In a 2021, Chinese researchers examined the impact of E171 on lipid digestion and vitamin D3 bioaccessibility in a simulated human gastrointestinal tract model. They examined Vitamin D’s bioaccessibility, or the amount it was released in the gastrointestinal tract, becoming available for absorption, and found it “significantly decreased from 80% to 74%” with the addition of E171. In the experiment, E171 decreased lipid digestion dose-dependently. Researchers wrote: “The findings of this study enhance our understanding toward the potential impact of E171 on the nutritional attributes of foods for human digestion health.”  The study was published in the Journal of Agricultural and Food Chemistry, 

In the meantime, some big manufacturers boosted their product pricing to better their margins, such as Venator, which increased its titanium dioxide prices by roughly 160 USD /MT for the third quarter of 2021 in the North America region. Overall, prices for Anatase grade in the United States hovered about 3485 USD /MT through the end of June.

No acute effects of nano-sized TiO₂ were observed in Danio rerio (zebrafish) embryos. Exposure of rainbow trout to TiO₂ NPs triggered lipid peroxidation, influence on the respiratory tract, disturbance in the metabolism of Cu and Zn, induction of intestinal erosion  and accumulation in kidney tissue. Linhua et al. exposed juvenile carp to 100 and 200 mg/ml of particles and TiO₂ observed no mortality. However, the fish suffered from oxidative stress and pathological changes in gill and liver. In the infaunal species Arenicola marina, exposure to TiO₂ NPs in sediment caused sub-lethal effects including decrease in casting rate and increase in cellular and DNA damage. Aggregated particles were visible in the lumen of the gut, but no uptake through the gut or the skin was observed.

The integrity of surface skin cells was evaluated with and without solar simulated irradiation. The integrity of the stratum corneum was significantly lower in individuals treated with P25TiO₂NPs under the light in comparison to the ones that received the functionalized nanoparticles. Cell membrane suffering is evident (Fig. 9), and it is in accordance with the ROS levels and macromolecule oxidation found in vitro for the irradiated P25TiO₂NPs. Disruption of the superficial skin layer was observed in all animals treated with no functionalized nanoparticles, under irradiation. This data expands the findings by the group of Professors Fubini and Fenoglio, who showed that P25TiO₂NPs could impact the lipid structure at the top few microns of the stratum corneum [55]. Control skin under irradiation and without any topic formulation did not show changes in cell structure.

Neutral White, 26 per cent zinc sulphide, 66 per cent barium sulphate, 5 per cent infusorial earth, 3 per cent whiting.

We've measured many different immunological markers, both in the mucosa of the intestine and the lymphoid organs part of the intestine and we didn't see any inflammation there or changes in white blood cell number, Kaminski said. They also looked at the spleen where titanium dioxide was taken up into the bloodstream. You would expect [titanium dioxide] would be filtered out in the spleen and maybe induce inflammation there, but we did not see that, Kaminski added.

However, humans are not exposed to E171 in drinking water at any significant quantity over a long duration, so this potential effect is irrelevant to the human experience. It’s important to understand that a potential hazard is not the same thing as an actual risk. 

A1:

Above 20%, it is recommended to replace 1 kg TiO2 with 1.3 kg of lithopone supplier 30%.  

Other experts say there is simply no conclusive evidence at this point that titanium dioxide is damaging to humans after ingesting. Kaminski in particular said the research studies cite health hazards that were found by using high doses of the product, which you would not normally see in food.

How is titanium dioxide extracted?

Food additive or carcinogen? The growing list of chemicals banned in EU but used in US, by Mikaela Conley, The Guardian, June 23, 2022

Other food products that list titanium dioxide are Lucerne cottage cheese, Beyond Meat's chicken plant-based tenders, Great Value ice cream and Chips Ahoy! cookies.