Consumption of Plant Foods and Stomach Cancer Mortality in the Seven Countries Study. Is Grain Consumption a Risk Factor?

Abstract

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.

Glycemic load, glycemic index and carbohydrate intake in relation to risk of stomach cancer: A prospective study

“…21 A number of epidemiologic studies, mainly casecontrol investigations, have reported an increased risk of stomach cancer associated with high consumption of starchy foods with high glycemic index, such as white bread, rice and potatoes. [1][2][3][4][5][6] Such foods are also relatively low in antioxidants and other micronutrients that might be protective in stomach carcinogenesis.…”

“…1 In this regard, several case-control studies have found an increased risk of stomach cancer associated with high consumption of refined grains and starchy foods. [1][2][3][4][5][6] Most refined-grain products and starchy foods are rapidly digested in the gut and have a high glycemic index. 7 The glycemic index is a measure used to rank carbohydrate-containing foods by their glycemic response and, hence, their effects on blood insulin concentrations.…”

Whole-Grain Intake and Mortality from All Causes, Cardiovascular Disease, and Cancer: A Systematic Review and Dose-Response Meta-Analysis of Prospective Cohort Studies

“…Of 11 studies that reported RRs for cancer mortality (11,12,15,16,22,24,35,36,38,44,45), 3 studies reported a protective association (16,44,45), and 8 others did not find any significant association (11,12,15,22,24,35,36,38). All studies except 4 (18,35,36,40) adjusted for age (n = 15). Most cohorts controlled for some conventional risk factors, including BMI (n = 15), smoking (n = 18), and alcohol For adjustments, 1 = age, 2 = BMI, 3 = smoking, 4 = alcohol consumption, 5 = physical activity, 6 = other dietary variables or nutrients, and 7 = total energy intake.…”

“…We also did not include 2 studies (33, 34) conducted on patients with heart failure (34) and colorectal cancer (33) in the analysis, because subjects in these studies were not representative of the general population and they might have changed their diets after diagnosis of the disease. Three studies (35)(36)(37) that reported RRs for whole-grain intake as a continuous variable were excluded from the meta-analysis; however, these studies were included in the systematic review. Required information (RRs for highest compared with lowest intake of whole grain or RRs for fatal MI) for these studies could not be obtained even by contacting the authors.…”

“…Finally, 20 cohort studies (11, 12, 14-18, 22, 24, 35-45) were included in the systematic review and 17 prospective cohort studies (11, 12, 14-18, 22, 24, 38-45) were included in this meta-analysis: 11 for all-cause mortality (11, 14, 15, 18, 22, 24, 38-40, 43, 45), 11 for CVD mortality (11,15,17,22,24,38,39,(41)(42)(43)45), 6 for total cancer mortality (11,15,22,24,38,45), and 4 for specific cancers mortality (12,16,24,44) (Figure 1). Of the 20 studies included in the systematic review, 9 reported intake of total whole grain (11,12,14,15,22,35,37,43,45), and 11 others reported the intake of specific whole-grain foods (16-18, 24, 36, 38-42, 44).…”