THE CHINA STUDY - and why you should know about it
Back in the 1970s, the premier of China, Zhou Enlai, who was dying of cancer at the time, commissioned a massive survey of 880 million people, representing about 96% of the population of China at that time. The survey looked at the occurrence rates of 12 different types of cancer in 2400 counties across China. It remains a world record in terms of both the number of people studied and the number of researchers involved, which was about 650 000!
The resulting Cancer Atlas showed that cancer rates across China varied greatly from area to area, which suggested that diet and environment were likely the culprits and not genetics. It showed that diseases that were more common in Western countries were just clustered together in certain geographical locations in China and not spread widely across the country as one would have expected.
In the 1980’s, fascinated by these results, Dr T Colin Campbell along with researchers from Cornell University, Oxford university and the Chinese government, embarked on an important epidemiological study to investigate this apparent relationship between disease rates and the diet and lifestyle factors across China. The 65 counties in China that were selected by the researchers to study further were chosen because they had genetically very similar populations that had over generations, lived and eaten in the same way, and had stayed in the same place.
The results were subjected to rigorous analysis and the consistency of the results led to the conclusions that overall, the more closely people followed a plant-based diet, the lower was the risk for chronic disease including many cancers. The death rates from Western “diseases of affluence” were the highest for populations eating animal-based diets, and lowest for those populations eating mostly plant-based diets and these differences were significant!
Other findings highlighted the differences in health outcomes of plant vs animal based diets. Firstly, higher cholesterol in the animal based diets was strongly linked to chronic, degenerative diseases. Secondly, estrogen levels were much lower in Chinese women than western women. These levels correlated to a higher plant food intake which resulted in much lower rates of breast cancer. Finally, the higher the intake of fibre (which is only found in plants - not meat or dairy), the lower the incidence of colon and rectal cancer. Even more reasons to get stuck into those veggies!