Can we learn something from the Chinese when it comes to eating habits? Yes, if we are interested in good health. At least that is the opinion of Professor T. Colin Campbell of Cornell University who authored The China Study, a best seller that claims to road to good health is paved with vegetables and fruits with no animal in sight. A vegan diet, he claims, is the answer to beating the ailments of western civilization, namely heart disease, cancer and diabetes. His opinion is forged by one of the most extensive epidemiological studies ever carried out, a collaborative effort between Cornell and Oxford Universities and the Chinese government back in the 1980s. China seemed to be an ideal place to study the relationship between diet and disease because of genetic uniformity but widespread differences by region in diet and disease patterns. Furthermore, residents tend to spend their lives in the same area and consume the same foods which are unique to each region. Whereas in North America cancer rates vary only about two fold from highest incidence regions to the lowest, in China the variation can be as much as a hundred fold. That was certainly deemed worthy of investigation. Researchers randomly selected 50 families in 2 villages in each of 65 counties from whom blood samples were obtained along with 3 day food diaries. The massive amount of data collected were analyzed and related to mortality rates that had been compiled a decade earlier for different kinds of cancers and other diseases. According to Dr. Campbell, the overall results could be summarized quite simply. The more animal protein consumed, the greater the toll of disease. From this he extrapolated to suggest that the ideal diet would contain no animal protein at all.
Campbell’s interpretation of the data has been accepted by some with quasi religious fervor and roundly criticized by others. This is not surprising in the ambiguous world of nutrition where pet theories abound and numerous experts claim to have solved the mystery of what constitutes the ideal diet. The problem is that they don’t agree on what that solution is. Low fat, low carb, vegan and paleo all have their champions. Colin Campbell is firmly planted in the vegan camp, no meat or dairy cross his lips. But that is not like any Chinese diet he studied. The Chinese do eat meat of all kinds, albeit not as much as North Americans. And there has been plenty of criticism from statisticians who claim that Campbell dredged the data to conform to a preconceived notion. Arguments fly back and forth with each side flinging muddy statistics at the other. Campbell’s supporters point at a study carried out by Dr. Caldwell Esselstyn that showed regression in coronary disease among patients who adhered to a strict vegan diet that allowed no nuts, no avocados and no oils of any kind. But the study involved only a handful of patients who were also treated with statins, so it was not a diet-only trial. It would have been more meaningful had there been a control group not treated with statins. What are we to make of all this? There is enough evidence to suggest that in North America we eat too much meat and the dairy industry has convinced us that its products should be consumed at every meal, which is not supported by evidence. And there is certainly no evidence that nuts or avocados are harmful, in fact there is evidence to the contrary. So yes, the plate should be mostly filled with vegetables but there is no data to support the total elimination of meat.