T. Colin Campbell is a retired professor of nutritional biochemistry at Cornell University who is on a mission to share his compelling research on nutrition and diet with the world.
T. Colin Campbell is a retired professor of nutritional biochemistry at Cornell University who started his career doing research on how to make animals grow faster. His goal was to promote better health by advocating the consumption of more meat, milk and eggs. Then, more than 40 years ago, while he was a young researcher working on a project to help stamp out malnutrition in the Philippines, he came to a turning point that shifted the direction of his life's work. Now he's on a mission to share his compelling research on nutrition and diet with the world. He wrote a book called The China Study, (BenBella Books, 2005), based on his years of research showing the connection between nutrition and heart disease, diabetes and cancer. The study was the culmination of a 20-year partnership among Cornell University, Oxford University and the Chinese Academy of Preventive Medicine.
Here are a few answers to the Diet Detective's questions from the man whose research could be responsible for saving our lives by changing our diet.
Diet Detective: Do we really need to be so worried about exactly what we're eating? Have we blown our "unhealthy" eating habits out of proportion?
Dr. T. Colin Campbell: Yes, and no. We obsess about details (which nutrients, which supplements, which specific ailments and diseases are candidates for therapy) but do not pay enough attention to the big picture (whole foods versus processed foods, plant versus animal source foods). Understanding the big picture has the most to offer - by far.
Diet Detective: Could you tell us briefly about the genesis of The China Study?
Dr. T. Colin Campbell: In 1981, the Chinese government announced the results of a massive nationwide survey of cancer mortality for 2,400 counties, which showed that cancer was far more common in some areas than in others. Geographic localization was far more intense than in the U.S. because the vast majority of people in China resided in the same place all their lives and consumed locally produced food, at least in rural parts of the country. Americans move around and consume food from places far and wide, making it virtually impossible to do such a study.
Also, dietary lifestyle characteristics of people in rural China were substantially different from people in Western societies. These conditions presented an unparalleled and unique opportunity to compare diet, lifestyle and disease mortality rates with Western societies. It also allowed us to compare our results with our extensive and provocative laboratory animal findings obtained during the previous 15 years. I especially wanted to record as many different kinds of diet and lifestyle factors as possible in order to get information on "big picture" questions that seemed to be so contentious in the scientific and public communities.
Diet Detective: In your book you state that, "Among the many associations that are relevant to diet and disease, so many pointed to the same finding: People who ate the most animal-based foods got the most chronic disease. Even relatively small intakes of animal-based food were associated with adverse effects. People who ate the most plant-based foods were the healthiest and tended to avoid chronic disease." There are some who disagree with this nutritional philosophy.
Dr. T. Colin Campbell: I don't like to respond to the assertion that people make decisions on the basis of "philosophy," which suggests that people are motivated by personalized agendas in making their decisions. Although I know this to be true for most people, this is not what motivated me. I simply did the research with my many students and colleagues and produced experimental findings that were peer-reviewed and published in the very best scientific journals. I then made my conclusions on the basis of actual empirical data. There was no philosophy involved. If I had a personal bias or philosophy in drawing my conclusions, it would have been exactly the opposite of these conclusions, given my many years on the farm milking cows.
My observation that "even relatively small intakes of animal-based food were associated with adverse effects" comes from the data showing that there is a high statistical significance between blood total cholesterol and aggregate chronic disease rates (i.e., "Western" diseases). This is especially interesting because dietary animal-based protein in this survey ranged only from 0 percent to 10 percent of total protein. Moreover, to observe such statistical significance within this very low range of animal-based protein and within such a low range of blood cholesterol is striking, especially when the blood cholesterol was so highly correlated with animal-source foods.
Diet Detective: Are you suggesting that we all become vegetarians?
Dr. T. Colin Campbell: I have never suggested that we should all be vegetarians, because about 90 percent of vegetarians are still consuming food (i.e., dairy, eggs) with nutrient compositions that actually account for the adverse health effects of animal-based foods. Although consuming foods that trend in the direction of better health, vegetarians do not do what they could do. This suggests that vegans should do better, but they, too, compromise their potential benefits because they consume food that is highly processed. My recommendation is to consume a whole-food, plant-based diet without supplementing with added fat, salt, sugar and processed foods.
Whether people should eat this way is, of course, their choice. Besides, we know that a few people (5 percent) can deviate from this practice and still enjoy good health until advanced ages. But this may be analogous to the small number of smokers who live to their 90s and believe that it was their smoking that got them there. If we want to maximize our health, I believe that it would be prudent to go the whole way to an all-plant-based diet and allow ourselves the opportunity to discover some hidden and delicious tastes that are masked because of our addictions to high fat, salt and sugar. Who can calculate the 1 in 20 chance that they might escape the hazards of eating the wrong food? The real question is whether 100 percent plant-based diets are healthier than, say, 90 to 95 percent plant-based diets. This will undoubtedly depend on the differing responses of each individual, although I know of no scientifically valid data showing that people consuming a plant-based diet suffer more and die earlier. Indeed, the findings are clearly to the contrary.
Diet Detective: You also claim that your research showed that the protein casein, which makes up 87 percent of cow's milk protein, promoted all stages of the cancer process. Are you saying that animal protein promotes cancer?
Dr. T. Colin Campbell: In our experimental animal studies, casein as an animal protein promotes cancer, in spades. Of all the experimental research my laboratory did, this may be the most convincing. In fact, our findings, done in so many ways, show that casein is the most relevant chemical carcinogen ever discovered. I have presented this information in seminars to virtually all the relevant agencies and research groups who do these kinds of studies, and have published the results in the very best peer-reviewed scientific journals. These findings also are consistent with similar promoting effects of casein on the development of experimental atherogenesis (the lesion leading to heart disease) and rising blood cholesterol levels, among other toxic events.
Diet Detective: What is the healthiest diet to prevent disease and live our best life?
Dr. T. Colin Campbell: The closer we get to a whole foods plant-based diet with minimal or no use of added oil, sugar, salt or processed foods, the healthier we will be. On interpreting the scientific evidence, I mostly rely on statistical odds and biological plausibility, which overwhelmingly point in the direction of a plant-based diet. But I become substantially convinced when I see the clinical evidence achieved by my physician colleagues.