Is Titanium dioxide Safe for Hashimoto's Thyroiditis?
For people with Hashimoto's Thyroiditis, Titanium dioxide is worth limiting or using with caution both during a flare and in remission. Titanium dioxide (E171) is a white food-colour additive.
Status for Hashimoto's
Why this rating?
Titanium dioxide (E171) is a white food-colour additive. Research has raised concerns about possible effects on the intestinal lining, but evidence in people with autoimmune conditions remains limited.
People who are sensitive to this ingredient may notice gi. Individual responses vary, so this symptom category does not replace the condition-specific rating above.
Editorial summary
This summary is editorial and is not part of the clinical review. Ratings above are unchanged.
What titanium dioxide is
Titanium dioxide, also written TiO2 or E171, is a white pigment added to some foods to make them look whiter or brighter. In the United States, the FDA permits it as a color additive in food at up to 1 percent of the weight of the food under 21 CFR 73.575.
Why regulators disagree
In 2021 the European Food Safety Authority concluded that titanium dioxide can no longer be considered safe as a food additive because genotoxicity could not be ruled out, and the European Union removed it from its approved food additive list through Regulation (EU) 2022/63, with a transition period that ended in August 2022. In the United States, a color additive petition filed in April 2023 asks the FDA to repeal the food listing, citing the 2021 EFSA opinion and concerns about nano-sized particles. The FDA states that it is reviewing the petition, and the additive remains permitted while that review continues, so check the FDA's titanium dioxide page for the current status.
Why our rating says caution
Our rating note reflects research raising concerns about possible effects on the intestinal lining, and states that evidence in people with autoimmune conditions remains limited. Look for titanium dioxide, TiO2 or E171 in the ingredient list of candies, icings, coated products and processed foods.
How Titanium dioxide is rated across conditions
The same ingredient can mean different things depending on the condition. These are the ratings for every condition that has a guide for Titanium dioxide.
| Condition | During a flare | In remission |
|---|---|---|
| Inflammatory Bowel Disease (IBD) | Avoid | Limit / Caution |
| Hashimoto's Thyroiditis | Limit / Caution | Limit / Caution |
| Graves' Disease | Limit / Caution | Limit / Caution |
| Rheumatoid Arthritis (RA) | Limit / Caution | Limit / Caution |
| Multiple Sclerosis (MS) | Limit / Caution | Limit / Caution |
| Lupus (SLE) | Limit / Caution | Limit / Caution |
Also listed on labels as
Titanium dioxide can appear on an ingredient list as TiO2, E171.
Related ingredients
Same ingredient family or way of affecting the body.
Other conditions
Sources
Published sources
- Sarris, J., & Wardle, J. (Eds.). (2010). Clinical Naturopathy: An Evidence-Based Guide to Practice (1st ed.). Elsevier. ISBN 9780729539265. — literature
Clinical review
Reviewed by Morvarid Nikousokhantayar, MSc Nutrition, Certified Naturopath & Nutritionist — last reviewed September 25, 2026.
This is general dietary information, not medical advice. Talk to your care team about your individual triggers.
Want to check a full product against your conditions?
Scan a barcode with FoodSage to see Titanium dioxide and every other ingredient checked against Hashimoto's Thyroiditis and any second condition you set. Learn about FoodSage.
