The China Study by Thomas Campbell

EXPERIMENTAL DESIGN OF THE CHINA STUDY 355

much of these foods were being consumed. Thus we decided to evaluate

nutritional conditions by analyzing blood and urine samples for indica-

tors (biomarkers) of multiple nutrient intakes. These analyses would be

far more objective than haVing people recall what they ate.

Collecting and analyzing blood, however, was not easy to arrange, at

least not in the way that we preferred. The initial problem was getting

enough blood. For cultural reasons, rural Chinese were reluctant to pro-

vide blood samples. A finger prick seemed to be the only possibility but

this was not good enough. A regular vial of blood would give 100 times

as much blood and allow for analyses of many more factors.

Dr. Junshi Chen of our team, at the Institute of Nutrition and Food

Hygiene in the Ministry of Health, had the unenviable task of convinc-

ing these volunteers to give a regular vial of blood. He succeeded. Sir

Richard Peto at the University of Oxford of our team then made the very

practical suggestion of combining the individual blood samples to make

a big pool of blood for each village for each sex. This strategy gave more

than 1,200-1,300 times more blood when compared with the finger

prick method.

Making big pools of blood had enormous implications and made

possible the China Study, as it later became known. It allowed analyses

of far more indicators of diet and health. This allowed us to consider

relationships in a far more comprehensive manner than would have

otherwise been possible. For more detail on the theoretical and practical

basis for collecting and analyzing blood in this way the reader is referred

to the original monograph of the study.l

After collecting the blood, we then had to decide who would do the

many analyses that were pOSSible. We wanted nothing but the best.

While some analyses were conducted at our Cornell lab and at Dr.

Chen's Beijing lab, the rest of the analyses, especially the more special-

ized types, were done in about two dozen laboratories located in six

countries and in four continents. Laboratories were selected because of

their demonstrated expertise and interest. The laboratory participants

are listed in the original monograph.l

HOW GOOD IS THIS STUDY?
Because this survey was a one-of-a-kind opportunity, we intended that
it be the best of its kind ever undertaken. It was comprehensive; it was
high quality; and its uniqueness allowed new opportunities to inves-
tigate diet and disease that were never before possible. These features