The China Study, sponsored by Cornell and Oxford Universities and conducted by T. Colin Campbell, PhD, concludes that consuming animal products causes chronic disease, and advocates a plant-based diet. It is often cited by people who favor plant-based diets.
Establishing causal relationships between diet and disease via statistics-based population studies can be difficult. Correlations in data are often mistaken for causation, especially when someone is trying to prove a point. Beyond that, there are always many variables to consider, and it's nearly impossible to control for them all.
Still, scientists and epidemiologists are experts at this sort of thing: it's what they're trained to do. Right?
I just read
this excellent critique of The China Study, on Denise Minger's blog. Take a look and see what you think. I find no fault with it.
It is fascinating to me that an amateur (albeit a very smart one) can find fundamental problems with research sponsored and carried out by professionals with years of training and huge budgets.
Is T. Colin Campbell a careless scientist? Unlikely.
Do Cornell, Oxford, and T. Colin Campbell have an agenda that they are advancing, besides improving public health? Campbell may be motivated by financial considerations, but what about the others who reviewed his work?
Is it that the "plant-based diet" has become the flavor-of-the-day, and that scientists who want funding must cleave to this dogma?
The physicist Max Planck once said, "An important scientific innovation rarely makes its way by gradually winning over and converting its opponents. What does happen is that its opponents gradually die out, and that the growing generation is familiarized with the ideas from the beginning."
What Planck does not mention is that the validity or utility of a new scientific paradigm is not the only deciding factor in its acceptance. A powerful, multi-decade marketing campaign can affect the thinking of an entire generation of up-and-coming scientists and lay-people.
In physics, we have string theory, which is not verifiable and predicts nothing measurable, yet has dominated theoretical physics for decades. Many young physicists are "string theorists", having spent their professional lives working in string theory. They are invested, literally, in its continued popularity.
In nutrition theory, we have low-fat, which was promoted masterfully by Ancel Keys from the 1950s through the 1970s. Health in the US has gone sharply downhill in the forty years since low-fat hit the mainstream. Of course this is merely correlation, not necessarily causality, and of course there are many other variables involved. But modern nutritionists and dietitians are invested in the low-fat paradigm, and are reluctant to consider that it might be wrong.
Could it be that low-fat is grounded in marketing rather than good science?