The China-Oxford-Cornell Study on Dietary, Lifestyle and Disease Mortality Characteristics in 65 Rural Chinese Counties was a study conducted throughout the 1970s and 1980s in rural China, jointly funded by the University of Oxford, Cornell University, and the Government of China. In 1991 The New York Times called it "the Grand Prix of epidemiology."The first two major studies were led by T. Colin Campbell, professor of nutritional biochemistry at Cornell, who summarized the results in his book The China Study (2005).
The study examined the diets, lifestyle and disease characteristics of populations of 65 rural Chinese counties, comparing the prevalence of disease characteristics, excluding causes of death such as accidents. The findings suggested that some diseases of affluence were caused by Westernization, especially the growing consumption of animal protein and dairy products, previously either unknown or uncommon in China.
In his book, Dr. Campbell writes about the Nurses' Health Study, and how the results seem misleading because all of the participants are basically eating the same diet:
The problem of studying a population that uniformly consumes a high-risk diet and looking at the differences in consumption of one nutrient at a time is not unique to the Nurses' Health Study. It is common to virtually all studies using Western subjects. Furthermore, there is little or no value to pooling the results of many large studies for analysis in order to get a more reliable result if all the studies have the same flaw.
Indeed, aren't we lucky that the Chinese tend to eat a pretty different diet than we do, and so we have a population to study to figure out why we're all dying of diseases of affluence? Diversity is wealth! Let's remember that while we're overseas trying to "help" other "poor" cultures that don't have our material wealth.