Carcinogenicity of casein

[TanneryGulch]

People, please. I just want to talk about nutrition and learn from all of you without making enemies (or friends, for that matter). I've asked a simple question here. If you can help answer it, please do; if not, please just move along. This is a medium that gives you complete control over what you spend time reading.

Jim, I suppose, given your history, it was only a matter of time before you tore into me personally too. I'd just ask you to consider that in previous posts I've:

- thanked you for your thoughtful remarks
- called you smart
- called you right and myself wrong

all very sincerely. The worst thing I've said to you was asking you nicely to stop abusing other members. Anyway, I think readers can see for themselves that your attempt to project your own nasty behavior onto me is baseless, that I haven't stooped to anything like your ongoing pattern of personal attacks and demagoguery, and that you're the one, not me, who's been picking fights from your very first post: http://drmcdougall.com/forums/viewtopic ... 8635#68635

I don't doubt that Dr. McDougall described "support" as an essential function of his board; of course it is! The question is whether he meant it in the restrictive sense you and Karin invoke to claim that he meant to prohibit discussion (for which you still haven't offered a shred of evidence). In any case, you anti-debaters have stated your opinion at least 10,000 times. Must you reiterate it in response to every last Heretic post? Sheesh.


Edit: Karin: Anna points out below my insulting use of "delusional" (of your claim, not you personally, although I admit the distinction is pretty fine). Sorry; I felt frustrated and made a bad choice of words. I meant only to say that you'd made an unsubstantiated claim, not to get personal or suggest that you actually suffer from delusions in the clinical sense. Please accept my apology.

[TanneryGulch]

Anyway, back on topic...

Jim, thanks for the studies you linked, which I think are on target:

#1 (Dave): This one seems to go against Campbell's generalization from casein to animal protein (my #2 question), since whey was relatively protective vis-à-vis casein.

#2 (Oliviera) and #4 (Zhang): Heretic, put these on your list to address, too, since both found promotion of cancer by casein without aflatoxin as the initiating carcinogen.

#3 (Corpet): Honestly, I don't understand this one. (Was uncooked casein one of the controls that didn't promote cancer?) In any case, you've got significant dietary control of cancer development with casein in play and an initiator other than aflatoxin.

[xetaprime]

Even with all the yapping theres learning to be had here

[Yoga Nurse]

Hi,
I'm glad that Tannery is not trying to make friends on this board as calling Karin delusional probably won't serve to increase the chances of that happening. (Just my personal observation- call me nutty if you like...)

This discussion however, is of interest to me. Dr. Campbell discusses the fact that exposure to hepatitis b virus leads to liver cancer only in the presence of animal protein. I was (strongly) encouraged to have this vaccine as I am a health care professional so as to avoid infection with hepatitis b and the resulting possibility of liver cancer. The vaccine led to severe RA (rheumatoid arthritis- that's the inflammatory, disabling type of arthritis for those not familiar.) Had I known at the time that hepatitis b would do so (lead to liver cancer) only if I ingested dairy and other animal proteins, I would never have gotten the shot and would have saved myself years of pain and disability. Fortunately, if I stay very strict with Dr. McDougall's recommendations, I am healthy, happy and pain-free. Not a bad trade-off, really.

Avoiding dairy completely (and following Dr. McDougall's other recommendations) also has lowered my cholesterol into the 130's (I was a vegetarian and it was in the 160's before), saves me from fear of heart disease, stroke (I am at higher risk than the general population due to migraine), the common forms of cancer (oh, isn't this where we started?), and probably lots more. I know, I've gotten off the subject. Ah well....

Anna

[Heretic]

...

FIGURE 1: Associations of Selected Variables with Mortality for All Cancers
Carbohydrates +23% [HIGHEST CORRELATION WITH CANCER]
Fiber +21%
Total Calories +16%
Total Protein +12%
Plant Protein +12%
Fish Protein +7%
Animal Protein +3%
Total Lipids -6%
Fat % Calories -17%
Fat(questionnaire) -29%* [MOST NEGATIVE CORRELATION WITH CANCER]
(*=statistically significant)
Capitalized text in square brackets are my comments.
Stan (Heretic)
---------------
Junshi, Chen, T. Colin Campbell, Li Junyao, and Richard Peto, Diet, Life-style and Mortality in China: A Study of the Characteristics of 65 Chinese Counties, Oxford: Oxford University Press, 1990

Stan, the actual book I think you're referring to is "Mortality, Biochemistry, Diet and Lifestyle in Rural China: Geographic Study of the Characteristics of 69 Counties in Mainland China and 16 Areas in Taiwan" published in 2006.

This book is simply raw data tables and anyone with half a brain knows that looking at a single table means nothing, especially out of context. You are in possession of a full brain and therefore know that doing this kind of thing is manipulative and done only with the intention of making a point that cannot be made with a fuller picture.

Raw data means everything, it shows the truth. And the truth is that none of the proteins were statistically significantly associated with cancer, in the China Study, while the only food that significantly correlated inversely with cancer was fat!

Even if you wanted to accept non-significant data (below one sigma or whatever multiple they used) then you ought to notice that carbohydrates correlated twice as much with cancer than protein, any kinds of protein!

Saying publicly that animal protein causes cancer and bringing Campbell's book as supposedly in support while at the same time ignoring the raw data table from his publication is not scientifically acceptable. You are massaging the facts picking bits from his work that support you while rejecting those that don't. Interestingly Campbell himself seems to be doing exactly the same thing; why then are you so surprised that I am less than enthusiastic about Campbell's book especially if I had to pay money to buy it?

Unless you're going to say that Campbell is deliberately misleading people with fraudulent interpretation of the data,...

You said that first! I am inclined towards that possibility although I am not 100% sure what his true motives may be. One thing I did notice - he seems to have a very strong drive towards validating the pure veganism and at the same time denigrating any kinds of animal produce, so much as to willing to ignore all evidence to the contrary.

... then The China Study should be regarded as what Campbell believes as a result of his entire career in the field - including interpretation of all the data and tables in that book. His position on animal protein (not just casein) is quite clear and based on many forms of protein.[/b]

Science is not based on honoring one's life career but on showing the data and drawing logical conclusions.

You are only partly right about the casein - that was the protein in the rat studies. However, the human observations that prompted the rat studies showed a relationship between cancer formation in response to aflatoxin and total animal protein intake - not just casein.

Then please show those studies!
That's exactly why I think Tannery asked for those studies. I also would like to see the studies, so far I have sifted through F1Jim's links and none of those seem relevant.

In The China Study, Campbell very clearly implicates animal protein in general (not just casein, which was not generally consumed by the Chinese in the study) as a primary factor that affects cancer and mortality. Animal protein intake even at the very low levels consumed by the Chinese (relative to Americans) had a strong correlation.

Campbell's own data (see the table quoted above) does not support your statement! That is the main reason behind my distrust of Campbell's words. Once his statements are shown to be inconsistent, why should I trust his overall work? It's a matter of scientific credibility. Once a scientist looses it, it is virtually impossible to regain.

[f1jim]

Heretic knows how to manipulate the data better than anyone I know. His use of this table is the perfect example. He has been discredited on this point on other forums but we are "new blood" to him. I will refrain from an all out fight, for the boards sake, but here is his error in a nutshell.
When you use broad tables we get broad errors. If I made the statement that 80% of all serial killers ate bread within 48 hours of their crimes we would all see the foolishness of that claim. Probably 80% of all people EVERYWHERE have eaten bread in the last 48 hours. Go back to the table and see that he injects the comment that carbohydrates are highest in correlating with all cancers. Would it not be a safe assumption that everyone probably consumed carbohyrates? Notice this is also a chart relating to all cancer mortality. Think about that for a minute. When we think about meat consumption do we think about lung cancer? Skin cancer?
Of course not but that is what the TOTAL CANCER MORTALITY refers to....ALL CANCERS. Now if we break out the correlations to say, cancers of the colon or other parts of the lower digestive tract, we would see the same type of correlations we do in many of the studies of individual cancers (some I have linked to here in the past). This is exactly the way tobacco companies confounded the data making it look like there was no link to smoking and lung cancer. Just show the data linking smoking and ALL CANCERS and the link is insignificant. Heretic has always played fast and loose with his choice of supportive data. I promise to let this go now.........promise!
f1jim

[Heretic]

http://www.ncbi.nlm.nih.gov/pubmed/16614397?ordinalpos=6&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum

http://www.pubmedcentral.nih.gov/articl ... tid=275444

http://cancerres.aacrjournals.org/cgi/c ... 50/21/6955

http://jnci.oxfordjournals.org/cgi/cont ... 026?ck=nck

f1jim

#1. It is not relevant to our discussion. This papers shows that whey protein is protective against DNA damage as opposed to casein but it does not really address the issue whether casein is good or bad, neither it addresses the isssue whether animal proteins are bad in general.

#2. The title itself (β-casein-derived peptides, produced by bacteria, stimulate cancer cell invasion and motility) does not indicate that the paper may be relevant to our topic. Further in the text the authors state "Bacteria participate in colon cancer development. ...". Since bacteria are the main cancer inducing agent in that study, would it not warrant perhaps to look at a correlation between gut bacteria and colon cancer? What exactly do gut bacteria typically feed upon? To facilitate the answer I will present it in form of a quiz: A-Fat, B-Protein, C-Carbohydrates ?

#3. "Promotion of Colonic Microadenoma Growth in Mice and Rats Fed Cooked Sugar or Cooked Casein and Fat". This isn't very relevant either. The paper concluded:
The results suggest that a diet containing sucrose cooked to
the consistency of hard caramel (Diet B) and a diet containing
casein and beef tallow cooked together (Diet G) can act as
promoters of colon carcinogenesis.
It doesn't say that other protein (for example plant protein) cooked with beef tallow would or would not cause similar problem. They also showed that it probably cannot be the beef fat alone because diet D was less cancer promoting. So much for the "fat is bad" theory, eh?

#4. "Promotion of Aberrant Crypt Foci and Cancer in Rat Colon by Thermolyzed Protein". Quote: "Conclusions: Thermolyzed: casein promotes early colonic precursor lesions in a dose-dependent and thermolysis time-dependent manner" Then don't thermolyze casein! This is yet another argument against homogenization or pasteurization of milk. However I still don't know whether that is specific to casein, and not to other types of protein, including plant protein as well. Please keep in mind that we HAVE to eat some proteins, you cannot just live off your favored carbohydrates alone! Again this paper does not resolve that issue, that is, is caseine worse than other protein or isn't?

[Heretic]

Heretic, I've got to agree with Landog on this one: you haven't even read the book??

Anyway, here are Campbell's cites:

Transgenic HBV + casein == liver cancer
Hu J, Cheng Z, Chisari FV, et al. "Repression of hepatitis B virus (HBV) transgene and HBV-induced liver injury by low protein diet." Oncogene 15 (1997): 2795-2801.

Cheng Z, Hu J, King J, et al. "Inhibition of hepatocellular carcinoma development in heptatits B virus transfected mice by low dietary casein." Hepatology 26 (1997): 1351-1354.


Chemical carcinogens + casein == breast cancer
Hawrylewicz EJ, Huang HH, Kissane JQ, et al. "Enhancement of the 7,12-dimethylbenz(a)anthracene (DMBA) mammary tumorigenesis by high dietary protein in rats." Nutr. Reps. Int. 26 (1982): 793-806.

Hawrylewicz EJ. "Fat-protein interaction, defined 2-generation studies." In: C. Ip, D. F. Birt, A. E. Rogers and C. Mettlin (eds.), Dietary fat and cancer, pp. 403-434. New York: Alan R. Liss, Inc., 1986.

Huang HH, Hawrylewicz EJ, Kissane JQ, et al. "Effect of protein diet on release of prolactin and ovarian steroids in female rats." Nutr. Rpts. Int. 26 (1982): 807-820.


Fish protein similarly carcinogenic to casein
O'Connor TP, Roebuck BD, Peterson F, et al. "Effect of dietary intake of fish oil and fish protein on the development of L-azaserine-induced preneoplastic lesions in the rat pancreas." J Natl Cancer Inst 75 (1985): 959-62.

(This one was really comparing n6 to n3 fat, but it is suggestive of an answer to my #2 question.)

I wasn't able to find Huang,Hawrylewicz studies. The other studies are:

1 and 2) "Inhibition of hepatocellular carcinoma development in hepatitis B virus transfected mice by low dietary casein."

Repression of hepatitis B virus (HBV) transgene and HBV-induced liver injury by low protein diet

I would agree with the study: limiting casein (or perhaps other proteins though the authors didn't analyze that) may be beneficial. Please keep in mind that I consume only 10% of calories out of protein! However I still don't know if casein is worse than other proteins. May well be but the study didn't show it.

3) "Effect of dietary intake of fish oil and fish protein on the development of L-azaserine-induced preneoplastic lesions in the rat pancreas."

The study concluded:
This study provides evidence that fish oils, rich in omega 3 fatty acids, may have potential as inhibitory agents in cancer development.

and I would agree with that! Still, it hasn't shown that caseine is better or worse than other protein.

I have a general comment: - if you feed any kind of food (even water) in excessive quantities you may potentially cause problems and enhance some health risk. If they feed rats a diet consisting exclusively of a small number of ingredients such as almost all protein in form of just one type (either caseine or whey) and almost all carbohydrates in form of just two (starch and dextrine) and all fat in form of corn oil then it is not surprizing that they may observe some weird things. That's typical among the rats' studies. Furthermore, if you feed an excessive amounts of any single one ingredient beyond the normal physiological needs, you may also see strange artifacts that may tell you nothing about the intrinsic nutritional value - that's why I pointed out at that 5%-20% casein "switching" effect as the tell-tale sign of a methodological artifact. If I had to consume 20% of calories as casein I would also get sick even without aflatoxins.

Stan (Heretic)

[Heretic]

... Dr. Campbell discusses the fact that exposure to hepatitis b virus leads to liver cancer only in the presence of animal protein.

Could you please post the reference? Thanks.

[hope101]

... Dr. Campbell discusses the fact that exposure to hepatitis b virus leads to liver cancer only in the presence of animal protein.

Could you please post the reference? Thanks.

Actually, I'll go you one better. For only the amazing, low price of $11.53, you too, can own a copy of "The China Study". I would urge you to invest. It might just save your life.

http://www.amazon.com/China-Study-Compr ... 380&sr=8-1

[xetaprime]

What about Goat Milk?

[TanneryGulch]

Heretic, the studies she refers to are the two Hu/Cheng ones you already discussed.

20% casein is a lot -- a diet of nothing but whole milk would be 17% -- but assuming Campbell's generalization from casein to animal protein holds, then this is hardly a case of "too much of anything, even water," since 20% total animal protein is within the range actually being eaten by many people in the developed world, and there are diet gurus with huge followings (e.g. Sears) recommending even more.

In any case, can we at least lay to rest your claim that casein requires aflatoxin?

[Heretic]

Heretic, the studies she refers to are the two Hu/Cheng ones you already discussed.

20% casein is a lot -- a diet of nothing but whole milk would be 17% -- but assuming Campbell's generalization from casein to animal protein holds, then this is hardly a case of "too much of anything, even water," since 20% total animal protein is within the range actually being eaten by many people in the developed world, and there are diet gurus with huge followings (e.g. Sears) recommending even more.

In any case, can we at least lay to rest your claim that casein requires aflatoxin?

It may support the idea that huge amount of casein in a diet is not healthy (for rodents) even without aflatoxins, but I think my other objection does stand! Those particular studies DO NOT prove what Campbell and Karen may have stated that all animal protein is cancer promoting! Campbell's generalization from casein to all animal protein is precisely the aspect that I think is totally unsupported! Also I am getting slightly suspicious whenever animal versus plant aspect comes in discussion, and someone uses Dr. T.C. Campbell's work for support. Please bring someone else...

I believe that he made several deduction mistakes based on unwarranted generalizations:

1) casein --> all animal protein

2) rodents --> humans

3) monodiet consisting of casein and sugar --> general human diet

4) increased risk from 20% casein isolate diet --> presumed risk with a much lower human consumption of casein from real food

Stan (Heretic)

---------------------

"It's hard to free fools from the chains they revere" ~Voltaire

[Yoga Nurse]

... Dr. Campbell discusses the fact that exposure to hepatitis b virus leads to liver cancer only in the presence of animal protein.

Could you please post the reference? Thanks.

Actually, I'll go you one better. For only the amazing, low price of $11.53, you too, can own a copy of "The China Study". I would urge you to invest. It might just save your life.

http://www.amazon.com/China-Study-Compr ... 380&sr=8-1

Thanks Hope.

Anna

[momof4]

How about the library? I get tired of people saying they can't read a book that's recommended here because they'd have to pay for it. The China Study and Dr McDougall's books are available here, in the pork capital of world, so they're likely available all over the country.