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The China Study Revisited: New Analysis of Raw Data Doesn’t Support Vegetarian Ideology

Over a year ago I wrote about The China Study, a book by T. Colin Campbell and his son based on a huge epidemiologic study of diet and health done in China. The book’s major thesis is that we could prevent or cure most disease (heart disease, cancer, diabetes, autoimmune diseases, bone, kidney, eye and other diseases) by eating a whole foods plant-based diet, drastically reducing our protein intake, and avoiding meat and dairy products entirely.

I noticed a number of things in the book that bothered me. I found evidence of sloppy citations, cherry-picked references, omission of data that contradicted the thesis, and recommendations that went beyond the data. I concluded:

He marshals a lot of evidence, but is it sufficient to support his recommendation that everyone give up animal protein entirely, including dairy products? I don’t think so.

The China Study involved 367 variables and 8000 correlations. I said I would leave it to others to comment on the study design and the statistical analysis, and now someone has done just that.  Denise Minger devoted a month and a half to examining the raw data to see how closely Campbell’s claims aligned with the data he drew from; she found many weaknesses and errors.

Campbell says

Plasma cholesterol… is positively associated with most cancer mortality rates. Plasma cholesterol is positively associated with animal protein intake and inversely associated with plant protein intake.

The data do show that cholesterol is positively associated with various cancers, that cholesterol is positively associated with animal protein, and that cholesterol is negatively associated with plant protein. So by indirect deduction they assume that animal protein is associated with cancers and that reducing intake is protective. But if you compare animal protein intake directly with cancer, there are as many negative correlations as positive, and not one of those correlations reaches a level of statistical significance. Comparing dietary plant protein to various types of cancer, there are many more positive correlations and one of them does show strong statistical significance. The variable “death from all cancers” is four times as strongly associated with plant protein as with animal protein. And Campbell fails to mention an important confounder: cholesterol is higher in geographic areas with a higher incidence of schistosomiasis and hepatitis B infection, both risk factors for cancer.

Campbell says breast cancer is associated with dietary fat (which is associated with animal protein intake). The data show a non-significant association with dietary fat, but stronger (still non-significant) associations with several other factors and a significant association with wine, alcohol, and blood glucose level. The (non-significant) association of breast cancer with legume intake is virtually identical to the (non-significant) association with dietary fat. Animal protein itself shows a weaker correlation with breast cancer than light-colored vegetables, legume intake, fruit, and a number of other purportedly healthy plant foods.)

He indicts animal protein as being correlated with cardiovascular disease, but fails to mention that plant protein is more strongly correlated and wheat protein is far, far more strongly correlated. The China Study data show the opposite of what Campbell claims: animal protein doesn’t correspond with more disease, even in the highest animal food-eating counties.

These are just a couple of examples. Minger found many more, which she describes in her long article, complete with impressive graphs. Her exposé is well worth reading in its entirety, if only as a demonstration of how to think about epidemiologic data.

Minger goes on to reveal gaping logical holes in Campbell’s own research on casein, a milk protein that he believes causes cancer. He showed that casein was associated with cancer when given in isolation to lab animals, but he projects those results onto humans and onto all sources of animal protein. Other animal proteins have been shown to have anti-cancer effects, and the results of a normal diet containing multiple protein sources are likely to be very different from his casein-only studies.

Minger concludes

 I believe Campbell was influenced by his own expectations about animal protein and disease, leading him to seek out specific correlations in the China Study data (and elsewhere) to confirm his predictions.

She is being polite.

This is a cautionary tale. It shows how complex issues can be over-simplified into meaninglessness, how epidemiologic data can be misinterpreted and mislead us, and how a researcher can approach a problem with preconceptions that allow him to see only what he wants to see. The China Study was embraced by vegetarians because it seemed to support their beliefs with strong evidence. Minger has shown that that evidence is largely illusory. The issues raised are important and deserve further study by unbiased scientists. At any rate, one thing is clear: the China Study is not sufficient reason to recommend drastic reductions in protein intake, let alone total avoidance of meat and dairy foods.

Posted in: Cancer, Nutrition

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58 thoughts on “The China Study Revisited: New Analysis of Raw Data Doesn’t Support Vegetarian Ideology

  1. It is frustrating to me when people who advocate a position I agree with do so for terrible reasons. As far as I’m aware, there are no major health advantages (or disadvantages!) to being a vegetarian as opposed to an omnivore – there are good and bad omni and vegetarian (and vegan) diets, as far as health is concerned.

    “the China Study is not sufficient reason to recommend drastic reductions in protein intake, let alone total avoidance of meat and dairy foods.”

    Sure. However, preventing a few thousand animals from living miserable lives for no good reason (“I like it” isn’t good enough IMO. And I did like it), and making a significant dent in the energy intensity of my lifestyle – those are pretty good reasons.

    On a vaguely related note, I was disappointed to see one of my favorite vego food companies supporting autism woo on their site. *sigh*

  2. rmgw says:

    This underscores, yet again, the fact that changing to a vegan way of life (not only in one’s diet), is an ethical decision: animal husbandry may or may not be bad for the planet and/or the human body in lots of ways, but the individual decision to end the exploitation of other species in one’s own life is undertaken for purely moral reasons: i.e. that one’s own interests should not automatically trump the interests of others simply because one is in a position to so behave.

  3. Anarres says:

    According the plant neurobiology, plants are both cognitive and sensitive beings, don´t eat them please.

    http://www.plantbehavior.org/
    http://www.dowebsites.net/linv/linv_about.php

    “Concluding, we hope that we have shown here that, in a number of specific issues relating to cognition, animals and plants do not differ fundamentally, and that plants are cognitive in a minimal, embodied sense that also applies to many animals and even bacteria. ”

    Plant-Environment Interactions, p263

    Only joking ;)

  4. eagle747 says:

    I could smell the bad research on the book the moment I heard about it.

  5. I am now astonished by the credulity with which I swallowed and regurgitated vegetarian ideology in the early 90s. I breezily claimed to be a vegetarian for “all the reasons”: environmental, ethical, health, and even spiritual. All of these ideas were unexamined. They sounded good. I think I was basically just boosting the credibility of my lifestyle choice by just naming every benefit I could think of. The only criterion for inclusion in my list of reasons was “does it sound vaguely plausible?”

    I was veggie until about 2005, and then slowly switched to being a “meat minimalist” as I realized how little I really knew about … well, anything. This new analysis of the Chinese data reinforces only one thing: that it’s daft to ardently defend any diet as “healthier.” It cannot yet be done!

  6. DevoutCatalyst says:

    I hate the word “vegan”, but I am one, and this was supposed to produce glorious results forever, but for every now broken promise it is clear there was and is no basis.

    As for ethics, I don’t own pets, but do enjoy leather. A cow is a vegetable, right?

  7. Scott says:

    This new analysis of the Chinese data reinforces only one thing: that it’s daft to ardently defend any diet as “healthier.” It cannot yet be done!

    Well, in some cases it can. A typical Mediterranean diet is readily shown to be healthier than one comprised exclusively of ice cream, granulated sugar, and whiskey. But barring extreme cases like that, I can’t argue with you.

  8. LovleAnjel says:

    “A cow is a vegetable, right?”

    Well, if ketchup is a vegetable, then so is bacon.

  9. bruce9432 says:

    Weren’t vegans studied for like a hundred years and the study included thousands of subjects and it was found there was no difference in health… yeah, I remember, they’re called Seventh-day Adventists.

  10. Robin says:

    >As far as I’m aware, there are no major health advantages (or disadvantages!) to being a vegetarian

    There is some evidence that certain types of vegetarian diets are helpful for cardio-vascular health. But it’s unclear if the effect is from the absence of meat or the abundance of vegetables and beans.

    (Remember, you can eat sheet cake and moutain dew and call yourself a vegetarian, or, eat meatless meals 6 days a week and a small cut of chicken on the seventh and be a meat eater.)

    Anecdotally (don’t shoot me!) a whole foods types vegetarian diet has helped control my cholesterol and avoid taking statins.

  11. Chris says:

    bruce0432, a quick google on the Seventh Day Adventists reveals that they are lacto-ovo vegetarians. Since they eat eggs and consume dairy products they are not vegan.

  12. Ken Hamer says:

    Can I get in on the act?

    - I like vegetarian food… cows are vegetarians aren’t they?
    - Vegetables are what food eats.
    - I think I can make a compelling case (well, to some people) that the fatigue associated with various cancers causes people to need/crave high energy proteins. Therefore, cancer causes meat eating.

  13. SloFox says:

    @ Scott

    Actually a Mediterranean diet has never been compared head-to-head with diet you proposed. The jury’s still out on that one. I’m hoping common sense gets overturned in that battle.

    Mike

  14. Werdna says:

    That’s an interesting post Harriet I’ve been skeptical of Colin Campbell’s work for a while now. I admit I was at first cautious of Denise Minger’s site because she’s essentially doing an analysis but doesn’t appear to have any formal training in statistics and is also something of a raw foods enthusiast. That said what she has attempted is actually a bit cleverer and a whole lot simpler than re-analyzing the China Project data. She’s simply analyzing CC’s conclusions – in light of the China Project data. She also has fact checked, to some degree CC’s hand-waving argument that you can’t just look at raw values. Demonstrating that it appears he did just that in many cases.

    Anyway so far, outside of a few quibbles with some technical things like the definition of a P-value I’m pretty impressed with her work.

    For those who care saying “p<0.05 (5 in 100 chance that the correlation is accidental)" is not technically correct to a hard–ass like myself but it's such a common misunderstanding and there appears in this case little harm in letting it persist.

  15. Scott – “A typical Mediterranean diet is readily shown to be healthier than one comprised exclusively of ice cream, granulated sugar, and whiskey.”

    Yum, Whiskey Smoothies! You may not live long, but you’ll be able to sing the brain freeze blues with that attractive Tom Waits growl.

  16. oliverboliverbutt says:

    @Chris: Being married to someone who was raised Seventh Day Adventist, I can attest to the fact that there are several subgroups. My in-laws happen to belong to the militant fundamentalist group that are strict vegans and avoid things like spices and salts as well as public schools, mainstream music, and, in general, rational thought. There are the so-called meat-eating milk-drinking SDA’s, but they are looked down upon by their more conservative brethren. You can google Ellen White, who is the SDA prophet and preached a “health” message that has been spun to such an extent that you’ll get one hundred different interpretations, each of whose proponents claim to be the one truth.

  17. BillyJoe says:

    Anarres

    “Only joking ;)

    Good.
    But over at Steven Novella’s Neurologica Blog, there are a couple of indivivduals who take this seriously.
    In fact, even bacteria – hey, even electrons – are conscious!

  18. Anarres says:

    “…even electrons – are conscious!” LOL

    Thank you, I did not know the Novella´s Blog, it’s very interesting.

    BTW we can eat photons :)

    (warning, stupidity inside)

    http://www.consumerhealth.org/articles/display.cfm?ID=19990303162757

  19. TsuDhoNimh says:

    @Chris and @Bruce

    It’s not just the vegan/vegetarian diet. Seventh Day Adventists also avoid smoking and alcohol, which are known lifestyle risk factors.

  20. TsuDhoNimh,

    … which is why Mormons are often used as a control group when studying the SDA diet. Mormons also avoid smoking and alcohol.

  21. Dash says:

    I find the very concept of trying to label a vegetarian or omnivorous diet healthy or unhealthy to be weird, dare I say irrational. How can you possibly decide how healthy a diet is based on the presence or absence (not even looking at amounts) of one ingredient? Does anyone try to argue that diets with or without rice are healthier?

    Anyone who tries to argue an absolute based on one unmeasured but continuous variable in a complex system is far into the realms of pseudo-science.

  22. DevoutCatalyst says:

    “It’s not just the vegan/vegetarian diet. Seventh Day Adventists also avoid smoking and alcohol, which are known lifestyle risk factors.”

    I avoid Seventh Day Adventists, works for me.

  23. MissMarnie says:

    @Dash

    Does anyone try to argue that diets with or without rice are healthier?

    In fact, some do. I have had someone tell me that not only should one eat a primarily vegan raw diet (with many smoothies) but that legumes and grains like rice and wheat are what cause aging and death. She has read and believes that the more work your body has to do to digest food the faster it ages. She learned this from a book written by a homeopath. She doesn’t understand why I consider that reason enough to disbelieve the entire theory.

  24. Chris says:

    And knowing I’d be called out on what I wrote is why I used a Seventh Day Adventist website for the information. Personally, I don’t really care. I just knew they weren’t all vegan.

    Now when was the world supposed to end again?

  25. tmac57 says:

    @Annares :”BTW we can eat photons” I think I sprained my brain reading that site! I do like a good ‘light’ yogurt though ;-)

  26. Calli Arcale says:

    re: eating photons:

    I keep waiting for a con artist to start claiming one can subsist entirely on neutrinos. :-D

  27. Hank Roberts says:

    Any chance of involving a statistician or medical librarian in this thread?

    If there’s a real issue to raise — since all the original data is available online to download — our sciencebasedmedicine’ hosts could bring on someone with the ability to look at the original material, talk with the blogger critiquing it, and write it up for publication.

    That would be a real contribution to the science.

    Since I came across this question I’ve tried posting a comment about it at several of the blogs that have had a lot of praise for the China Study book. So far none of them have appeared. I hope the bloggers are doing a serious look at the statistics in question — or asking someone knowledgable about statistics to do it.

    It’s certainly possible to jump to wrong conclusions using Excel for an amateur. I can’t judge the claims made either by the China Study author or by the blogger criticizing the book.

    Someone should, who can competently comment.
    Hosts, please, invite someone to look in?

  28. @Werdna

    “For those who care saying “p<0.05 (5 in 100 chance that the correlation is accidental)" is not technically correct to a hard–ass like myself but it's such a common misunderstanding and there appears in this case little harm in letting it persist."

    It's worse than that: p = 0.05 is usually roughly equivelent to posterior probability of 0.5 – i.e. as likely as not that the effect is accidental. See for example,

    Testing a point null hypothesis: the irreconcilability of P values and evidence. JO Berger, T Sellke – Journal of the American Statistical Association, 1987

  29. Rob Tarzwell says:

    Interested readers interested in a full and fair weighing of the data may be interested in looking at Colin Campbell’s reply to Minger. He points out a number of very reasonable criticisms of her analysis and actually sounds pretty level-headed to me.

    Dr. Hall, would it be reasonable to ask you to include the link in the main post?

    http://www.vegsource.com/news/2010/07/china-study-author-colin-campbell-slaps-down-critic-denise-minger.html

  30. passionlessDrone says:

    Hi Rob Tarzwell –

    Thank you for posting this link.

    Denise Minger devoted a month and a half to examining the raw data to see how closely Campbell’s claims aligned with the data he drew from.

    In the meantime, Campbell was continuously funded for twenty seven years by the NIH. If only they’d bothered to spend a month looking at the data, imagine what they might have learned. What a joke.

    - pD

  31. Jenna says:

    @Rob Tarzwell – Minger addressed Campbell’s rebuttal with a follow up post:

    http://rawfoodsos.com/2010/07/16/the-china-study-my-response-to-campbell/

    On her blog it says she is also working on a third response to him.

  32. Rob Tarzwell says:

    Thanks for that, Jenna. It will be interesting to see how this tennis match unfolds. Call me conservative, but my money’s on the career academic whose publications withstood peer review over three decades. If Minger really believes she’s on to something, she might want to consider submitting a review article to a nutrition journal.

  33. brett99 says:

    I like Harriette Hall, but I’ve found that her views on diet not particularly well-informed. I’m not sure if she has an ax to grind – I kind of get that impression. She accepts Denise Minger’s work – sad to say – unskeptically. T. Collin Campbell’s work is a collaborative effort that has been through (and survived) extensive peer review for over 20 years. Minger’s work appears to be just her own blogging while she works on her English degree. Hall’s uncritical acceptance of Minger’s work diminishes her credibility, in my eyes.

    Denise Minger doesn’t have the training, experience, or credibility, in my view, to topple the likes of T. Colin Campbell with her rather sarcastic analysis and response. She is a lay person who is intelligent and interested in statistics and diet. Nothing wrong with that, but she is not a relative expert in either field. Her understanding of human biology and digestion (based on other blog entries) is rudimentary. Her own dietary recommendations are in line with the folks at the Westin A. Price foundation (who have their own questionable ideology and agenda – check out their website). That of course doesn’t mean that her views on Campbell’s methodology are therefore wrong, but it does put a bit of a foul smell in the air. Is she really going where the evidence takes her, and is she trained, experienced and unbiased enough to perform this sort of analysis? I’m skeptical of that, and her blog certainly doesn’t make much of a case for this (it is, however, just a blog, and she has every right to her opinions). I was dismayed to read her embarassing dismissal of the academic work of previous generations. She appears to think that young people like herself, working in their apartments, simply because they have access to the Internet, can do as scholarly a job as lifelong academics and scientists were able to do 30 years ago. Please!

    Here is Colin Campbell’s response:

    http://www.vegsource.com/news/2010/07/china-study-author-colin-campbell-slaps-down-critic-denise-minger.html
    or in PDF version, http://www.tcolincampbell.org/fileadmin/Presentation/finalmingercritique.pdf

    I found his rebuttal effective. To his credit, Campbell was also respectful and didn’t resort to routine ad hominems, which (again, sad to say) I picked up from both Hall and Minger towards Campbell. Campbell comes across as a serious academic, while Minger comes across as, frankly, a college student. Sorry about the ad hominem!

    The claims of vegetarians (or skeptics, or anybody for that matter) can be assessed using a standard baloney detection kit (http://www.michaelshermer.com/2009/06/baloney-detection-kit/).

    To sum up what I think about the current state of evidence about the advantages of a vegetarian diet:

    1) Medical Reasons (i.e. a vegetarian diet is healthier for you): the evidence is compelling, but some of the claims of rabid vegetarians are overzealous and unproven (e.g. a vegetarian diet will cure metastatic cancer – this is absolutely unproven and almost certainly untrue – see critiques of the “Gerson Method”). I think the evidence about the positive effects on reversal of heart disease and reduction of rates of some cancers remains strong. I’m ready to change my mind based on new evidence, but I haven’t seen it (Minger and Hall have not produced any new evidence) and am skeptical that the existing evidence is going to be debunked to the point that we need to question most of our previous conclusions. I also think you can eat (in moderation) meat and be perfectly healthy.
    2) Environmental Reasons: the evidence is extremely compelling. So compelling that, for me, the case is closed. A vegetarian diet is better for the environment, period. Don’t believe me – study it for yourself. It is not rocket science.
    3) Animal Welfare reasons: I have an open mind, but I’ve never read any credible rationalization that eating animals is better for the animals themselves or for reducing animal suffering. Peter Singer’s work in this area is, I think, the most compelling.

    1. Harriet Hall says:

      brett99,
      Did you see Campbell’s inadequate response to my previous article? In the comments at http://www.sciencebasedmedicine.org/?p=385 His answer to Minger that you cite follows an earlier answer that was roundly criticized as full of condescending ad hominems and lacking in actual rebuttals of her arguments. I’m not impressed by his new response: instead of focusing on Minger’s points, parts of it are attempts to change the subject, shifting the argument to broader concerns. Your defense of Campbell’s thesis is not substantive: you are fixated on “He’s a respected researcher and she’s not competent” instead of the content of the arguments.
      And I’m puzzled by your statement that my ideas on diet are not well informed, since your own ideas as expressed in point 1) correspond exactly to my own ideas. Incidentally, 2) and 3) are irrelevant to the question of health benefits for humans.

  34. Harriet Hall on vegetarian ideology: “Incidentally, 2) and 3) are irrelevant to the question of health benefits for humans.”

    No they aren’t. (See below.) And even if they were, they are profoundly relevant to vegetarian ideology, which is what your headline refers to.

    2) Ecology: Humans derive health benefits from having enough to eat enough and a clean place to live. Americans who eat beef fed on Mexican corn have a health impact on Mexicans who can’t afford to buy corn. (In my world, Mexicans are human too.) If resources were unlimited, the rich could squander them without affecting the poor. Resources are not unlimited, so the squandering of resources by anyone affects us all. The stress of constantly living with the cognitive dissonance from knowingly making choices that may negatively impact far-away people today, and will definitely negatively impact the next generation, is probably not good for us either.

    3) Animal welfare: When the animals we eat are raised in overcrowded conditions and fed on substances to which they are not adapted, they need daily prophylaxis with antibiotics to keep them alive. This is a source of antibiotic resistance that has strong impacts on human health.

  35. Harriet Hall on ad hominems: “Your defense of Campbell’s thesis is not substantive: you are fixated on “He’s a respected researcher and she’s not competent” instead of the content of the arguments.”

    Ok, so does that mean that the scientists here are going to stop complaining that the general public doesn’t understand that you can’t become a scientist by googling? And are we going to stop hearing that Jenny McCarthy is not competent?

    Fine, Brett99 should be able to restate a compelling argument in their own words, and hasn’t. No points for Brett99 there. Fair enough. But why is “____ is not actually a scientist who knows what they’re doing” relevant when ____ is an anti-vaccinationist but not relevant when ____ is an anti-vegetarian?

  36. brett99 says:

    Thanks for your response, Harriet. I agree with you that my defense of Campbell’s thesis is not substantive. To be fair, though, a substantive defense is not what I set out to do – I’m just putting in a response to your posting as sincerely as possible, like everybody else. Substantive defenses to someone’s life work take a lot of time and space and I wouldn’t choose this forum for doing so. You are also correct in summarizing (minus the “fixation” part) my main point, that Campbell is a respected researcher with a large body of published, peer-reviewed work, and Denise is not. So I am very skeptical of her assertions, as articulated, and was surprised to see that you would accept her blogging efforts as good evidence of sloppy scholarship and disingenuous motives on the part of Campbell. I am used to you being more skeptical than that, and that’s why I wondered if you have an ax to grind. In your posting, you summed up by saying:

    “This is a cautionary tale. It shows how complex issues can be over-simplified into meaninglessness, how epidemiologic data can be misinterpreted and mislead us, and how a researcher can approach a problem with preconceptions that allow him to see only what he wants to see.”

    Huh? Are you really saying that you (and Denise) have proven that Campbell has misinterpreted data and misled the public, and was only out to confirm his preconceived notions? That is quite a claim, and certainly one I don’t think you have successfully substantiated.

    Regarding the summary of the advantages of a vegetarian diet, I do agree with you that point #3 (animal welfare reasons) is not directly relevant to human health issues. However, if you don’t think #2 (environmental reasons) is relevant to human health, I can only surmise that you haven’t really looked deeply at this issue. I really encourage you to do so, as it is quite shocking and has large implications for future generations.

    If Campbell engaged in previous ad hominens towards you or Denise, bad on him for that. I did read his response to your earlier posting, and I think both of you were generally quite respectful, but he was more so. I don’t think that his saying “I am sorry to say, also, that Dr. Hall herself very likely has had no formal training in nutrition” amounts to much of an ad hominem. I think it reflects what he actually thinks, and he stated it as respectfully as possible. I certainly don’t wish to insult you when I say that I don’t think that your views on diet are particularly well-informed. I have enormous respect for you and the work you continue to do. However, that is what I think, based on what I’ve read in your postings, and in particular in your (forgive me, I’m just being honest) presumptive dismissal of T. Colin Campbell’s work. This is, to me, a minor criticism and I am venturing it only because holding each other’s feet to the fire is an excellent way to keep our skeptical skills (which you have in abundance) finely tuned. I’m glad we agree on almost everything else. Thanks again for your response.

    1. Harriet Hall says:

      Umm.. what kind of axe am I supposed to be grinding? Perhaps the axe of moderation and not jumping to conclusions from insufficient data?
      I was inclined to accept Denise’s evidence of sloppy scholarship and disingenuous motives on the part of Campbell because it coincided with my own findings in my original post, http://www.sciencebasedmedicine.org/?p=385, which you did not comment on. If nothing else, Campbell is guilty of going beyond the data in his recommendation to avoid all animal and dairy foods and drastically reduce protein intake. I don’t think I was presumptively dismissing Campbell’s work. In fact, my original post concluded, “The China Study makes a good case, but the case isn’t quite good enough.”
      While environmental issues are pertinent to human health in general and in the future, my focus was on the same thing Campbell’s focus was on: what diet is the healthiest for an individual right now.

  37. Calli Arcale says:

    Allison Cummins:

    3) Animal welfare: When the animals we eat are raised in overcrowded conditions and fed on substances to which they are not adapted, they need daily prophylaxis with antibiotics to keep them alive. This is a source of antibiotic resistance that has strong impacts on human health.

    As I understand it (I’m not in the field), daily antibiotic prophylaxis is not actually required for feedlots and battery hens and similar living conditions. It is widely used, on the *belief* that it makes a difference, but there is no clear evidence it actually does. (Now, it definitely makes a difference whether or not you treat sick animals, but we’re talking about treating the healthy ones.) Indeed, plenty of dairy farms and egg farms and feedlots are proving right now that you can be commercially viable with a large population without using antibiotic prophylaxis.

    We should reduce (and preferably, eliminate) the use of antibiotic prophylaxis, except in particularly vulnerable populations or in the case of trying to contain an outbreak. But it doesn’t follow that we also must eliminate feedlots and such in order to improve human health. More low-tech disease control works fine, even for high-density animal populations. Possibly *especially* for the high-density populations, as there is the opportunity to quarantine the entire group.

  38. brett99 says:

    Thanks again! What I was hoping you would respond to was your statement:

    “This is a cautionary tale. It shows how complex issues can be over-simplified into meaninglessness, how epidemiologic data can be misinterpreted and mislead us, and how a researcher can approach a problem with preconceptions that allow him to see only what he wants to see.”

    I really don’t think you’ve proved this, and I continue to find it presumptive. You saying in your last response that “If nothing else, Campbell is guilty of going beyond the data in his recommendation to avoid all animal and dairy foods and drastically reduce protein intake” is a much more moderate claim which may be at least partly true.

    I did not comment on the content of your original post for time considerations. I thought it was more more moderate than this last one, and your point about Campbell making “problematic references” was a good point (especially the reference to the Gerson study) though I’m not sure that you proved that there was a pattern in Campbell’s referencing.

    However, your quote (in the second paragraph above) represents a much harsher judgement of his work, and accepting Denise’s questionable conclusions (my criticism of her scholarship stands, and you haven’t said anything that would make me think otherwise) as sufficient support to warrant this, again, strikes me as presumptive rather than moderate. Once again, thanks for your responses – I’ve very much enjoyed the conversation.

  39. Calli Arcale on feedlot bloat and antibiotics: “[D]aily antibiotic prophylaxis … is widely used, on the *belief* that it makes a difference, but there is no clear evidence it actually does.”

    E. E. Bartley, T. G. Nagaraja, E. S. Pressman, A. D. Dayton, M. P. Katz and L. R. Fina on antibiotic prophylaxis and feedlot bloat:
    http://jas.fass.org/cgi/content/abstract/56/6/1400

    “Lasalocid at .66 mg/kg effectively prevented bloat from developing when given to animals before the feeding of high grain diets; however, a 1.32-mg dose was required to control bloat in cattle that were already bloating before they were given lasalocid.”

    Alberta Feedlot Management Guide 2nd Edition
    on management of feedlot bloat:
    http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/beef11732

    “Feedlot bloat can be prevented by controlling the particle size of the grain in the ration. If the grain is ground too fine, the rumen bacteria have a readily available surface for digestion and rapid proliferation. A coarse particle size reduces the surface available to the rumen microorganisms, thus it slows the digestion process. As well, feed intake is greater and more constant. Hironaka et al. (2) found that fine particle size feed (388ì) caused foamy rumen contents compared to a coarse particle size feed (715ì) when fed to cows.

    Feed additives, such as monensin or lasalocid (5) may reduce the incidence of bloat in cattle on high grain rations. Adding 4 percent salt, (NaCl) (6) to the diet may control bloat by increasing water intake and diluting the rumen contents. However, this is not a long-term solution; salt also reduces feed intake.”

    wikipedia.org on Monensin:
    http://en.wikipedia.org/wiki/Monensin

    “Monensin, isolated from Streptomyces cinnamonensis, is a well-known representative of naturally polyether ionophore antibiotics. … Monensin is used extensively in the beef and dairy industries to prevent coccidiosis, increase the production of propionic acid and prevent bloat.”

    wikipedia.org on Lasalocid:
    http://en.wikipedia.org/wiki/Lasalocid

    “Lasalocid is an antibacterial agent and a coccidiostat. It is the drug in the feed additive called Bovatec.”

    It sounds as though there’s evidence that it does make a difference, but perhaps no evidence that it’s necessary with careful feed management. It also sounds as though that it may at times be easier and cheaper to feed grain and prophylactic Lasalocid than to delay weight gain by restricting feed and feeding hay. Since easy and cheap are what the beef market is driven by, that’s what we get.

    My question now is… does resistance to Monensin and Lasalocid have any clinical application to humans? Are these drugs related to drugs that we take in a way that cross-resistance would be clinically relevant?

  40. JonM says:

    Hi brett99,

    I do not really understand why people are making an issue of Minger’s age and experience. She just pointed out some rather obvious flaws in Campbell’s paper; she did not do any science of her own. Any college student writing a term paper could have accomplished something similar, though Minger is particularly talented at getting to the heart of issues and untangling these issues in a very logical and readable manner.

    Campbell has repeatedly used casein to vilify all animal protein, as in the quote below from the article
    “Are All Proteins Created Equal?” found at the Campbell Coalition website (http://www.campbellcoalition.org/?p=127)

    “casein is the most relevant chemical carcinogen we ever tested, with a high probability that all animal-based proteins would do the same thing, similar to their behavior with other responses.”

    Minger just showed how poor this argument is, especially when used to indict all animal protein:
    1) The statement is factually false because similar studies have been performed with whey protein, another animal protein, which showed anti-cancer properties. Therefore no “high-probability” of similar results.
    2) Campbell’s rat study showed that when casein combined with aflatoxin and sucrose was compared to a plant protein under the same conditions, cancer in cancer-prone rats spread more quickly. It does not mean that the casein caused the cancer.
    3) Casein is a complete protein while the plant protein was incomplete. When the missing amino acid was added, plant protein exhibited a stronger effect in line with casein.
    4) The casein used was in an isolated state which does not often occur naturally. It is often combined with whey (which has anti-cancer properties) in natural dairy products.

    You don’t have to be a great scientist to see that Campbell’s statement is false (and some would argue a blatant lie). Casein is no more relevant a carcinogen than lysine-fortified wheat, and similar studies with whey show that there is actually ZERO “probability that all animal-based proteins would do the same thing.” Yet Campbell keeps using this argument over and over again to indict all animal protein.

    As far as the statistics are concerned, Minger just pointed out some issues with Cambpell cherry-picking certain univariate correlations to bolster his case. She showed that he ignored contradictory correlations, ignored confounding factors, used questionable surrogates for animal protein consumption, and in certain cases such as CVD and cholesterol ignored his own peer-reviewed studies where multivariate analysis showed no correlation.

    The most telling aspect in all this is Campbell’s response. He basically has said as long as he has a plausible biological model that he is not only allowed to do all these things, he said that he is even allowed to use these cherry-picked univariate correlations as EVIDENCE that his hypothesis is correct. See the quote below from his article A Primer on Statistics (http://www.campbellcoalition.org/?page_id=203)

    “In summary, I agree that using univariate correlations of population databases should not be used to infer causality, when one adheres to the reductionist philosophy of nutritional biology and/or when one ignores or does not have prior evidence of biological plausibility beforehand. In this case, these correlations can only be used to generate hypotheses for further investigation, that is, to establish biological plausibility. If in contrast, we start with explanatory models that represent the inherent complexity of nutrition and is accompanied by biological plausibility, then it is fair to look for supportive evidence among a collection of correlations, especially when we examine these correlations from multiple biological perspectives.”

    You also really should read Minger’s latest paper. She doesn’t take the time to harp on and explain every issue as much, but she hits a broard array and really dismantles the “animal products are unhealthy” hypothesis as argued by Campbell.

    A final issue to remember is that while Campbell does have many scholarly papers, the China Study is just some book where he is arguing his hypothesis. He has also indicated that in many ways he is approaching science from a newer, holistic viewpoint (one where he can cherry-pick simple univariate correlations as evidence…) that he himself recognizes that might not be well accepted or appreciated by other scientists. I think you need to be skeptical of attaching too much weight to his scientific credentials in cases such as then when he himself acknowledges that he is stepping out of the mainstream.

  41. brett99 says:

    Hi JonM:

    Thanks very much for your detailed comments. You’ve made a lot of good points. I’ve done some more checking and, I must admit, I’m growing more skeptical about Dr. Campbell’s recent work in light of what Harriet and others (including yourself) have written. He really “indicated that in many ways he is approaching science from a newer, holistic viewpoint”? If that’s the case, then yikes, that is a bit of a death march to camp Pseudoscience.

    “If in contrast, we start with explanatory models that represent the inherent complexity of nutrition and is accompanied by biological plausibility, then it is fair to look for supportive evidence among a collection of correlations, especially when we examine these correlations from multiple biological perspectives” – yes, I agree for sure, this is a credibility-disintegrating admission. Ouch.

  42. Results-count-most says:

    Having been a student of statistics, it comes as no surprise to me that studies are designed, or data is used selectively, to fit a particular hypothesis. Given my background, I am sceptical that Dr. Minger, or even Dr. Hall, is free of bias.

    Let’s assume for a moment, that Dr. Minger’s statistical interpretation is “better” than Dr. Campbell’s concerning the dangers of eating meat and dairy. How does anyone explain away the positive results that so many doctors are enjoying AFTER they affect dietary changes in their patients to move them away from meat and dairy? For your ease of reference you can refer to Dr. Neal Barnard or Dr. John A. McDougall. Lastly, how can we claim there is equal benefit to humans eating meat and dairy when fairly recent scientific research uncovered the molecule Neu5Gcwhich comes from those sources of food and that may have harmful affects? Based on the SCIENCE of THOSE researchers and the many others publicizing this molecule, we are the only mammals that can not digest that molecule–from meats and dairy–and our bodies react NEGATIVELY to it. From the attached link (site), I quote: when we eat red meat, Neu5Gc still gets picked up by our epithelial cells and presented on their surface, but our immune system recognizes it as foreign and therefore dangerous. (Ref.: http://www.cancerresearch.org/RealStories/Scientists/Oliver-Pearce.html ) Maybe Dr. Campbell had much to much to review concerning pure statistics, but he knew he was on to something healthy and positive for humans by trying to compile such extensive data into a layman’s guide to justifying the avoidance of meat. I continue to salute Dr. Campbell and would suggest that Dr. Hall and Dr. Minger contact Dr. Campbell and professionally discuss the statistics in a forum conducive to such critical reviews.

  43. Patrick N says:

    Miss Minger is not a doctor, but she has a great scientific mind none the less.

    She has recently made available online a much more formal analysis of the data: http://rawfoodsos.com/2010/08/06/final-china-study-response-html/

    Quote: “If both whole-food vegan diets and non-Westernized omnivorous diets yield similar health benefits, this is a strong indication that the results achieved by McDougall, Esselstyn, Ornish, et al are not due to the avoidance of animal products but to the elimination of other health-harming items.”

    This I believe is the important take home message. The data is not saying that vegan is not healthy, it is simply showing no evidence that eating meat is unhealthy.

    Patrick

  44. JonM says:

    Hi Results-count-most,

    By referring to Minger as “Dr. Minger” it is apparent that you are not really paying attention. That is actually a common problem for the people supporting Campbell. They need to pay more attention. If you were to read Campbell more closely, you would see that his scientific rationale is the same as Creation Science.

    In many ways, the bigger issue is not the statistics but the reasoning Campbell has provided in support of his use of the statistics. He claims to use a superior holistic type of science. Because he has a biologically plausible model (i.e. hypothesis), he claims he can pick and choose whichever simple univariate correlations he wants as evidence that his hypothesis is correct.

    This is the same thing as what Creationists do. They have a hypothesis that they really like (the world is 6000 to 10000 years old), and they pick and choose whatever “evidence” they want to support this and disregard everything that does not support this.

    Campbell has also used his own hypothesis to discount and disregard the results of major studies like WHEL, PPT, and EPIC that showed plant foods are not that impressive at preventing disease.

    This has been Campbell’s response to critics since the beginning. When Chris Masterjohn, Minger, and others have brought up contradictory correlations and pointed out flaws in his use of simple univariate correlations, Campbell has talked of them using “uncorrected,” raw correlations. In turns out what he means by “uncorrected” is that his critics are not putting forward a biologically plausible model (i.e. hypothesis) to support theses correlations (even though all they are doing is criticizing Campbell’s use of these simple correlations).

    Campbell claims that since he does have a biologically plausible model that his own simple univariate correlations are “corrected.” In other words, his own hypothesis justifies which correlations can be used and which cannot. Not only can he cherry-pick his correlations and ignore contradictory ones, he can also ignore confounding variables and ignore his own more sophisticated statistical analyses. You can see this logic expressed in Campbell’s own words in the quote I listed in my earlier comment.

    This is not how science works. That is how Creation science works. It is very unfortunate that Campbell, all wrapped up in his past scientific credentials, is actually trying to teach people that this is a superior form of science.

    Campbell’s abuse of science has been the main critique by many. The “meat hypothesis” is secondary. He has constantly made appeals to authority talking about all of his credentials and research experience, but when it comes to peddling his hypothesis he has resorted to pseudo-science, hand-waving, and lying (“casein is the most relevant chemical carcinogen we ever tested” when lysine-fortified wheat had the same effect.)

    And all of that does not bode well for his “meat hypothesis.” If meat were so clearly bad for you, you would think someone with such credentials could do better than resorting to pseudo-science, hand-waving, and lying. Even freely cherry-picking simple univariate correlations, he could not find any that directly implicated meat. He had to use questionable intermediate variables to string along a correlation. This does not mean that his meat hypothesis is incorrect, but like I said, it does not bode well. And it surely does not provide a scientific basis for avoiding meat as many attempting to influence public policy have proclaimed.

    As far as McDougall and others having success with a similar diet program, Minger points out in her latest post that these programs all limit sugar and processed foods. Maybe everybody should get on that message instead of worrying about meat and saturated fat. The Masai and Inuits have done fine eating a lot of meat, but the problems come with sugar and processed foods.

    Another issue to consider also is that along with Campbell, McDougall and others are often not doing science anymore; they are selling a message. The Campbell Coalition website openly admits that it censors dissenting views. There has been suggestions that McDougall’s website does the same. This is what happens when you push a message rather than worry about the science. People need to realize that Campbell may have been a scientist at one time, but what he is doing now is anti-science.

    As far as Neu5Gc, it is interesting, but you are still talking about hypotheses that need to be tested. In Campbell’s new holistic (Creationist…) science, hypotheses don’t need to be tested, but in real science they do.

  45. BigJeff5 says:

    For anybody interested in where Denise Minger is coming from with regards to being a “plant eater”, as Campbell refers to vegitarians, or a meat eater, as a low carb or paleo proponent would see it, she is neither.

    Check out here “About Me” page here:
    http://rawfoodsos.com/about/

    She subscribes to a raw-foods diet, meaning no processed foods at all and no cooked meats. She would be vegitarian except she eats a little to much meat. She would be paleo except she eats too much fruit.

    She is least likely person to have an alterior motive, and so is in the perfect position to look at a study like this. Amateur she may be, but she is a statistics nut, and definitely knows how to analyze and interperet statistical data, and how much you can actually get out of it.

    It is in this context you must view her analysis, and analysis ripped Campbell’s sloppy work to shreds, while at the same to continuing to stress that her own analysis does not prove that animal foods are health either. This is because, as apparently every scientist but Campbell knows, correlation cannot prove causation, and as such observational studies (which are entirely correlative) cannot be used to show any cause. They can merely serve as a starting point to form hypothesis which can then be tested much more rigorously.

  46. confluence says:

    there are a lot of independent studies that support a largely plant base diet with grains and fruits and restricted meat.

    1. The blue zone.
    2. China study
    3. Latest findings from the calorie restriction research that support a protein restricted diet does indeed enable a longer and healthier life.

    Each of the source is a classic/ major breakthrough in its own field and taken together it make compellling argument for a vegetarism base diet.

    So there it is. Make of it what you will and you can debate endlessly about tiny details about isoteric math correlelation but I rather go on the larger picture from a overall broader perspective.

  47. CPM says:

    Hi Confluence,

    The “tiny details about isoteric math correlelation” are not really that tiny or esoteric. It is rather straightforward. Campbell claims that in his new holistic science that he can cherry-pick simple correlations and use these as proof that his hypotheses are correct. This is hocus-pocus pseudoscience in the same league as Creationism.

    As has been mentioned above as well, Campbell continues to state that “casein is the most relevant chemical carcinogen we ever tested,” when in fact his group got the same results with lysine-fortified wheat. So not only is The China Study filled with hocus-pocus pseudoscience, it is filled with blatant lies.

    Unfortunately, The China Study is a “classic/ major breakthrough in its own field” when the field is ‘pseudoscientific books that encourage and teach the public to ignore proper science.’

  48. nory says:

    @ Brett99
    Appreciate your careful statements. That is what I’m looking for.

    Mike Anderson’s video “Healing cancer from inside out” (attacking conventional therapy of cancer) seems to confirm that Campbel has jumped on the pseudoscience wagon. (the video is sold on Amazon and downloaded from thepyratebay.org).

  49. Suzubick says:

    When I read The China Study, I was somewhat underwhelmed; the very first thing that caught my attention was the questionnaire, which had nothing at all about entomophagy, still a very important protein source across Asia. Entomophagy is something I’m interested in, though I’ve concluded (after taste tests, maybe I’m too western), it’s not for me. However, I think there’s huge potential in breeding insects as protein sources for chickens and pigs, for example – get carcass and blood meal, as well as fish meal, out of their diets. Anecdotal evidence for entomophagy: my spouse is an arachnologist; he spent several weeks in China in 2000. The group travelled throughout Yunan and Hunnan provinces. My spouse will eat anything; he has a notebook recording species he has eaten. In China, he ate locusts, cicadas, wasp and ant larvae and pupae; these were freely available at guest houses, restaurants, and in markets as street food. Other arthropods, like scorpions, are also very popular. I know I’m belabouring the obvious, but insects are animals. It reflects poorly on Campbell that he did not take entomophagy into account in his studies. Is he not aware of the practice? Too revolted as a westerner to take it seriously?
    http://people.howstuffworks.com/entomophagy.htm
    http://www.food-insects.com/2006addsOct.html
    http://findarticles.com/p/articles/mi_m1200/is_18_173/ai_n26674825/

    I decided to check Campbell’s assertions through outside evidence, figuring that if his claims were genuine, they’d be reflected in official figures.

    This is what I found: Official data do not support The China Study’s claim of uniquely good health among rural Chinese. Source: World Health Organization. The USA comes in at #37, right at the bottom of the developed nations. China comes in at #144. That’s out of 190 countries, and the data are from 2007. The China Study was published in 2005, and its data are about 40 years old. Here’s the WHO’s ranking: http://www.photius.com/…/healthranks.html

    According to the Chinese Ministry of Health, the Chinese have the world’s highest incidence of stomach cancer, other cancers occur at about the same rate as in the US, AND the Chinese have a fatal stroke rate FIVE times as high as in the USA. Examining the Chinese Ministry of Health report more closely, rural Chinese have cancer and stroke rates NINETEEN TIMES as high as Chinese city dwellers. http://www.chinadaily.com.cn/…/content_6652952.htm

    Diabetes? China describes it as an epidemic. news.bbc.co.uk/…/8587032.stm; http://www.sciencedaily.com/…/100324174057.htm

    Just one study, of the multitude available:
    A study by Longde Wang, Lingzhi Kong, Fan Wu, Yamin Bai, and Robert Burton, published in the Lancet 2005; 366: 1821-24. http://www.sas.upenn.edu/…/ChronicDiseaseChina.pdf

    “Chronic, non-communicable diseases now account for an estimated 80% of total deaths and 70% of total disability-adjusted life-years (DALYs) lost in China (figure 1). The major causes of death in China are cardiovascular disease, cancer, and chronic respiratory disease. Rates of death from chronic disease in middleaged people are higher in China than in some high income countries.”

    It is a real stretch of the imagination to conclude from this that all the sickness in China is found among animal-source-food-eaters….

    Now, this is rather strange to me. Campbell deliberately selected rural people, on the grounds that they had been generationally resident in particular areas and would be eating food close to ancestral eating patterns. Yet he did not address the question of whether people, long-resident in a particular region and eating a particular dietary pattern, might become biologically adapted to a high-carbohydrate low-animal-protein diet. As a researcher who frequently uses rats specifically bred for, e.g. cancer susceptibility, surely the thought should occurred to him? Thorough discussion of this aspect would have been valuable, along with reasons for dismissing it as a factor. Gary Nabhan’s book, “Why Some Like It Hot,” is very well worth reading in this regard, as also Michael Pollan’s “Botany of Desire.”

    Campbell also overlooks the strong selective influences (aka natural selection) of biogeography and actually of history! China is notorious for its famines; obviously the weaker individuals die first. The ones most likely to survive and breed are those with the lowest requirement for total energy, and the best metabolic ability to digest foods with high carbohydrate content. Some legumes are 80% starch, after all. Famine in China: http://en.wikipedia.org/wiki/List_of_famines_in_China
    http://en.wikipedia.org/wiki/Famine (scroll down)

    Then there’s the question of data reliability. Campbell says of the Tuoli data that they’re unreliable because the people must have tried to show off to the researchers by consuming unnaturally high amounts of animal source foods during the three days the researchers were present, and that they lied on the questionnaire to impress the researchers. (How does he know this for certain?) Plus, if the Tuoli group lied, it immediately begs the question of how Campbell knows for certain that none of the other villages did the same, perhaps in reverse? It’s the bane of anthropologists; target groups will try to make themselves look good to the researchers!! Create an impression that you think that apple-eating is a mark of intelligence, and boom! everybody’s an apple-addict! Exude an aura of apple-disapproval, and suddenly the fruit is concealed and lies told. The whole sexy Samoa/Margaret Mead debate is based on this point, the tendency of target groups to say what they think the researcher wants to hear. And Mead was in Samoa longer than Campbell was in any one village!

    The more I looked into it, as a layperson, the more I became worried. How can one possibly project the results of feeding purified casein isolate onto all animal proteins? The rats weren’t given whole liquid milk. Why weren’t the results of the lysine-supplemented wheat given full prominence as an equally potent carcinogen?

  50. rnikoley says:

    Hi folks.

    In case you didn’t know – and I somehow only got wind of this post today – Denise is in a podcast interview just published yesterday. Link is at my blog, freetheanimal.com

    Something else. Chris Masterjohn, one of the two guys, along with Anthony Colpo who did reviews of TCS way back when has been invigorated by Denise’s posting and has gone back and piled through his earlier controlled studies.

    http://www.westonaprice.org/blogs/the-curious-case-of-campbells-rats-does-protein-deficiency-prevent-cancer/blogger/CMASTERJO/

    Essesntially, he shows that Capbell generated good and strong evidence that protein deficiency could lead to cancer in rats, and it was even labelled as such: protein deficiency.

    How things change.

  51. busandunk says:

    I’m interested to know if Harriet Hall has seen or acknowledged the rebuttals that Colin Campbell has posted. Is she willing to concede the many errors in Denise Minger’s huge critique? including the observations from the cancer epidemiologist showing the basic amateur mistakes in Denise’s work. It seems just bizarre that she is taking her cues from a 24 yr old journalism student who ‘loves numbers’ against the internationally respected Campbell with literally hundreds of peer-reviewed articles to his name and decades of research behind him.

    The misrepresentations of Campbell’s points are all over the internet. Zombie arguments that have already been dealt with keep popping back up – is Harriet Hall unable to distinguish an internet propaganda campaign from serious science? The vitriol against Campbell and his conclusions is enormous (and almost always from non-scientists)..

    Have any proper scientists pointed out serious errors in Campbell’s work? – and not just relied on highly biased internet blogger critique who has stated they will not submit to the peer review process?

  52. CPM says:

    Hi busandunk,

    Have you bothered to read any of the comments here at all? Or are you just here just doing your part as a soldier of pseudoscience?

    The claims in Campbell’s popular diet book are not peer-reviewed science, so why do you claim that a critique must have that requirement? How many of the articles here on Science Based Medicine are published, peer-reviewed science papers? It is a silly argument that you have to do a peer-reviewed scientific paper to ridicule pseudoscience.

    I know that the vegans like to create the strawman argument that Denise did her own study and found that “meat was good,” but all she did was attack the way Campbell abused science in reaching his conclusions. It is just an attack on bad science.

    The anonymous, self-proclaimed “cancer epidemiologist” that you mention apparently has a severe lack of reading comprehension ability. She is also a member of and strong supporter of a vegan group called “30 Bananas a Day” that endorses a mostly fruit diet where you gorge yourself on fruit all day, so she might be a little biased as well. (You claim that Minger is “highly biased”, but she eats a mostly vegetarian-style diet herself that Campbell would probably endorse.)

    Minger was critiquing Campbell’s methods and interpretations, not doing her own epidemiological study or reaching her own conclusions. Minger just demonstrated (using hard numbers) that Campbell cherry-picked simple univariate correlations, ignored confounders, ignored his own multivariate analyses, and used questionable intermediary variables to string along correlations.

    Whether through idiocy or bias, the “cancer epidemiologist” created a strawman argument that Minger performed her own epidemiological study and drew her own conclusions that “meat was good.” Every supposed flaw she found in Minger’s strawman “study” was in fact a flaw in Campbell’s very own epidemiology. This should be pretty obvious to anyone that was paying attention.

    It is much more than just bad science though, Campbell fully endorses pseudoscience as the scientific rationale behind the China Study. I would love for the “cancer epidemiologist” or any epidemiologist to try and defend Campbell’s claim that the common refrain of “Correlation is not Causation” does not apply to his new holistic science that he uses in the China Study.

    This is from Campbell’s “Correlation vs. Causation” article proudly displayed on the front page of his website. (It is also proudly displayed as a “Primer on Statistics” at the 30 Bananas website where the “cancer epidemiologist” posts.)

    “In summary, I agree that using univariate correlations of population databases should not be used to infer causality, when one adheres to the reductionist philosophy of nutritional biology and/or when one ignores or does not have prior evidence of biological plausibility beforehand. In this case, these correlations can only be used to generate hypotheses for further investigation, that is, to establish biological plausibility. If in contrast, we start with explanatory models that represent the inherent complexity of nutrition and is accompanied by biological plausibility, then it is fair to look for supportive evidence among a collection of correlations…”

    This is the entire basis of his use of statistics in the China Study. He says quite clearly that the common refrain of “Correlation is not Causation” only applies to suckers performing “reductionist” science, but if on the other hand you adopt a superior, holistic kind of pseduoscience that Campbell has embraced, then you can cherry-pick any simple univariate correlation that you find convenient and use it as proof that your hypothesis is correct. Any epidemiologists in the audience want to stand behind this?

    For analogy, if you have a hypothesis that the Earth is only 7000 years old, then using Campbell’s style of new, holistic “science” you can freely disregard dinosaurs and radiocarbon dating. Those would be called “uncorrected” correlations in Campbellian “science”.

    You could, in fact, using Campbell’s brand of science, pick whichever correlation fits your hypothesis then turn around and say that very same correlation helps prove that your hypothesis is correct. Kind of circular maybe? Kind of disturbing maybe to use simple univariate correlations to prove hypotheses rather than generate them?

    Back when Chris Masterjohn and others tried to point out the problems of Campbell’s simple univariate correlations, in his defense Campbell would start talking about “corrected” and “uncorrected” correlations (or “adjusted” and “unadjusted”). It turns out Campbell did not define “corrected” as multivariate analysis or an analysis that included confounders. All “corrected” means to Campbell is that it supports his hypothesis. “Uncorrected” correlations would be like dinosaurs – they don’t fit the hypothesis so they are disregarded.

    Is that how epidemiology is performed – you use your own pet hypothesis to judge what correlations are “corrected”? Is there anyway one could nullify their own hypothesis using this approach? Is it really science if you cannot nullify your own hypothesis?

    To top it all off, Campbell’s and his supporters’ main defense all along has been “Hey, I’m a great scientist”. What kind of “great scientist” so fully wraps himself in pseudoscience just to publish a diet book and continues to tout it as a new kind of holistic science? What kind of people defends and endorses this?

  53. sara says:

    With all due respect to Ms. Minger, who is this person and furthermore, why should I care? So much of the criticism of Dr. Campbell I have seen has come from people who are bloggers posing as “independent researchers” who have no degrees in medicine, science, nutrition, mathematics, or anything else. Maybe they are trying to make a name for themselves and attract some attention to their blogs? Just a thought.

    I have no question that these critics are intelligent people but actually promoting them for any reason whatsoever is kind of questionable in my opinion. Again, this is just my opinion so no flames from everyone who might want to come out of the woodwork to talk about how brilliant she is.

    The field of nutrition is indeed confusing. I don’t know if Campbell proved anything from the China Study but I do feel great when I eat more plants. :)

    -s

  54. Suzubick says:

    “From the attached link (site), I quote: when we eat red meat, Neu5Gc still gets picked up by our epithelial cells and presented on their surface, but our immune system recognizes it as foreign and therefore dangerous. (Ref.: http://www.cancerresearch.org/RealStories/Scientists/Oliver-Pearce.html )”

    Good heavens! And to think our ancestors ate that nasty molecule for 5 million years…

  55. Suzubick says:

    Somebody on this post asked if any proper scientists had published anything rebutting Campbell’s conclusions. The answer is, “Yes.”

    Hu FB, Willett WC. The relationship between consumption of animal products (beef, pork, poultry, eggs, fish and dairy products) and risk of chronic diseases: a critical review. Cambridge, MA: Harvard School of Public Health, 1998.

    Vegan Outreach quotes part of the summary of this paper on its website, as part of its warning against using the health argument for proselytizing. http://www.veganoutreach.org/articles/healthargument.html.

    This is what Hu and Willet said:
    “The effects of animal products on risk of chronic diseases are an area of considerable controversy.… [I]nternational correlations between per capita food consumption and disease rates are seriously confounded by other lifestyle factors associated with economic affluence.… One of the most comprehensive correlational studies conducted within a country is the China-Oxford-Cornell study.… These correlations, although informative and valuable in many ways, cannot be used to establish causal relationships between dietary factors and disease risk. The limitations of geographical correlations were precisely stated by Drs Doll and Peto:

    Trustworthy epidemiological evidence, it should be noted, always requires demonstration that a relationship holds for individuals (or perhaps small groups) within a large population as well as between large population groups. Correlation between the incidence of cancer in whole towns or whole countries and, for example, the consumption of particular items of food can, at most, provide hypotheses for investigation by other means. Attempts to separate the roles of causative and of confounding factors by statistical techniques of multiple regression analysis have been made often, but evidence obtained in this way is, at best, of only marginal value.

    “Indeed, some of the correlations produced from the China-Oxford-Cornell study are peculiar and probably incorrect. For example, esophageal cancer had no clear association with smoking, and had a negative correlation with daily alcohol intake. These results are clearly contradictory to the well-established findings from studies of individuals that both smoking and alcohol use are strong risk factors for esophageal cancer. In addition, the study did not find a clear association between meat consumption and risk of heart disease or major cancers.”

    The last line bears repeating: “In addition, the study did NOT find a clear association between meat consumption and risk of heart disease or major cancers.” (emphasis added).

    There is much material of interest here: http://www.beyondveg.com/billings-t/comp-anat/comp-anat-8e.shtml

    Note that Campbell, in scientific papers with co-authors, correctly states that correlation is not causation, and that it is inappropriate to extrapolate datasets from one population to another. Yet, in his book, Campbell does exactly these things. So if it’s bad science in a peer-reviewed publication, is it also bad science in a book written for general reading?

    There’s also this article, http://www.cathletics.com/articles/proteinDebate.pdf, in which Drs. Campbell and Cordain debate protein requirements for humans. Note that Campbell offers no references at all, so there is no way to check up on his statements. Cordain makes this very valid point while conducting a detailed analysis of Campbell’s argument. Cordain does cite references. While these references could be cherry-picked to support his own argument, the same option was available to Campbell. He could have assembled references to back up his statements; without them, his argument is reduced to a personal opinion piece.

    Campbell himself co-authored a paper describing the way that plant protein, gluten, when supplemented with lysine to make it a complete protein, accelerated tumor growth in the same way as high doses of casein. That seems to indicate that rice-and-beans are as dangerous as casein, as each makes good the deficiencies of the other. Caveat: the cancer was NOT caused by the casein. Campbell used rats specifically bred for susceptibility to cancer, then repeatedly injected them with aflatoxin to ensure that they got cancer. Here’s the link to the gluten/lysine paper: http://jnci.oxfordjournals.org/content/81/16/1241.abstract

  56. Suzubick says:

    Hu and Willet again: http://www.ajcn.org/cgi/content/full/71/3/850

    Note this comment: “Campbell suggests that the independent effects of various nutrients cannot be teased out because of their high correlations.”

    In that case, it isn’t possible to single out animal protein as detrimental…he can’t have it both ways!

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