Associations of food and nutrient intakes with serum IGF-I, IGF-II, IGFBP-3, TGF-b1, total SOD activity and sFas levels among middle-aged Japanese: the Japan Collaborative Cohort study.

No observational study has examined whether cancer-related biomarkers are associated with diet in Japanese. We therefore assessed sex-specific food and nutrient intakes according to serum IGF-I, IGF-II, IGFBP-3, TGF-b1, total SOD activity and sFas levels, under a cross-sectional study of 10,350 control subjects who answered the food frequency questionnaire in the first-wave nested case-control study within the Japan Collaborative Cohort Study. For both men and women, IGF-I levels were associated with higher intakes of milk, fruits, green tea, calcium and vitamin C. IGF-II levels were associated with higher intakes of milk, yogurt, fruits and miso soup, and lower intakes of rice, coffee and carbohydrate. IGFBP-3 levels were associated with higher intakes of milk, yogurt, fruits and vitamin C, and lower intakes of rice, energy, protein, carbohydrate, sodium and polyunsaturated fatty acids. TGF-b1 levels were associated with lower intakes of coffee intakes, and higher intakes of miso soup and sodium. Total SOD activity levels were associated with lower intakes of most nutrients other than energy, carbohydrate, iron, copper, manganese, retinol equivalents, vitamin A, B2, B12, niacin, folic acid, vitamin C and fish fat. sFas levels were associated with higher intakes of manganese and folic acids. The results of the present study should help to account for findings on those biomarkers regarding risks of cancer and other lifestyle-related diseases in terms of dietary confounding as causality.