The China Study – Part 1

The China Study was a popular book written by a physiologist T. Collin Campbell.  The book sold tens of thousands of copies, and is commonly cited by vegetarians as scientific basis for their diet.  Campbell himself is a vegetarian, or as he likes to call himself, “a whole plant eater.”

Campbell didn’t start out as a vegetarian, he grew up on a farm, and spent the first few years of his career thinking that the farm diet was the healthy way for a person to live.  On the basis of his early work with some proteins and cancer, and some statistical work he did from rural China villages he wrote The China Study. In it he formed the conclusion that an animal based diet is the promoter for cancer, and that if people converted to a whole plant diet (not processed flours, pastas, or processed, white, rice ) they would lose weight, have less cancer, less heart disease, and less obesity.

To be fair, let me quote him:
“In fact, dietary protein proved to be so powerful in its effect that we could turn on and turn off cancer growth simply by changing the level consumed.” (page 6-7)

The premise for much of this comes from a Campbell’s work with aflatoxin – a potent carcinogen that is found in peanuts. Campbell’s work noted that with adding a milk protein casein – there was a direct relationship to the extent that rats appeared to get foci of cancer.  Campbell then extrapolates that data from a milk bio-active protein to all animal proteins.

“..People who ate the most animal-based foods got the most chronic disease.  Even relatively small intakes of animal-based food were associated with adverse effects. People who ate the most plant-based foods were the healthiest and tended to avoid chronic disease.”

His first declaration came from his lab studies where he examined the biologic influence of a milk protein (casein, which is a bio-active protein) on rats who were fed a potent carcinogen. The rats that were given more of this milk protein developed more foci of liver cancers.

Casein makes up 20-45% of the protein in human milk.  Does this mean that mother’s should not breast feed their children? That we should not be drinking milk at all? Does this mean that all animal based proteins are cancer causing, and the reason we develop cancers?

The answer to all the above questions are NO.  Simple experiments done with rats do not form universal answers to major health questions, nor do they provide us with scientific insight into the health of human beings.

First, let’s look at proteins. Proteins are called the building blocks of tissues.  They are complex molecules that contain a number of amino-acids.  Amino acids are divided into two types: essential and non-essential amino acids.  Essential amino acids are those amino acids that humans cannot make, and thus we must get them from our diet.  When you eat protein, the digestive process breaks down the proteins into the various amino acids which are then carted away by the blood stream and used to build or rebuild cells in your body.  That is the simple stuff. Proteins are found in animals and plants.  Once the protein is digested, and the amino acids are freed, your body has no idea if that amino acid came from a bean or a T-bone steak. The lysine (an essential amino acid) your body gets from a T-bone steak looks no different than the lysine your body gets from a soy bean or a walnut.

Proteins can have more of an effect than just being used as a source for amino acids. The way proteins are put together they look less like pearls on a string (amino acids being the pearls) and more like rather complex geometric shapes.  Some of those shapes can unlock powerful changes in a person. Allergies, for example, come from proteins that turn on an overwhelming inflammatory response in people who are sensitive to them.  Take that same protein and alter its structure so that the 3D structure of the protein is altered (this can be done by changing a single amino acid, or heating a protein, or putting the protein in a acid environment) – and that protein won’t cause the same reaction.

Proteins are quite complex – just to give you an example, here is a representation of what some people think the protein ovalbumin looks like (this is the protein found in egg whites):

A 3-D look at ovalbumin, the protein found in egg whites

One of my favorite proteins because almost 30 years ago we used some genetic modification of this protein expression in a virus, but that is another story.

Proteins are complicated 3-D structures, and like keys into locks, if you change a bit of their structure they no longer unlock the reaction.  Some proteins cause other reactions in people besides the allergic reaction — but anyone can be allergic to almost any protein, except most people are not allergic to proteins their own body makes – except in some severe auto-immune disorders (arthritis, Lupus).

Other keys that proteins unlock can be hormonal.  Insulin is a protein – it is made up of a chain of amino acids and looks like this:

The primary structure of insulin – each amino acid in sequence

Insulin’s is a protein, that if given in the blood stream will unlock cells and force glucose into cells. Without insulin blood sugar rises, people can go into coma, and long standing low insulin levels can cause all the complications of diabetes. But insulin is a bio-active protein.

But if you eat insulin, when the insulin is in the stomach, the acid of the stomach will quickly change the structure of the insulin, it will break down, and ultimately not be a bio-active protein, but instead become just a source of amino acids for the body to use.

Back to Casein- which isn’t a single protein, but a group of proteins found  in milk.  In Campbell’s work he gave rats that had been subjected to a cancer causing agent high doses of casein. He then examined their liver for foci of pre-cancer lesions, and noted they were higher with the higher levels of the milk protein.  From that he determined that depending on the level of protein, its possible to turn cancer genes on or off. This becomes a later theme of the book. Increased levels of animal proteins cause human disease from heart to cancer, and here is some experimental evidence to prove it.

Casein is a bio-active protein- which is not surprising. If you want mammals to grow you want to give them proteins that will not only break down to supply nutrition, but will also serve to promote growth of those cells. One could conclude that if you have a cell that has been treated with a carcinogen that adding something that makes it grow will increase its growth.

A non-casein example is hormones and prostate cancer, for which Charles B Huggins received the Nobel prize in 1966. Huggins found a number of cancer cells were turned on and off by hormones.  Estrogens are not proteins, they are another class of chemical compounds – but the idea that a chemical compound could signal and cause growth in cancer cells was well established with Campbell did his work with rats.

Back to the questions: Casein does not appear to have a role in any human carcinogensis. In fact, those milk proteins do appear to have a protective effect against cancer in humans. Campbell’s work with rats has not been reproduced to find the reason he saw what he saw at that time.  Whether the test he used to predict cancer, and the proteins he fed those rats exposed to that carcinogen apply to humans in any way is more than any speculation.

Milk is more than casein proteins, there are also whey proteins- which have also been found to have an effect with cancer, a protective effect.

It is not the first time that someone doing bench research takes their ideas from the laboratory bench and applies them globally.  It is what we are supposed to do.  We are supposed to see the large picture. In this case, Campbell’s conclusion was that animal protein induced cancer, which did not happen with plant protein.

For part one of The China Study- while he reports years of his research as a basis for his beliefs, it does not hold up for all animal proteins. Animal proteins for the most part are broken down and serve as sources of amino acids and nutrition. Milk is an essential part of all mammal diets for their young . The world of research has gone beyond Dr. Campbell’s bench days, and is now looking at pathways of cell cycles within pathways, and nowhere to be found is the broad picture that plants are better than animals.

Many of the hypothesis that were generated in the laboratory I worked in no longer apply either. Some have, but research has become more and more focused on other pathways, with new pictures.

Bernard Roizman, my science mentor- where I spent many wonderful years in his lab

Still, for those who read The China Study, and wonder if milk is bad for you, or your baby, or if this is the simple model for cancer and turning off cancer genes — it is not.

In a future article on the China Study, we will focus on how they conducted the epidemiological research in China.  We will take a unique perspective on it, we’ll take it from China itself, to see the pros and cons of how the rural village research and death statistics worked.

Dr. Terry Simpson About Dr. Terry Simpson
Dr. Terry Simpson received his undergraduate and graduate degrees from the University of Chicago where he spent several years in the Kovler Viral Oncology laboratories doing genetic engineering. He found he liked people more than petri dishes, and went to medical school. Dr. Simpson, a weight loss surgeon is an advocate of culinary medicine. The first surgeon to become certified in Culinary Medicine, he believes teaching people to improve their health through their food and in their kitchen. On the other side of the world, he has been a leading advocate of changing health care to make it more "relationship based," and his efforts awarded his team the Malcolm Baldrige award for healthcare in 2011 for the NUKA system of care in Alaska and in 2013 Dr Simpson won the National Indian Health Board Area Impact Award. A frequent contributor to media outlets discussing health related topics and advances in medicine, he is also a proud dad, husband, author, cook, and surgeon “in that order.” For media inquiries, please visit

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Latest Comments

  1. Anonymous says:

    You are an idiot. You provide nothing at all that either correctly represents Campbell’s work or any repudiation of it. You are an idiot.

  2. thedoc says:

    The post is not meant to repudiate or endorse his work- but provide a perspective of a physician (which he is not) and a scientist who also has worked in the field of cancer research – more of the molecular level. Sorry if you think a single post could do more than a part of his work. But having just returned from China, we will post more about his work from the project, and updated the results.

  3. Ben Morton says:

    You obviously have not seen “Forks Over Knives” which supports the “China Study” or other supporting evidence which support this body of information. You have your own ax to grind, but this is what I would expect from someone of your background. Your views are meaningless.

  4. The Doc says:

    I have -and will indeed have a response to that movie. No ax to grind – we just report science here. And a movie, by the way, is not what we use as evidence of anything. Forks Over Knives has a point of view- some of which is science, much of which is opinion – and having been to China- well, there are a few issues with his project. All to come in good time.

  5. Kate says:

    I just saw the movie and wanted to try isogenix products so I googled casein (one of the products ingredients) and your site came up….now I am thoroughly confused. Is it bad, or not, to take milk products?? They are part of the ingredient list on this program and I ‘m not sure whether to do it now or not…..

  6. thedoc says:

    The early work that Campbell did was never reproduced, and was very isolated as to cause. It is not bad to take milk products

  7. chuck taylor says:

    The china Study has gotten my attention, but I’ve felt that there was need to to not take its claims for granted and to search for rebuttals. I’m not a scientist, doctor, or nutritionist, but a retired electrical engineer. After reading your comments, Denise Munger’s and some others, we have the good news bad news.
    Bad news: the china study is not entirely the answer to our health problems.
    Good news: We don’t have to go vegan, which is very, very difficult in our society.
    From all that I’ve read, I have some questions:
    1. Is cancer all about DNA? Our DNA gets messed up, then the DNA copies it self before the the messed up parts get repaired, then we have cancer?
    2. Is heart, pulmonary, cardiovascular problems also related to DNA issues like in No.1 above.
    3. How effective are anti-oxidants and free radicals in DNA repair and destruction.
    4. Finally, is T. Collin Campbell’s model for cancer developmental phases “initiation, promotion, and progression” correct? Is that a known and accepted analysis by all scientist, doctors, researchers knowledgeable in the development of cancer?
    thank you,

  8. thedoc says:

    Cancer is all about DNA – it is the cell program. It is either prone to be a problem (inherited disorders), or changed by things- such as radiation, certain chemicals. The idea of initiation, promotion, and progression were great ideas – for the 1970’s. It still has some application today – but for the most part this is being replaced. The old model (not Campbell’s by the way) – you have a cell that has altered DNA. Then you force the cell to divide more, and it takes off in an uncontrolled manner — example: some breast cancers with estrogen. Alcohol does not cause DNA damage, for example, but it appears to promote the cell.
    Most of the time when the DNA is messed up, the cell simply dies.
    Lets talk heart- another large topic, but most of the time people want to talk about the coronary arteries and what causes them to become progressively occluded with plaque. Part of that is DNA- if you have hyperlipidemia or hypercholesterolemia, then you are prone to that. If your arteries have a certain anatomy (the way they bend, the amount of collateral blood flow, the size of them) they can be more prone to disease. Part of it is doing damage- smoking for example can cause damage to the arteries.
    How effective are anti oxidants- zip. See my post about them here.

  9. Christine says:

    Caldwell B. Esselstyn, Jr., M.D.
    A groundbreaking program backed by the irrefutable results from Dr. Esselstyn’s 20-year study proving changes in diet and nutrition can actually cure heart disease.

    Dr. Esselstyn, Jr., M.D. is a former internationally known surgeon, researcher and clinician at the Cleveland Clinic, explains in this book it can be prevented, reversed, and even abolished. Dr. Esselstyn argues that conventional cardiology has failed patients by developing treatments that focus only on the symptoms of heart disease, not the cause.

    HE IS ALSO PLANT STRONG…and agrees with The China Study
    In fact finding keep in mind these men in are not entirely wrong. To reverse heart disease without surgery and with a clean diet is super impressive and much less radical than surgery.
    Check out his work… step up and stop siding with the dairy industry. O and comparing mothers milk to 1,000 pound cows…Really? We drink more milk in the US than any other country and still we lead the world in arthritis….

  10. thedoc says:

    First, Esselstyn isn’t a cardiologist, he is a retired surgeon, and his field was not nutrition or cardiology, but breast cancer. It would be nice if heart disease could be reversed but look at his data: (a) Small numbers of highly select people — too small to be significant. (b) Not reproduced in any appreciable way by anyone.

    Second, The China study was so flawed, no one seriously uses it for anything other than how population studies should not be done. See our article about it.

    Third, do I side with the dairy industry? Where on earth do you get that? Do I say drink more milk? Do I advocate that at all?

    So yes- if you can reverse heart disease – great.
    By the way– my father- major heart attack 30 years ago, age 55 — eats lots of meat, fish, dairy, coffee, and ice cream — he is alive and well at 88 years old. That is the equivalent of one of Esselstyn’s 11 patients. Maybe I should write a paper

  11. Kro says:

    You would think a doctor would be more specific with their answers. Even you truly believe that that milk products do not contribute to cancer growth, you should not make general statements like “It is not bad to take milk products”. What about cholesterol, fat, and proteins that cause high acidity in blood?

  12. Kro says:

    Everyone who disputes Esselstyn’s studies or even Gerson therapy always state a similar argument “The selection was cherry picked and too small to be significant.” Surely there is enough support an evidence by now for some large public institute to fund a much larger study. Why hasn’t this been done? Are they afraid that a larger study will support the findings presented by Gerson and Esselstyn and all the others?

  13. thedoc says:

    Really- we recommend mother’s breast feed their children. There is no increase in cholesterol in patients that drink milk – zero, none. In terms of proteins that cause “high acidity” – that is rubbish. The body pH is well regulated and proteins are not absorbed directly into the blood stream but are broken down in the small bowel to amino acids then transported across. The body cannot tell if the amino acid lysine came from a plant or a horse.

  14. thedoc says:

    We just had a large study with 500,000 individuals in Europe that showed that meat did not cause an increase in mortality. Gerson has no studies showing its data – you can see that in a later post. No one is “afraid” of Gerson and Esselstyn. The reason we say they were cherry-picked is because they were. But there was not evidence that this in any study, of any diet, of any significance anywhere. By the way- in The China Study, when those “remote” areas are looked at with modern medicine, they have heart disease- but when he did the study it simply wasn’t reported

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