AN ECOLOGICAL STUDY ON DIET NUTRITION AND CANCER IN JAPAN/

Correlation or ecological studies may be useful in identifying cancer risk factors which are distributed relatively homogeneously within a p opulation, but differ greatly between populations or between different periods within a given population. In Japan, the westernization of di etary habits has progressed remarkably in the last few decades and may have resulted in changes of incidence/mortality rates of diet-related diseases, especially cancer. Based on data from the National Nutritio nal Survey of Japan (1955-1993) and the vital statistics of Japan (195 5-1993), we conducted correlation analyses between food/nutrient intak e and cancer mortality. The present study on chronological correlation s suggests the relationship between westernized dietary habits and mor tality by cancers of the colon, breast, ovary and prostate and also th e relationship between traditional Japanese dietary habits and mortali ty by stomach cancer. Our results suggest the importance of diet in th e etiology of diet-related cancer. Further observation and analyses ar e needed to confirm the relationship between food/nutrient intake and cancer mortality, while also considering the consumption of tobacco an d alcohol and improvement in cancer diagnostic and therapeutic techniq ues. (C) 1997 Wiley-Liss, Inc.