start advocating a high protein diet for rats hoping to increase their time in the vivarium. Dr. Campbell again wants the reader to keep focused on his narrative and ignore the facts found in his research laboratory. 

The "univariate correlations" conversation is yet another attempt to hide the somewhat dodgy research findings that were used in presenting the Forks Over Knives narrative. The only thing I have to add to this discussion is this. If they aren't significant, why did we hear so much about them? This area right here, where we are suppose to ignore the little studies, yet still believe the narrative they support. really starts to get old. If it doesn't matter, tell us why. Don't bring it up and berate us non-PhD/MDs and English majors for asking you questions. You are suppose to be defending your research, not the insignificance of what you publish. 

I must commend Denise Minger for what she has done. She is Davy fighting the mighty Goliath. I think we can all agree that we care about food as medicine and being healthy. So much passion has Denise for this issue, that she took on a highly popular movement that is in fact a million times better than the diet on which I was raised. I would like to say something nice about Dr. Campbell but I'll end with something he said to Ms. Minger ... which was very Cargo Cult. 

I should conclude by noting the suggestion of the professional epidemiologist, cited  above, who suggested that ultimately Denise may wish to publish her findings in a peer- reviewed journal but who presently felt strongly that the current version would not be  accepted. I concur. 
I have never tired of my own narrative, that most of what gets published is pure bullshit. We all know that science journal editors do not practice the scientific method and thus Ms. Minger does not have the proper credentials to get published. We also know that Dr. Campbell does. What he is suggesting here is that, once again, he is a doctor and she is an English major. You win that one Dr. Campbell. You have surprisingly rejected her paper.
She sure did get Dr. Campbells goat though.
In honor of Ms. Minger, I'm going to sprinkle a little goat cheese on my salad tonight.

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