Sometimes you have to be hit over the head a few times before you actually get it. You hear about it. You read some articles and reviews. It drifts around in the recesses of the mind. Then finally for some unknown reason you are compelled to actually dig in and find out the details.
This was my experience with the book The China Study, by T. Colin Campbell, PhD, who is the lead researcher on the largest, longest (27 years and still counting), most comprehensive study concerning diet and health ever undertaken.1
Dr. Campbell, early in his research career, was sent to the Philippines to help figure out why young children had such high rates of liver cancer. What he found was that, in addition to Hepatitis B, another factor would hugely increase the occurrence of liver cancer; animal protein in the diet. The children who ate the highest amounts of protein had the highest rates of cancer. These were the children from the wealthiest families. He then came across a study from India that substantiated what he was finding in the Philippines. The Indian researchers looked at two different groups of rats. Each group received the same amount of cancer-causing aflatoxin. One group was fed a 20 percent protein diet, similar to a Western diet. The other group was fed a 5 percent protein diet. Every single rat that consumed the 20 percent protein diet had evidence of liver cancer, while every single rat that was fed the 5 percent protein diet was free of liver cancer. Statistically this was quite powerful. There was no doubt that the protein diet was more important than the powerful carcinogen in determining whether cancer would emerge. Campbell wrote, "It was a defining moment in my career."
Campbell, who was raised on a dairy farm and had been working as a scientist on how to increase protein production, was now forced to look at how the sacred cow of protein might not be what he was raised to believe. He then began a long study of the role of protein on cancer initiation and growth. He found that low protein diets, specifically casein, inhibited the initiation and growth of cancer by aflatoxin. "In fact, dietary protein proved to be so powerful in its effect that we could turn on and off the cancer growth simply by changing the level consumed." Later, when Campbell found the opportunity to study the rural Chinese people, who had low animal protein diets, he was able to add to his own two decades of research in the lab that demonstrated the direct relationship that animal protein had in the development of cancer.
Studying diet and its affects on health outcomes has always been an extremely difficult undertaking as there are so many variables that are impossible to control. Rural China, where people stay in the same village and eat the same diet for most of their lives, if not their entire lives, provided a perfect opportunity for epidemiological research. One can compare and contrast rates of disease outcomes from village to village and then examine what people are doing differently in each village to determine the significant risk factors of the disease. Since all of the people are Han Chinese, genetics are ruled out as a causative factor. The only differences are environmental and behavioral.
In the early 1970's, Chou En Lai, China's number-two leader after Chairman Mao, had terminal cancer. He sanctioned a review of cancer throughout China. A comprehensive survey of death rates from the 12 most prominent cancers in more than 2,400 counties, which represented 880 million (at the time 97 percent) of the population was undertaken. A color-coded map of China, county by county, of cancer mortality emerged from this study. What was striking about this "Cancer Atlas" was the degree of differences between different locations rates of cancers; in some places as much as 100 times different. Note that in parts of Long Island, New York and Marin County, California, breast cancer rates were, at most, up to 20 percent higher than the average and this created front-page headlines.
This cancer atlas intrigued Campbell and he pulled together a team of scientists from Cornell University, Oxford University in the U.K., and China's Academy of Medical Sciences in the Ministry of Health, including the lead researcher on the Atlas itself. According to Campbell, "We were able to create the most comprehensive snapshot of diet, lifestyle and disease ever taken." The New York Times called it "the Grand Prix of epidemiology."2
Because of the depth of detail on death rates and localities, they could look and see if different diseases clumped together. Did certain diseases group together in certain geographic areas? If two diseases grouped together, then their causes could be assumed to be shared. When the disease death rates were analyzed and compared with each of the others, two distinct groups of diseases emerged: diseases of poverty and affluence.
Cancer, diabetes, and coronary heart disease came from economically developed areas and were related to diets of affluence, primarily when the diet is more animal-based. Infectious diseases, intestinal obstruction, peptic ulcers, tuberculosis, parasitic disease, rheumatic heart disease, metabolic and endocrine disorders, and pregnancy complications are diseases of poverty, malnutrition and poor sanitation. A certain area that has a high rate of a poverty type of disease, such as parasites, will not also have a high rate of breast cancer. These areas relied more on plant-based foods.
The China study, which produced more than 8,000 associations between different dietary factors and disease, often pointed to one main factor. The more animal-based foods people ate, the more chronic disease was produced, including cancer and cardiovascular disease, the two biggest killers in the Western world.
Campbell then went on to look at a huge body of research that was already available to confirm his findings. Comparisons of fat intake and breast cancer rates, when broken down by country, showed direct correlation. As fat consumption rose, so did breast cancer. Multiple sclerosis also showed a direct correlation to amount of animal based food consumption by country. Over the course of his career, he began to conclude that one must eat as little animal food as possible. This was a complete about-face from how he was raised.
Contrast this view with that of the Westin Price Foundation, Brian Peskin, Atkins, and the Paleolithic diet. These people feel that animal food is an essential aspect of the human diet. What to do? Let's start where everyone agrees. Plant-based foods that are not processed, are good for you. Processed foods are problematic and need to be avoided. Unfortunately, most animal food is not what Mother Nature intended. Corn-fed animals, factory raised on manufactured feed and then fed antibiotics and hormones, is not what humans evolved with. Once slaughtered, more processing and preserving occurs before it reaches our tables.
Homogenated, pasteurized, preserved in chemicals, hydrogenated, hydrolyzed, and many more human-made processes are perpetrated on both plant and animal foods. Processed foods are available to affluent society, and just might be the real cause of affluent disease seen in country comparisons.
Wild, fresh food is the best but not always available. One rule of thumb I go by when questioning a food choice is to look at the food and ask; did this food exist in this form 200 years ago? Was it a food that was easily attainable 200 years ago? If the answer is yes to both, then eat it and feel good about it. It is a question of quality and quantity. Try to eat in a way that our ancient ancestors ate as much as possible and your cells will be happy.