The
China Project was conceived in 1980-81 during the sabbatic visit
of Dr. Chen Junshi, Deputy Director of Institute of Nutrition and
Food Hygiene, Chinese Academy of Preventive Medicine, to the laboratory
of Professor T. Colin Campbell, Division
of Nutritional Sciences, Cornell
University, Ithaca, NY. A short while later, they were joined
by Professor Richard Peto, University
of Oxford, England, and by Dr. Li Junyao, China Cancer Institute,
Chinese Academy of Medical Sciences and their colleagues in China,
the United States, England, Canada, and France.
Scientific
Justification
In
the late 1970s and early 1980s, there were two principal observations
suggesting a relationship between diet and cancer. First, rich Western
diets (high in fat and meat, low in dietary fiber) were
strongly associated (correlated) with incidence of colon
and breast cancer. Second, migrants moving to areas of different
cancer risks acquired the risk of the country to which they moved,
regardless of their ethnic or genetic backgrounds.
Much
of this was summarized by a US National Academy of Sciences 1982
report on Diet,
Nutrition and Cancer.
In
1981, the Chinese Academy of Medical Science published an Atlas
of Cancer Mortality on the 1973-75 mortality rates for about a dozen
different cancers for 2400 counties in China. These maps showed
that cancer was highly localized in specific geographic regions.
Cancers rates ranged several dozen, even a few hundred fold from
highest to lowest rate areas, far more than the 1.5-2.0 fold ranges
of the US.
Residents
of these regions tended to live in the same regions all their lives
and to consume the same diets unique to each region each and every
year.
Their
diets (low in fat and high in dietary fiber and plant material)
also were in stark contrast to the rich diets of the Western countries.
Study
Design
Sixty
five counties in rural China were selected for study and the dietary,
lifestyle and disease characteristics of populations of each county
were compared.
1983-84
Survey
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Within
each of the 65 counties, 2 villages were selected and 50 families
in each were randomly chosen for study. One adult from each household
(half men and half women), 6500 for the entire survey, participated.
Blood, urine and food samples were obtained for later analysis,
while questionnaire and 3-day diet information was recorded.
A
total of 367 items of information on these 6500 families eventually
were judged to be reliable. These 1983-84 diet and lifestyle data
included the 1973-75 mortality rates for about 4 dozen different
kinds of cancers and other diseases.
1989-90
Survey
- view map
The
same counties and individuals surveyed in 1983-84 were re-surveyed
in 1989-90, with the addition of 20 new counties in mainland China
and Taiwan, and 20 additional families per county, thus yielding
10,200 total adults and their families. A large amount of socioeconomic
information also was collected.
These
data were combined with new mortality data for 1986-88, using the
most recent disease classification scheme (International Classification
of Disease, Edition 9). The data from the second study is now
available on-line at the Clinical
Trial Service Unit & Epidemiological Studies Unit of Oxford
website.
Funding
The
US National Cancer Institute (of NIH), along with the American Institute
for Cancer Research (Washington, DC), provided the initial funds.
The Imperial Cancer Research Fund in England also provided significant
support for the Oxford University activity. Since 1993, the American
Institute for Cancer Research has provided the primary funds.
However,
the majority of the support for this study came from the Chinese
people and their government. This support was 'in kind', resulting
in the provision of approximately 800+ years of professional and
technical labor.
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