Science Based: The China Study

by MKI

The China Study got a 48% scientific accuracy rank from the non-biased Red Pen Reviews folk (non-funded scientist reviews, sharp guys). Check out the link. Quick summary:

We evaluated three key claims of The China Study:

  1. Animal foods such as dairy and meat are a major cause of cancer, particularly due to the type of protein they contain.
  2. Animal foods are a major cause of cardiovascular disease.
  3. A whole food, plant-based diet prevents and reverses cardiovascular disease.

The book received an overall scientific accuracy score of 1.9, indicating that its scientific claims are not very well supported. However, this varied greatly between the three claims we evaluated. We found little compelling evidence to support the claim that animal protein in general causes cancer, somewhat more evidence to support the claim that animal foods contribute to cardiovascular disease, and fairly compelling evidence that a whole food, plant-based diet prevents and reverses cardiovascular disease.

Although one of the authors of The China Study, Campbell Sr., was involved in generating much of the science that underlies the book’s claims, upon close inspection, we found that this evidence was often represented inaccurately in the book. In particular, the large observational study in China the book is named after does not support the central claims of the book. We confirmed this by consulting the original data at the University of Washington medical library and analyzing it with the help of a professional statistician, Karl Kaiyala, PhD. In addition, The China Study omits important evidence that undermines its claim that animal protein but not plant protein increases cancer risk in rodents.

That said, there is fairly convincing evidence from randomized controlled trials and basic science research that a whole food, plant-based diet reduces the risk of cardiovascular disease. However, it remains unclear whether the observed effects are due to reducing intake of animal foods per se, vs. other diet changes like reducing intake of refined carbohydrates or greater fiber intake. The China Study tends to accurately cite this evidence, but sometimes withholds important caveats about the weakness of certain study designs, including that the China Study itself uses a study design that cannot yield confident conclusions about diet-health relationships.