I have been asked to respond to Dr. Joseph Mercola’s views on The China Study.^[1] I do not wish to demean his motivations, enthusiasm, sincerity, or beliefs; however, readers unfamiliar with Mercola may find this context helpful: Mercola is an osteopathic doctor, author, and businessman best known for founding Mercola.com in 1997. One of the most trafficked health websites on the internet, Mercola.com is described “as a portal for up-to-date natural health information and resources that can help readers and subscribers adopt better lifestyles and achieve optimal health.” It is also frequently criticized for employing dubious and aggressive marketing tactics, proliferating numerous unfounded opinions on nutrition and health, and spreading pseudoscientific misinformation, as illustrated by the multiple warnings the FDA has sent to Mercola.com LLC for its false or misleading claims.^[2][3][4]

Mercola’s comments on The China Study betray such a lack of understanding of what is written in the book that I wonder whether he read it. The book The China Study, which he describes as pro-vegetarian and vegan (terms I consistently and deliberately avoid), contains 18 chapters; only one chapter is devoted to the project undertaken in collaboration with the Chinese Academy of Preventive Medicine and Oxford University in the early 80s. Mercola’s critique focuses only on this study while neglecting the context provided by the rest of the book, including the decades of published peer-reviewed research on cancer establishing biological plausibility and the findings of numerous physician colleagues (Drs. Dean Ornish, Caldwell Esselstyn, John McDougall, etc.).

Moreover, even Mercola’s assessment of the China Project widely misses the mark. Correlations, he observes, do not prove causation. This is elementary. He might be surprised to learn that neither the 894-page monograph of the China Project nor The China Study suggests that correlations prove causation. I have written about this elsewhere:

“The main value of the China data set is its descriptive nature, thus providing a baseline against which other data sets can be broadly compared, either over time or over geographic space. I must emphasize: the correlations published in our monograph CANNOT be blindly used to infer causality—at least for specific cause-effect associations having no biological plausibility. Nonetheless, they do offer a rich trove of opportunities to generate interesting hypotheses, relatively few of which have been explored to date. In contrast, using models representing biological plausibility, which was determined from prior research, I simply wanted to see if they were consistent with the China survey data.”

The rest of Mercola’s commentary includes anecdotes, speculation about the effects of pasteurization, and a brief description of his nutritional typing program.^[1] This nutritional typing hypothesis, categorizing individuals into different groups, is based on the idea that “we are all uniquely designed and require customized plans.” The model is excellent for growing a customer base, but he provides no convincing evidence to substantiate the claim. In fact, he provides no peer-reviewed scientific research at all in his critique of The China Study.

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On animal protein, he makes an unconvincing case for distinguishing between the nutritional profiles of raw and pasteurized dairy. His views on this subject closely parallel the stance of the Weston A. Price Foundation (WAPF), a Washington-based organization known for its extensive lobbying efforts, including its quasi-evangelical campaigns against soy and pasteurization.^[5] The organization ostensibly relies heavily on a personal survey of dentist Weston Price, who, in the 1920s and 30s, visited 14 Indigenous peoples in various parts of the world to examine and photograph their dental health (dental caries and dental arch formation). However, the foundation bearing his name has gone far beyond his work. They would have us believe that Price published extensive data to support the health value of cow milk and high-cholesterol animal-based food and that he discovered a fat-soluble factor in milk that is likely responsible for the healthy effects of cow milk. My view, having read Price’s book, is that he did not accumulate, tabulate, or interpret sufficient data to support this view.

Although I question the value of responding to people whose professional views are aligned with compromising commercial interests and who have little if any professional experience in peer-reviewed original research, I must address the Mercola (and WAPF) claim that the adverse effects of animal protein—whether shown in my or other research—are a consequence of pasteurization, homogenization, hormones, pesticides, or something else.

Although pasteurization and homogenization may cause slight changes in the physical characteristics of proteins, I know of no evidence that amino acid contents are altered by these treatments. This is important because many studies throughout the recent decades have shown that amino acid contents—not pasteurization, homogenization, or chemical contamination—determine biological effects. For instance, the nutritional response caused by plant-based proteins can be experimentally changed by shifting its amino acid profile to mimic animal-based proteins. We discovered this in our lab when we experimentally altered the level of the amino acid lysine in wheat protein and observed it behave just like casein, a powerful promoter of experimental cancer.^[6] Countless studies going back many decades have shown a similar effect of animal- and plant-based proteins on body growth and other events associated with body growth—all because of differences in amino acid compositions.

I should also mention that my experimental research proceeded beyond the singular effects of animal protein. Throughout the years (all our research was supported by NIH funding and documented in several hundred publications in well-known professional journals), my thinking and research have included experimental studies on other nutrients, mechanisms, and health or disease outcomes. Moreover, the casein used in our extensive laboratory experiments was before hormones and factory farming were the norm; therefore, it most likely represented the effects one would expect from grass-fed animals. Its effects cannot be attributed to pasteurization or any other process commonly blamed by the WAPF.

It might seem reasonable to assume that grass-fed animal products are healthier than similar products from a concentrated animal feeding operation (CAFO), perhaps due to slightly healthier fatty acid composition and a minimal level of tissue antioxidants derived from the plants consumed by grass-fed animals—but they do not come close to the health value of plant-based alternatives. Even if there were a slight advantage to choosing organic grass-fed animal products, there is not enough land, water, or other resources necessary to meet the demand for such products. Because this argument is clear to anyone who has given it any thought, I have often wondered about the motivations of those who promote grass-fed animal agriculture. Almost uniformly, whenever I have looked a little more closely, I have found either commercially compromised interests or a personal reluctance to find fault with animal-based diets.

References

1. Mercola J. The dark side of The China Study story supporting vegetarianism… Mercola.com. September 8, 2010. https://articles.mercola.com/sites/articles/archive/2010/09/08/china-study.aspx
2. Gumpert DE. Old-time sales tricks on the net. Business Week. May 23, 2006. https://web.archive.org/web/20090706135749/http://www.businessweek.com/smallbiz/content/may2006/sb20060523_063274.htm
3. Thompson G. FDA warns doctor: Stop touting camera as disease screeing tool. Chicago Tribune. August 19, 2019. https://www.chicagotribune.com/2011/04/26/fda-warns-doctor-stop-touting-camera-as-disease-screening-tool-2/
4. U.S. Food and Drug Administration (FDA). Warning Letter: Mercola.com, LLC. February 18, 2021. https://www.fda.gov/inspections-compliance-enforcement-and-criminal-investigations/warning-letters/mercolacom-llc-607133-02182021
5. The Weston A. Price Foundation. Home page accessed July 1, 2024. https://www.westonaprice.org
6. Schulsinger, D. A., Root, M. M., & Campbell, T. C. Effect of dietary protein quality on development of aflatoxin B1-induced hepatic preneoplastic lesions. J. Natl. Cancer Inst. 81, 1241–1245 (1989).