Wegman’s puts titanium dioxide in its Original Macaroni and Cheese. Campbell’s Healthy Request Chunky Chicken Corn Chowder has it, as does Food Club’s Chunky New England Clam Chowder. Marzetti uses the color agent to brighten its Cream Cheese Fruit Dip. Dairy products usually don’t need titanium dioxide to look white, but Kroger has decided to add titanium dioxide to its Fat Free Half-and-Half. And titanium dioxide isn’t only in especially white or brightly colored foods: Little Debbie adds it to Fudge Rounds and many other products. According to the Food Scores database maintained by Environmental Working Group, more than 1,800 brand-name food products have titanium dioxide on their ingredients list. That said, it can still lurk as an unspecified “artificial color,” or labels might simply say “color added.”

A study published in the Journal of Agricultural and Food Chemistry in 2019 sought to examine the effects of titanium dioxide on intestinal inflammation. Researchers did this by feeding rats titanium dioxide nanoparticles and found that, after the course of two to three months, the animals had lower body weights and induced intestinal inflammation. The researchers also found the nanoparticles altered gut microbiota composition and aggravated chronic colitis. The rats also experienced reduced populations of CD4+T cells (which are cells that help organize immune responses by prompting other immune cells to fight infection), regulatory T cells, and white blood cells in mesenteric lymph nodes. The researchers wrote: “Dietary TiO2 nanoparticles could interfere with the balance of the immune system and dynamic of gut microbiome, which may result in low-grade intestinal inflammation and aggravated immunological response to external stimulus, thus introducing potential health risk.”