The short answer
The China Study, by T. Colin Campbell and Thomas M. Campbell II, argues that animal protein, particularly casein, drives cancer and chronic disease. This page explains why observational diet data cannot prove that, using NCI's own cautions.
The book draws on a large observational survey of diet and disease in China plus animal laboratory work on casein. This page did not verify details of the survey.
The book was published in 2005. This page did not verify its sales figures.
Observational studies can show associations between diet and disease rates across populations, but cannot on their own prove that one dietary factor causes cancer in an individual.
NCI says studies of human populations have not yet shown definitively that any dietary component causes or protects against cancer, with few exceptions.
On this page
About this book
- Author:
- T. Colin Campbell and Thomas M. Campbell II
- First published:
- 2005
- Publisher:
- BenBella Books
- Type:
- Popular science
- Pages:
- 417
- Cancer covered:
- Not diagnosis-specific; a general argument about diet, particularly animal protein, and chronic disease including cancer, drawn from a large observational nutrition survey.
This page describes a published book for education. We have no financial relationship with any author or publisher and earn nothing if you buy it. A book — including one written by a doctor — is not medical advice, and one person’s experience is not a guide to your own care.
Choose how you want to read this
The whole article, with every detail and caution.
What the book is
The China Study was written by T. Colin Campbell and Thomas M. Campbell II. It was published in 2005. It argues that animal protein, and casein in particular, promotes cancer and other chronic disease. It also argues that a whole-food, plant-based diet can prevent or even reverse them.
The book draws on a large observational survey of diet and disease in China and on laboratory work with casein in animals. This page did not verify details of that survey, the authors' careers or the book's sales, because no approved source covers them. What follows sticks to what NCI says about diet evidence.
What NCI says about diet evidence
NCI's diet page draws a clear line between association and cause. When a dietary component is linked to cancer risk, it means the two are associated. It does not mean the food is responsible for, or causes, the change in risk. People in a study can differ in many ways besides diet.
NCI also says studies of human populations have not yet shown definitively that any dietary component causes or protects against cancer, with few exceptions. It gives an example. Compounds in cruciferous vegetables have shown anticancer effects in cells and animals, but human results have been less clear.
Where to read the book carefully
Comparing diet and disease across regions can point to ideas worth testing. It cannot show that one food causes one disease. Regions that differ in diet also differ in many other ways, and any of those can affect cancer rates.
The casein research was done in animals. Findings in animals do not always hold in people. NCI's own example of cruciferous vegetables shows the same gap between cell and animal results and human results.
A strong claim about cancer usually needs more than one dataset or one lab finding. Look for results that hold up across several well-designed studies. Look for clear wording about the difference between association and cause. A single named dietary villain makes a simple story, but the evidence is usually messier.
If you are thinking about a big diet change
During treatment, NCI says to talk with the doctor in charge of your treatment about the foods you should be eating, because your nutrition needs are individual. Ask about a registered dietitian before you drop a whole food group. Ask what supplements, if any, you would need.
For the broader picture, see diet and cancer risk. Another single-factor diet claim gets the same treatment here. See can keto or carnivore diets prevent cancer.
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Sources
This page discusses The China Study for education. It is not medical advice, and nothing here is a judgement of anyone's real medical care.
Common questions
What kind of evidence is behind the book?
Observational data on diet and disease, plus animal laboratory work on casein. NCI says observational studies show associations, not that a food causes a change in cancer risk.
What is the book's central claim?
That animal protein, and casein specifically, promotes the growth of cancer and other chronic diseases, and that a whole-food, plant-based diet can prevent or in some cases reverse them. The book draws on observational survey data and earlier animal research on casein.
Has the book's central claim been scientifically validated?
Not to the degree the book asserts. Observational data shows associations, not proven causation. NCI says human population studies have not yet shown definitively that any dietary component causes or protects against cancer, with few exceptions.
Does NCI recommend avoiding animal protein to prevent cancer?
This page did not find an NCI statement telling people to avoid animal protein to prevent cancer. NCI's diet page says the evidence on individual foods is not definitive. Ask your team or a dietitian about your own needs.
Is a whole-food, plant-based diet bad for cancer risk?
This page does not claim that. The caution is about the book's strong causal claims on animal protein and casein. During treatment, NCI says to talk with the doctor in charge of your treatment about the foods you should be eating.
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Written by: Cancer ExplainedSources last checked: 2026-10-02 what this meansLast updated: 2026-09-03Next planned review: 2028-09-03
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Cancer Explained does not originate medical claims. Every page restates guidance already published by the National Cancer Institute, the CDC, the USPSTF and the FDA, in plain language, with the source cited so you can check the original yourself. AI does the translating and organizing; automated checks test claims, citations, clarity and safety before anything publishes, and this is translation and navigation, not clinical judgment. Nothing here is personal medical advice, and no page can account for your particular situation.
Editorial status: Source checked — This page was written with AI assistance and then compared with the sources listed on it, looking for statements those sources do not back up. That check is not a sentence-by-sentence record and can miss errors. It is not a medical review, and it does not confirm the page is complete or right for your situation.
Human medical review: not completed. Pages here are not signed off by a clinician before they publish. That is not an oversight we are quietly working around: we restate published guidance and cite it, so the authority belongs to the source rather than to us, and every page names where its claims come from — you can verify us instead of trusting us. Where a volunteer clinician has reviewed a page, their name and credentials appear on it; where no name appears, no clinician has checked it. We are glad to have reviewers and are recruiting them, and we do not hold pages back waiting for one. Use this site to understand your situation and to ask better questions of the people treating you.
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