UPDATE: An article published recently in The Journal of the National Cancer Institute showed that Chinese immigrants are much more likely to develop colo-rectal cancer if they adopt the typical American lifestyle. A group of researchers headed by Dr. Alice Whittemore of Stanford University interviewed a large group of people in the People's Republic of China and a similar group of Chinese-Americans who immigrated to the United States or whose parents had immigrated.
The interviews probed diet, exercise and other health related habits of all the subjects; but with the Chinese-Americans, the researchers explored every aspect of westernization, including such things as the use of herbal medicines, languages spoken at home and even the newspapers read by the family. All of these factors were correlated with the incidence of colon and rectal cancer. The strongest risk factors related to the type of food eaten and the amount of exercise. Chinese-American men, who had four to seven times more colon or rectal cancer than men of the same age in the People's Republic of China, got less exercise and were much more likely to eat high quantities of food rich in animal or dairy fat.A related report (in Contemporary Nutrition, Vol. 14, No. 6, 1989, General Mills) made a fairly comprehensive evaluation of the diet in the People's Republic of China. These researchers found the Chinese diet to contain more than three times the dietary fiber of the American diet (33 grams of fiber per day compared to about 11 grams per day).
An attempt was also made in this report to evaluate the dietary factors that influence the development of diseases of affluence (certain cancers, heart disease, etc.). This analysis indicated that a diet rich in protein, particularly animal protein, may have the greatest potential for enhancing risk for these diseases.
The typical protein intake for the people surveyed in China was around 66 grams per day compared to nearly 94 grams per day in the American diet. More striking was the difference in the amount of animal protein. In China, only about 7 percent of the protein comes from animal sources, compared to about 70 percent from animal sources in America.
There were several other interesting findings in this study. The age of menarche (beginning of menstruation) is markedly delayed among young Chinese women, ranging from 15.2 to 18.9 years. Mean menarcheal age in the United States is around 12 years. Apparently, age at menarche is closely related to early life nutrition. Diets rich in energy, protein, calcium and fat enhance the rate of development and may lead to higher risk of breast and reproductive cancers later in life.
Another interesting finding related to the total caloric intake, which was approximately 20 percent higher in China than in the United States, when body weight is taken into consideration. The body mass index (weight/height, squared) is 20.5 in China but 25.8 for a comparable adult male in the United States. This again substantiates the role of food type and activity levels in the development of obesity. These studies again indicate the need for more complex carbohydrates, less fats and sugars, and a higher activity level for better health.