Diet and gastric cancer in five regions of Japan

Nutrition Research Newsletter, Feb, 1997

Although gastric cancer rates have been declining in Japan in recent decades, this form of cancer is still an important cause of death in both japanese men and women. Despite the relatively homogenous nature of the Japanese population, there is a threefold difference in gastric cancer-mortality rates in different parts of the country. Regional dietary differences may be at least partly responsible.

In this ecologic study, 634 men aged 40-49 years and 373 of their wives completed food frequency questionnaires. The participants lived in five different districts of japan, including two districts with high mortality rates from gastric cancer (Akita and Tokyo), two with intermediate rates (Nagano and Iwate) and one with the lowest rate in the country (Okinawa).

Of the P food items included in the questionnaire, 32 showed significant differences among the districts for the men and B for the women. Men and women from Okinawa, where gastric cancer mortality is lowest, consumed more beef, cheese, and oolong tea and less rice, blue fish, crab/shrimp, shellfish, fruit, apple, pickled vegetables, mushrooms, and soybean products than those in other districts. Participants from Akita and Tokyo, with the highest gastric cancer mortality rates, ate green vegetables and yellow vegetables less frequently than those in other regions. The gastric cancer mortality rate was positively associated with the consumption of rice, pickled vegetables, and bean paste soup, and negatively with green vegetables and yellow vegetables.

These findings indicate that dietary factors may contribute to the interregional differences in gastric cancer mortality within Japan. The observed positive associations with pickled vegetables and bean paste soup (two major sources of sodium in the japanese diet) are consistent with previous reports associating increased risk with higher urinary sodium excretion. The negative associations with green and yellow vegetables are consistent with the findings of case-control and cohort studies within populations.

Yoshitaka Tsubono, Minatsu Kobayashi, and Shiochiro Tsugane, Food Consumption and Gastric Cancer Mortality in Five Regions of Japan, Nutrition & Cancer 27(1):60-64 (1977) [Correspondence: Yoshitaka Tsubono, Epidemiology and Biostatistics, National Cancer Center Research Institute, East, Kashiwa 277, Japan]