Figure 6. Chronic exposure to food-grade TiO₂ triggers low-grade inflammation and initiates preneoplastic lesions.

Rats were orally exposed to 10 mg/kg of BW/day of E171 in drinking water (black bars, 11 rats) or to water only (white bars, 12 rats) for 100 days. (a) The number of rats with or without aberrant crypt foci (ACF) in the colon and (b) ACF (arrowheads) at the colonic mucosal surface stained with methylene blue (40X) drawn from two ACF-positive rats. (c) Cytokine assays in colonic mucosa. The data are written as the mean ± s.e.m. (n = 10 to 11 rats/group). *P < 0.05, **P < 0.01 vs. the control: (a) contingency analysis followed by Fisher’s exact test for ACF analysis, and (c) Student’s t test.