Dietary fibre in the Japanese diet.

The low risk of colon cancer among the Japanese suggests their high intake of dietary fibre. Composite diet mixtures for 1959, 1970, and 1979 were prepared utilising the food consumption data from the National Nutrition Survey in Japan and analysed for non-starch polysaccharides (NSP) at the Dunn Clinical Nutrition Centre in Cambridge. The results showed that average intake of NSP by a Japanese in the above years did not exceed 13 g per day, which is as low as the corresponding intake by the Scandinavians and the British whose risk of colon cancer is known to be high. Since all the materials were analysed by the same methods and at the same laboratory, the results are well comparable and indicate that the low risk of colon cancer among the Japanese cannot readily be explained by their intake of NSP alone.