Titanium dioxide in food and its effects on gut cells
What it found
In lab tests, titanium dioxide tiny particles can damage gut cells and cause oxidative stress, but human studies are limited.
The authors say more research is needed to know if these effects lead to harm in people.
What they found
Studies in people
Human absorption
In human volunteers, a small amount of titanium dioxide was absorbed into the bloodstream after being swallowed. It was also found in human liver and spleen after death, suggesting it can build up in the body.
Animal and lab studies
Damage to gut cells
In lab tests with human intestinal cells, titanium dioxide particles damaged the tiny finger-like projections on cells and weakened the barriers between cells. This could affect nutrient absorption.
Oxidative stress
Many lab studies found that titanium dioxide caused an increase in harmful molecules called reactive oxygen species in intestinal cells. This can lead to cell damage.
DNA damage
Some lab tests showed that titanium dioxide could damage DNA in intestinal cells, which might increase cancer risk. But other studies did not find this effect.
Gut bacteria changes
In mice, titanium dioxide changed the balance of gut bacteria and the substances they produce. It also affected the mucus layer in the gut, which is important for protection.
Studies in people and animals
Inflammation
In both lab tests and animal studies, titanium dioxide triggered inflammation, with higher levels of inflammatory signals. In mice, it also affected immune cells in the gut.
What the authors conclude
- They conclude that titanium dioxide particles have the potential to cause DNA damage and chromosomal harm, but not gene mutations, and a concern for their ability to damage DNA cannot be ruled out.
- They advise that further research is needed to clarify whether titanium dioxide leads to harmful outcomes in humans and under what conditions, to ensure its safe use as a food additive.
How it was done
The authors wanted to understand how titanium dioxide nanomaterials, which are widely used in food, might affect the gut and cause health problems after being eaten.
They reviewed studies that looked at the effects of titanium dioxide on intestinal cells, mostly in lab tests, and some in animals. They also looked at how digestion might change the particles.
What it can’t tell you
- Most of the studies were done in cells or animals, so they cannot show what happens in people.
- The review cannot say whether the effects seen in lab tests lead to actual health problems in humans.
Who paid
- Authors work at
- National Institute of Health Dr. Ricardo Jorge (INSA), Portugal; ToxOmics - Centre for Toxicogenomics and Human Health, Portugal
The paper
- Title
- Cellular and Molecular Mechanisms of Toxicity of Ingested Titanium Dioxide Nanomaterials
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Evidence
- Studies in people · animals · lab
- Summarised from
- Full text
- Licence
- CC BY.
- Cite
- Vieira A, Gramacho A, Rolo D, Vital N, Silva MJ, Louro H (2022). Cellular and Molecular Mechanisms of Toxicity of Ingested Titanium Dioxide Nanomaterials. Advances in experimental medicine and biology. doi:10.1007/978-3-030-88071-2_10Free full textPubMed 35583647DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error