Consumption of plant foods and stomach cancer mortality in the seven countries study. Is grain consumption a risk factor? Seven Countries Study Research Group.

Plant foods are generally considered to be beneficial for health. A higher consumption of fruits, and to a lesser extent vegetables, is consistently associated with a lower risk of stomach cancer. Results on the association between stomach cancer and grain consumption are less clear. We associated plant food consumption with 25-year stomach cancer mortality at population level in the Seven Countries Study. Around 1960, > 12,000 men aged 40-59 years from 7 countries and 16 cohorts were enrolled. In each cohort, dietary information was collected in small random samples. Crude and adjusted associations were calculated for a change of 10% of mean intake. Results differed for the plant foods studied: an inverse association was observed for fruits (adjusted rate ratio = 0.96, 95% confidence interval = 0.91-0.99), a positive relation for refined grains (adjusted rate ratio = 1.07, 95% confidence interval = 1.03-1.12), and no association for total plant foods, vegetables, whole grains, and potatoes. A high intake of refined grains was correlated with a low consumption of fruits. In conclusion, high intake of refined grains may increase stomach cancer risk. However, because adjustment could only be limited in this study, high intake of refined grains may just reflect the deleterious effect of a diet low in fruits or other characteristics associated with low fruit consumption.