Excerpt
The China Study Solution
Part 1
FOUNDATIONS OF HEALTH
Chapter 1
The China Study
"I think you mean the high-protein diet," she said. I looked back at her, a bit confused as to why my teacher would tell me I was wrong. I probably started to disagree. "I think you mean the rats that ate more protein ran more," she said again. "But that's okay. Thank you for telling us about the experiment." She turned to the class. "Class, thank Tom for the opportunity to learn about this experiment." That was probably the first nutritional disagreement of my life, and honestly, I had no idea what was going on.
I was in grade school, standing in front of the class giving a presentation. My dad, T. Colin Campbell, PhD, had long been a nutritional biochemist who, among other things, had been conducting cutting-edge research on the influence of diet on cancer at Cornell University. He had a robust research program that was gaining national recognition, and some of his research utilized rats eating different types of diets. He had offered my teacher the opportunity to conduct a little experiment in class involving rats. Nothing pleases elementary students more than having rodents in the classroom, so of course this seemed like a perfect idea.
The experiment explored the following question: If you fed rats different levels of protein, which rats would exercise the most? Each of the rats I brought in was housed in a cage with an exercise wheel that had a counter rigged up to register the number of times the rats turned the wheel. It was like a rat pedometer. The rats would intermittently get on the wheel and run and run and run--with purpose. It made me wonder if they knew they were not going anywhere, but I suppose you could ask the same thing at your local gym. Animals just need to exercise, I guess, even if it involves not actually going anywhere.
Both groups of rats ate exactly the same dietary chow with just one variation: One group had a low-protein chow (probably about 5 percent protein) and the other group had a high-protein chow (probably about 20 percent protein). The low-protein chow had a bit more sugar to replace the protein component.
I would feed the rats faithfully and record exactly how much they exercised. My dad supplied everything, of course. As you might imagine, as an elementary school student I didn't really know what was going on. I had some very cute rats and I wrote down the wheel counter results and I fed them. It was a good life.
After a week or two, I accumulated all of my data and got my final result: The low-protein rats exercised more. I was a compulsive child, relishing the details and double-checking all my records carefully. At the end of the experiment, I stood up in front of the class and reported the data to the other sniffly kids. The rats eating the low-protein diet ran more on their wheels, I said. This was when my teacher interjected, telling me I got either the rats or the numbers mixed up, that surely I meant that the rats eating the high-protein chow exercised more. As a young student, I had no idea why my teacher would disagree with my findings. She was a wonderful teacher--very caring, enthusiastic, and nurturing. She was one of my favorite teachers.
But I certainly did not get the numbers mixed up. She hadn't recorded the exercise wheel counts; I had. How would she know what the results were? I probably told her I was actually right, but I can't remember. I was also a stubborn child. It's funny--I can't remember much about the experience of the experiment, but for some reason I have remembered the teacher telling me I got things mixed up. And so went the first nutritional disagreement of my life. I didn't know it at the time, but this was my first lesson in the absolute reverence people have for protein.
GETTING TO KNOW DAD
Despite getting to play with rats in elementary school, I was not particularly enamored with my dad's work or with nutrition early in life. As a child and adolescent, I barely knew what he did for work. I was much more interested in sports and friends. Since that time, I have traveled a long, winding path to where I am today. In my nostalgia, it is hard not to think about some of the most remarkable experiences I have had since that time, particularly during my training as a medical doctor. I will never forget the life-and-death moments I have been privy to: doing chest compressions on a man who should have been in the prime of his life; doing chest compressions on a baby born at 26 weeks of gestation not even struggling to take in the first breath. I have been the person to tell someone that their mom was dying, or their spouse was dying, or that their imaging results showed a mass likely to be cancer. I have seen jubilant tears of joy and triumph and quiet love while helping to deliver almost 100 babies. I have assisted in the operating room at a variety of surgeries on patients made sterile by the patchwork of blue drapes around the surgical field. I will never forget some of these experiences. Nor will I forget the work, the stress, or the agony of uncertainty when nothing less than perfection is expected.
These moments may seem like they have nothing to do with nutrition, but the only reason I ever lived them was because of my experience in nutrition. I did not choose at an early age to become a doctor. Instead, it was a path I chose after working with my father and being inspired to pursue a career in health. After a childhood of not being aware of what type of work my dad did and later making forays into theater and acting, even immigration law, my path dramatically changed in my midtwenties. I had the opportunity to work with my dad as coauthor of The China Study: The Most Comprehensive Study of Nutrition Ever Conducted and the Startling Implications for Diet, Weight Loss and Long-Term Health, in which we tell the story of his career and the most exciting results in his research. In addition, we detail the findings of many dozens of other researchers investigating diet and health. In all of this, there is a surprisingly consistent, inspiring message: Whole-food, plant-based diets are profoundly important in preventing and even treating disease.
Much of my dad's work focused on protein and cancer. Having grown up on a dairy farm and gone on to school to find out how we might produce high- quality animal protein more efficiently, he started with the same reverence for protein that my grade school teacher had. But he went on to conduct decades of experimental research on diet and cancer using a variety of experimental rodent models. The research revealed that cancer caused by a dose of a potent cancer-causing chemical can be almost entirely controlled by protein intake. In fact, one of the most provocative experiments found that early cancer growth can be turned on or off simply by changing the level of protein consumed. And guess what? High-protein diets were the most dangerous kind. The figure below shows a 12-week experiment1 in which protein intake was changed every 3 weeks. It shows how diets composed of 5 percent protein turned off early cancer growth, whereas 20 percent protein diets promoted early cancer growth.
Perhaps the biggest surprise was that the protein that promoted cancer in these experimental models was casein, the main protein in cow's milk. Wheat2 and soy protein in their naturally occurring forms in food do not promote cancer, even at higher levels of intake. Furthermore, protein intake affects cancer initiation and promotion in numerous ways. Dietary composition did not exert its cancer-related effects through one enzyme or one chemical; instead, it changed just about every biochemical aspect of cancer initiation and promotion that was investigated. For decades, funding sources such as the National Institutes of Health, the American Cancer Society, and the American Institute for Cancer Research awarded my dad's research team highly competitive grant money, and the results of their work were published in prestigious peer-reviewed journals.
We also wrote about one of the most comprehensive studies of diet and disease ever undertaken--the China Project, for which we named our book. A survey of 6,500 adults in 65 counties in rural China, the study, called the "Grand Prix of epidemiology" in the New York Times,3 probed the relationships between 367 variables. The findings were clear: Even in a population that consumed only small amounts of animal foods, those who consumed more animal foods had higher cholesterol levels, which in turn were linked to higher rates of diseases more common in more affluent cultures, such as several types of cancers and diabetes.4
High And Low Protein Intake Effects On Early Cancer Growth
Early Cancer Mass
20% Protein Diet
5% Protein Diet
20% Protein Diet
5% Protein Diet
3 6 9 12
Time (weeks)
Source: Youngman LD and Campbell TC. The sustained development of preneoplastic lesions depends on high protein intake. Nutrition and Cancer 1992;18:131-142.
In the years I spent writing and conducting library research, I learned that the argument for plant-based diets had become much more powerful than any one person's research. No single study can "prove" anything, and determining what is likely to be true requires one to survey the depth and breadth of the evidence in favor of any argument. If you're unwilling to spend a couple of years looking for the dietary advice that meets those requirements of having a broad and deep evidence base, I will tell you now that the evidence overwhelmingly supports the argument that we should be eating more unrefined plant foods and less meat, dairy, and processed foods. No other dietary recommendation even comes close in terms of comprehensive support.
Consider heart disease: We have known for more than 50 years that populations consuming more animal foods have more heart disease.5 In fact, in many traditional plant-based cultures around the world, heart disease has historically been a very rare cause of premature death.6, 7 However, 21st-century America is quite different. How many people with heart disease do you know? Or high blood pressure? Or high cholesterol? Of course, in modern America, heart disease and its risk factors are everywhere. But even once heart disease is advanced, we know that making a change to a healthy lifestyle alone can reverse the disease. Both Dean Ornish, MD, and Caldwell Esselstyn Jr., MD, have reversed their patients' heart disease with diet and lifestyle, and proven it with angiograms (x-rays of the heart vessels). Dr. Ornish's Lifestyle Heart Trial was a randomized, controlled trial in which he put one group of heart-disease patients in a diet and lifestyle program, without cholesterol-lowering drugs, while the other group was given standard medical care. The standard medical care group received the usual medical recommendations (medications, testing, procedures, etc.) without the intensive lifestyle program. The lifestyle group was prescribed a diet rich in fruits, vegetables, and whole grains, with almost no meat or dairy foods and no added fat, along with stress-reduction techniques, exercise, and social support. What followed was nothing less than revolutionary: Despite a lifetime of bad habits having clogged up their arteries, those in the lifestyle group began to see disease reversal within a short period of time. The figure above shows how the blockages in the lifestyle group shrank while the blockages in the standard care group got bigger.8
Changes in artery blockages with dr. Ornish's lifestyle heart trial
Percent of artery blocked by average disease lesion (absolute change over 5 years)
+11.8%
Standard Care Group
Diet and Lifestyle Group
-3.1%
Source: Ornish D, Scherwitz LW, Billings JH, Gould L, et al. Intensive lifestyle changes for reversal of coronary heart disease. JAMA: The Journal of the American Medical Association 1998;280:2001-2007.
Diabetes is much the same story. Guess which populations have had the lowest rates of type 2 diabetes over the past 100 years? Those that eat high-carbohydrate, low-fat, plant-based diets.9 And we now know that, like heart disease, we can reverse diabetes. In a study published 30 years ago, 13 of 17 diabetic participants who had required daily insulin to control their blood sugar were able to come off insulin within just 3 weeks. Of 23 patients requiring oral medication, 21 were able to discontinue their medications within 3 1/2 weeks. When most people stop taking these blood sugar-lowering medications, their blood sugar level spikes upward. But participants in this program, even those who were stopping their medications, actually saw a decrease in their blood sugar. How did they do it? With a high-carbohydrate, high-fiber, low-fat diet, along with exercise10--the same diet plan that I present in this book.
Just take a moment and imagine that: If you are on medication for diabetes, within just 2 to 3 weeks of following the China Study Solution, you--with your doctor's okay--might be able to get off all your diabetes medication forever! (Remember, involving your doctor prior to making your dietary change is crucial.)
Then, of course, there is the weight loss. You can eat as much as you want of the meals described in the back of this book and lose weight while you do it. Studies time and time again have found vegetarians and vegans, on average, to be thinner than their meat-eating counterparts.11-13 In one recent large study, the researchers found that even if two people ate the same number of calories every day, a person who ate 250 more grams of meat a day would gain 4.4 £ds more every 5 years than someone getting those calories from foods other than meat.14 Two hundred and fifty grams is perhaps the size of a steak, or a little more than a dozen chicken nuggets. The study showed that red meat, processed meats (ham, hot dogs, sausage, luncheon meats, bacon, and so on), and yes, even poultry were associated with increased weight gain.14
Diets containing more healthy, unrefined plants have been shown to prevent or treat a wide range of other diseases. They include kidney disease (including kidney stones), Alzheimer's dementia, gallstones, and certain cancers, including those of the breast, lung, colon, ovaries, uterus, and prostate. Listed below are some of the illnesses shown by published research15 to be associated with improved outcomes with more plant-food intake, or worsened outcomes with more animal-food intake. If there was one pill or one surgical procedure that, without any side effects, got results like those possible with a whole-food, plant-based diet, every single person in America would want to have it.
