In a 2022 study published in the Journal of Hazardous Materials, scientists wanted to examine the effects of titanium dioxide as a food additive on atherosclerosis in mice. (Atherosclerosis refers to a hardening of the arteries.) Researchers fed mice 40 mg/kg of the food additive every day for 4 months, and found that it not only altered gut microbiota but also led to a significantly increased atherosclerotic lesion area, especially in animals that consumed a high-choline western diet (HCD).

In summary, although more human evidence is needed to determine the risks of the mineral, potential titanium dioxide side effects from excessive exposure (especially when inhaled) may include:

Ultimately, most experts advise moderation, as titanium dioxide is typically found in processed foods that come with their own health risks.

In a small study published in the European Journal of Nutrition in 2020, researchers examined the effects of several food additives, including titanium dioxide, along with artificial sweeteners and cleaning products by testing the fecal samples of 13 people. Titanium dioxide was among the samples that “induced significant shifts in microbiome community structure.”  The growth of the bacterium species belonging to C. leptum, which has been shown to decrease in patients with inflammatory bowel disease, “significantly decreased in the presence of … titanium dioxide” among other additives and sweeteners tested.