Relative to a lot of other things that people should be concerned about, titanium dioxide in my mind, is really low on the list. I would be more worried about some substitutes that people are using for titanium dioxide that don't have decades of research associated with it, said Westerhoff.

For his part, Kaminski argues most of the studies have been in animals, and any effects found were minuscule. He and his team also contested some of the findings in a 2019 study that found no evidence of increased inflammation or changes in the GI tract.

Stability and darkening[edit]