Dietary determinants of colorectal proliferation in the normal mucosa of subjects with previous colon adenomas

Dietary determinants of colorectal mucosa proliferation were studied in 69 subjects previously operated for at least two sporadic colon adenomas, Info rmation on recent dietary habits was collected by a validated food frequenc y questionnaire, and proliferation was measured by [H-3]thymidine incorpora tion in colorectal biopsies by determining the labeling index (LI) and the percentage of LI in the upper part of the crypt, two parameters that are in creased in subjects at high risk of colon cancer. The LI was significantly higher in women as compared with men (P = 0.01). Diet showed several associ ations with colorectal mucosa proliferation: (a) subjects in the highest te rtile of fish consumption had a significantly lower LI (P = 0.0013) compare d with those in the lower tertiles [5.20 +/- 1.87 versus 6.80 +/- 2.18 (mea n +/- SD)]; (b) subjects with a low red meat consumption had lower prolifer ation in the upper part of the crypt [2.38 +/- 2.10, 5.30 +/- 4.62, and 5.8 9 +/- 4.82 in the low, middle, and high tertile of consumption, respectivel y (mean a SD); P = 0.0093]; (c) according to estimated nutrient intakes, th e LI was lower in subjects reporting a high intake of starch (P = 0.006) an d higher in subjects with a low intake of beta-carotene (P = 0.002). The re sults show that subjects reporting a diet rich in fish, starch, and beta-ca rotene and low in red meat had lower colorectal mucosa proliferation and a normal pattern of proliferation along the crypt, Given the correlation betw een colorectal proliferative activity and colon cancer risk, such a dietary pattern might be beneficial for subjects at high risk of colon cancer.