T. Colin Campbell’s The China Study Reviewed

Campbell, T. Colin, The China Study; Startling Implications for Diet, Weight Loss and Long-term Health. Dallas, Texas: BenBella Books, 2006.

I recently finished reading the China Study: Startling Implications for Diet, Weight Loss and Long-term Health by Dr. T. Colin Campbell and his son Dr. Tom Campbell. I have been intrigued with the book for quite some time, however for some reason the 400 page monograph seemed daunting. While still 400 pages, the book is a distilled and truncated version of Dr. Campbell’s and Dr. Chen Junshi’s Diet, Life-style and Mortality in China which clocks in at a massive 894 pages. The New York Times called this study the “Grand Prix of epidemiology" and the "most comprehensive large study ever undertaken of the relationship between diet and the risk of developing disease."

This book is a powerhouse of fair, balanced, and evidenced-based nutritional information, which makes the book standout when it is placed among “diet” books on shelves in bookstores. Containing nearly thirty pages of references and three appendixes with more detailed information, the book is clearly the result of a lifetime (over forty years in Campbell’s case) of research in nutrition.

Background:

T. Colin Campbell’s story is interesting on its own and he includes a large part of his story in the final section of the book. He grew up on a rural dairy farm. Perhaps ironically, his father died quite young of heart disease. As the first in his family to attend college, Campbell studied pre-veterinary medicine at Pennsylvania State University. He obtained his B.S. in 1956 and then attended veterinary school at the University of Georgia for a year. During that time he became increasingly interested in the diets of humans, changed tracts, transferred to Cornell,  and finished his Ph.D. under Clive McCay (a famous researcher of diet and aging) in 1961. He then went to teach and research at MIT and later Virginia Tech, but ultimately spent the majority of his career in the nutrition sciences department of his alma mater, Cornell.

His early research focused on malnutrition and protein, which brought him to Indonesia, to study diet and lifestyle. While there he began to notice, that contrary to his then working hypothesis, the more animal foods one ate, the more likely the person would suffer from cancer. Up to this point, Campbell firmly believed malnutrition was the result of a lack of animal protein from a persons diet. However he soon began to question this hypothesis and the result dramatically altered his career. Finally, while he was in Indonesia, Campbell read a small and obscure paper published on cancer and animal protein in mice and rats, which observed that cancer grew more rapidly when a diet contained higher levels of casein (the main protein found in cheese and dairy products). Even more important, a diet low in animal protein could stop and even reverse the growth of cancer cells.

Campbell returned to the States and recreated the experiment he read about. It amazed him. He then spent the next thirty-five years furthering the field along this path while winning some of the most prestigious awards for research along the way. However, his most remarkable work remains the China Study.

The Study

In the early 1970s, the premier of China was diagnosed with terminal cancer. As a result, he ordered a nationwide survey to collect information on the disease and its impact on the Chinese population. Between 1973-75, the surveys were collected. It was a monumental study of death rates for twelve different kinds of cancer for more than 2,400 Chinese counties and 880 million (96%) of their citizens. The end result was an atlas showing where certain types of cancer were high and where they were almost nonexistent. The atlas made it clear that in China, cancer was geographically localized. “Some cancers were much more common in some places than in others.” This was significant because the variations existed within a country where 87% of the population was of the same ethnic group, essentially taking genes out of the equation of cancer risk. Because there was such a massive variation in cancer rates among different counties where genetic backgrounds were similar from place to place, it seemed possible that cancer could be connected to environmental and lifestyle factors rather than genetics (it is estimated that genetics determines only around 2-3% of the total cancer risk- “Genes do not act in isolation; they need a trigger for their effects to be produced”).

China proved the perfect place to study cancer and lifestyle because “critical to the importance of the China Study was the nature of the diet consumed in rural China.” It was a rare opportunity to study health-related effects of a mostly plant-based diet.

This sparked Dr. Campbell’s interest and in 1983 an international team of biochemists and scientists were working closely to find correlations between the cancer atlas and a new, large collection of dietary surveys and blood work. Between 1983-4, they collected data on 367 variables from 6,500 people living in 65 different counties, and then compared each variable with every other variable. The results were astonishing. They collected over 8,000 statistically significant associations between lifestyle, diet and disease variables. Not surprisingly, the more animal protein that was consumed, the greater the risk for contracting a number of different diseases, including several different types of cancer, heart disease and diabetes. They also compared Chinese populations to American populations of similar activity levels and found that on average the Chinese consumed 30% more calories based off body weight than Americans and yet found their body weight was on average 20% lower.

While Dr. Campbell is very forthright about the fact that “absolute” proof of causation is almost impossible in scientific studies, his book leaves little doubt about the correlation between diet and disease. The study emphasized a whole-food plant based diet while also eliminating all meats, poultry, fish, eggs and dairy products (Dr. Campbell identifies dairy as one of the most potent carcinogens that humans are exposed to). They claim that eating a healthy vegan diet will help one escape, reduce or even reverse the development of chronic disease.

The Actual Book

 In this work, Dr. Campbell has set an ambitious goal: “I propose to do nothing less than redefine what we think of as good nutrition.” The book is divided into four sections, but for simplicity it can really be divided into three parts.

The first section reviews some of the ground I’ve already covered. Dr. Campbell’s transition towards and advocacy for a plant based diet, his early work on mice, casein, and tumor growth and the China study. Just from this section alone, Campbell builds a compelling case linking the consumption of animal protein, cholesterol, and processed foods to increased cancer risks. However, in section two Campbell goes into a detailed review of the peer-reviewed secondary literature dating back to the late 1800s, which demonstrates how animal protein is linked to nearly every other major western disease (also know as diseases of affluence).

In this section, Dr. Campbell and his son have done extremely diligent work. Each chapter relates to a different major disease and how diet and nutrition can affect that disease. These chapters include heart disease with an extended discussion of the work from Dr. Esselstyn and Dr. John McDougall, obesity, diabetes as well as more surprising chapters on autoimmune diseases, bone health, and kidney, eye and brain diseases.

In each chapter, Campbell discusses the newest research on the causes of these diseases. By this point in the book, it is no surprise that animal products are intimately linked to each one. For instance, it now seems the autoimmune disease known as Type 1 diabetes, previously thought to be a genetic issue, could actually be triggered by exposing newborns to dairy milk (perhaps in infant formula) too early in their lives. In fact a study done in Chile found that children weaned too early onto cow’s milk-based formula had a 13.1 times greater risk of contracting the disease. This is because most newborns are unable to fully digest the small amino acid chains or fragments of the original protein found in milk and remain in the intestines and absorbed into the blood. The immune system recognizes these fragments as foreign invaders and goes about destroying them. Unfortunately, some of these fragments look exactly the same as the cells of the pancreas which makes insulin. As a result, the immune system will also start attacking the cells of the pancreas and the body will no long be able to produce insulin. The result is a devastating disease that the child will have to deal with for the remainder of its life.

The final section focuses on why this information isn’t more common spread. The answer is surprising obvious. Imagine for a second a newspaper headline about Cows milk causing Type 1 diabetes? It would have a dramatic financial implication for American agriculture. Obviously the entire food system would be greatly impacted. As a result there a barriers built into the system to help protect against that from happening. But is it a conspiracy? According to Dr. Campbell, no it is not. Rather, he claims it is simply the powerful work of a few people favoring the status quo over  sound science.

Unfortunately, part of the status quo means that the majority of nutritional information is filtered through three different levels. First are the scientists, many of whom have close ties to the food and drug industries as their departmental positions are funded in part by various corporations, the result, according to Campbell, are nutritionists become less interested in challenging a system which literally supports them. These scientists are also the most likely to be placed onto governmental committees as "experts" who are responsible for creating acceptable nutritional standards. 

Second is government. Perhaps the saddest of the trio, the government has consistently put economic issues and corporate interests in front of protecting their citizens’ health. This is evidenced every time a major governing body fills committees with lobbyists rather than scientists or when lobbyists are successful in their attempt to bury an honest report. Just think back to the most recent farm bill debate where tomato sauce ontop of pizza was defined as a vegetable and pink slime was found to be nutritionally acceptable. 

Finally, Campbell points his wagging finger at the corporations who fund most of the nations nutritional research. These corporations are broad in their range as well as their influence. Obviously, the meat, dairy and egg industries are powerful, but Campbell also reminds his readers that the orange industry has been startlingly successful at identifying their product with Vitamin C. Not only that, but drug companies sponsor most medical schools in the nation. 

One does not need to have an overactive imagination to imagine what this trio has caused to those who eat the Standard American Diet. Campbell claims this is one of the largest threats to America's future security as a nation, as healthcare spending dwarfs even the swollen military budgets yet the population becomes increasingly less healthy. Campbell’s theory is more than plausible as he details his own personal struggles from within the scientific community. Indeed it is often hard to believe his career was not squashed by these powers while he was still in Indonesia.

The book details the struggles that Dr. Caldwell Esselstyn and Dr. John McDougall  faced as well. Dr. McDougall was threatened with expulsion from his residency when he counseled a heart patient with advice about nutrition.  Dr. Esselstyn, a top surgen at the Cleveland Clinic, was ostracized by his peers and his plea to help Cleveland’s medical school develop a plant-based healing center have consistently been ignored. Still both have remain steadfast and have been able to help thousands of people heal themselves of heart disease and diabetes through diet.

It seems possible that some of Campbell’s claims are the result of overreaching from the actual evidence; after all, correlations are not causation. But its more likely that Campbell’s work is really that definitive. Campbell prides himself on the fact that he is nothing if not a careful and cautious scientist and while his book is written for a general audience, in the three appendixes Campbell goes into further detail about his protein studies in rats, his China Study, supplementations and Vitamin D – all of which were highly provocative as well as useful. When one considers the large amount of supporting secondary research Dr. Campbell relies on, it becomes nearly impossible to ignore his findings.

While the book has had it’s fair share of critics (many of which have been responded to personally by Campbell), it has met the praise of some of the most serious researchers in the field including Dr. Wilfred Niels Arnold from the University of Kansas and Professor Hal Harris of the University of Missouri–St. Louis who actually converted with his graduate students to a whole food, plant-based diet after reading the book. CNN’s Sunjay Gupta claims the book had a similar impact on him in his documentary called The Last Heart Attack. Campbell’s admirers also include President Bill Clinton, Oprah, Dr. Oz and thousands of others around the world. It seems to me that few others have had the impact on human health that Dr. Campbell has had (or, ironically, for animal rights, something Dr. Campbell does not vocally support). There are few books which can literally save your life, this is one of them and it should not be ignored.