SOME SNIPPETS OF INFORMATION FROM THE CHINA PROJECT

T Colin Campbell

[ Further details of the study I Author's resume I Exclusive Interview ]


Background


This is the most comprehensive project on diet and disease ever undertaken. Two major surveys were undertaken, 1983 and 1989-90. These surveys were undertaken in China because cancers and various other diseases exhibit exceptional geographic localization. Thus, it made sense to examine these local regions to determine the responsible dietary and lifestyle factors.

In a 1983 survey, 367 items of information were collected on how people live and how they die in 138 rural Chinese villages; 6500 adults and their families were surveyed. In a 1989-90 survey, more than 1000 items of information were collected in 170 villages in rural China and Taiwan, involving 10,200 adults and their families. These new data, including a large number of socioeconomic characteristics, will be combined with a new survey on causes of death for a population of 100 million (1.4 million death certificates for the years, 1986-88).

There are sufficient data available in these combined surveys to interpret for the next 20+ years -- at least. The opportunities for exploration of the causes of disease, both specifically and generally, are incalculable. We believe that these data have the potential to establish a new paradigm for thinking about nutrition and health -- for all countries, rich and poor, East and West, North and South.

Public recognition given to project


The project has been featured as a cover or lead story in numerous news print media, including the New York Times, the China Daily, USATodgy, and the Boston Globe, among many others, and at least in part or whole, in several TV documentaries shown in Tokyo, Seoul, Rio de Janeiro, Beijing, London, Frankfurt and US cities.

In an analysis of food trends prepared by Smith Barney Shearson, the banking investment firm, the China Project was said to be the "seminal', work driving the current marketplace trends; furthermore, it was said to have been undertaken with "rigorous methodology".

Some findings from the 1983 survey


The dietary patterns in China are strikingly different from Western countries, the major difference being the consumption of foods of animal origin. Animal protein intake, for example, is 10-fold greater, on average, in the US. than in China.

Although the biology of the diet and disease relationship is infinitely complex and is easily misunderstood when interpreted in a reductionism manner, the main nutritional conclusion from this study is the finding that the greater the consumption of a variety of good quality plant-based foods, the lower the risk of those diseases which are commonly found in western countries (eg., cancers, cardiovascular diseases, diabetes). Based on these and other data, we hypothesize that 80-90% of all such diseases could be prevented before about age 90 years.

The optimum lifetime blood cholesterol concentration may be as low as 100-125 mg/dL (compared to an average concentration of about 210 mg/dL in the US.).

The same dietary factors which increase blood cholesterol concentrations among Americans (at the much higher ranges) also increase cholesterol at the lower concentrations of the Chinese; these include, for example, increased intakes of dietary fat and animal protein and decreased intakes of dietary fiber and legumes. Moreover, the lower the blood cholesterol, the lower the risk for various cancers; there is no evidence of a cholesterol threshold below which further decreases in disease would not occur. These two facts are quite remarkable, in that they suggest that almost any consumption of animal-based foods (higher in fat, lower in fiber) may increase blood cholesterol (among many other biochemical changes) from a very low level, this to be followed by a significant increase in the prevalence of the degenerative diseases (many other analyses of these same data for individual diet-disease relationships support this interpretation).

Chinese consume more total calories (per unit of body weight), yet have far less obesity than AMericans, probably accounted for both by greater physical activity and greater consumption of a low fat, plant-based diet. chronic infection with hepatitis B virus is a major cause of primary liver cancer. Together with the highly significant nutritional findings, this cancer appears to be a viral/nutritional disease, not a viral/chemical carcinogen disease as previously thought (our data on this question are more comprehensive than all others combined, thus our conclusion on the role of nutrition, even though different, is highly relevant). Control of the prevalence of this disease may be best achieved through immunization of young children. Prevention of disease progression among individuals who suffer chronic hepatitis infection may be best achieved through strict adherence to a low fat, plant based diet.

Consumption of salt-preserved ("pickled') vegetables increases stomach cancer while consumption of fresh vegetables decreases this cancer.

Provided there is adequate dietary variety and quantity of plant-based foods and an otherwise good public health environment, achievement of adult height can be maximized without consuming animal-based foods.

Breast cancer, low in China, nonetheless is greater with the consumption of the typical Western diet (high in animal- based foods and fat, and low in plant-based foods) which encourages body growth rates to be too rapid, and sexual maturation to occur too early.

More speculative ideas


Chronic infection with Herpes virus may increase coronary heart disease.

Chronic infection with schistosomiasis, an intestinal parasite, may increase the risk for colon cancer.
Increased consumption of cadmium, a toxic heavy metal, may increase liver cancer. Infection with Helicobacter pylori (a bacterium) is a risk factor for stomach cancer. implications of this study

Conclusions drawn from this and other studies suggest that it should be possible to simultaneously reduce diseases typically found either in Western industrialized countries or in developing countries (of this, we have considerable confidence).

If all countries were to use the dietary and lifestyle recommendations emerging from this study, it is estimated that the reduction of disease burden would result in an enormous savings in health care costs. (At least $120 billion per year in the US alone might be saved).

The savings in utilization of the earth's resources resulting from the use of fewer livestock for human food also should be enormous.

Developing countries should continue to use their traditional plant-based diets, but give more emphasis to food quality and variety (of plant-based foods). This will constitute an enormous savings in future capital otherwise needed to sustain a western-type food production system in these countries. Land use in these countries would be more environmentally friendly and equitable, thus providing a more politically stable condition.

The optimum diet for peoples residing in all countries of the world appears to be virtually the same.

The present dietary guidelines, mostly focused on the effects of dietary fat when reduced to 30% of calories, is not likely to yield the disease prevention benefits originally inferred.

At least 97-98% of the available data are yet to be analyzed, interpreted and published.

T. Colin Campbell

Project Director China-oxford-Cornell Diet and Health Project

Division of Nutritional Sciences Cornell University Ithaca, NY


Colin Campbell, who was trained at Cornell (M.S., Ph.D.) and MIT (Research Associate) in nutrition, biochemistry and toxicology, spent 10 years on the faculty of virginia Tech's Department of Biochemistry and Nutrition before returning to the DiviSion of Nutritional Sciences Cornell in 1975 where he presently holds the endowed chair of Jacob Gould Schurman Professor of Nutritional Biochemistry. His principal scientific interests, which began with his graduate training in the late 1950's, has been on the effects of nutritional status on long term health, particularly on the causation of cancer. He has conducted original research both in laboratory experiments and in large-scale human studies; in addition, he has participated in multiple deliberations on state, national and international policy matters, has lectured extensively, and has authored over 300 research papers. In addition, he:

In summary, he has been interested both in original research investigation (particularly on the effects of dietary protein on health outcomes) and in the application' of this information for national policy and public information.