The updated evaluation revises the outcome of EFSA’s previous assessment published in 2016, which highlighted the need for more research to fill data gaps.
In a 2017 study published in Scientific Reports, researchers exposed rats to human-relevant levels of E171 to examine the effects of intestinal inflammation and carcinogenesis. They saw that “a 100-day E171 treatment promoted colon microinflammation and initiated preneoplastic lesions while also fostering the growth of aberrant crypt foci in a chemically induced carcinogenesis model.” They continued: “Stimulation of immune cells isolated from Peyer’s Patches [which are clusters of lymphoid follicles found in the intestine] showed a decrease in Thelper (Th)-1 IFN-γ secretion, while splenic Th1/Th17 inflammatory responses sharply increased,” researchers wrote. “A 100-day titanium dioxide treatment promoted colon microinflammation and initiated preneoplastic lesions.” The scientists concluded: “These data should be considered for risk assessments of the susceptibility to Th17-driven autoimmune diseases and to colorectal cancer in humans exposed to TiO2 from dietary sources.”
As for titanium dioxide, the FDA approved titanium dioxide for use as a food additive in 1966. The last time the agency reviewed the additive’s safety, according to the Guardian, was in 1973.
The vitaminB2@TiO2NPs were obtained at room temperature, by a method developed after trying several ratios of reactants. Briefly, 0.02 g of P25TiO2NPs were dispersed in 1 mL of ultra-pure water and stirred in a Vortex. Next, 200 μl of vitamin B2 dissolved in ultra-pure water (5.3 × 10−3 M) were added to 200 μL of P25TiO2NPs and the mixture was ultrasonicated for 1 hour to achieve a deep-yellow homogeneous suspension. The pellet obtained after centrifuging the suspension for 10 min at 4500 rpm was resuspended in ultrapure water, centrifuged again, and then lyophilized.
