You’ll probably recognize titanium dioxide as an ingredient in your makeup or sunscreen. It can be found in conventional products as well as “natural” products. According to EWG, titanium dioxide is used to make cosmetics more opaque as well as being a sunscreen. It even boasts a relatively low skin absorbency. But the question remains… is it safe?

Size Matters

By all accounts, titanium dioxide seems to be relatively harmless. However, there’s one overlooked factor in most safety reports: it’s size.

Nanoparticles are anything between 1 nm and 100 nm. NPs are 1 millionth of a millimeter. That’s 50 to 100,000 times smaller than a strand of hair! NPs can much more easily penetrate the skin because of their size. Titanium dioxide is typically used in the form of a nanoparticle (NP), which means it’s very, very small.

Danger of Nanoparticles

NPs are dangerous because of their ability to easily be absorbed by the body.  The exact repercussions of ingesting or absorbing NPs are unclear. However, several studies are raising concerns about titanium dioxide being linked to cancer or other diseases.

One study gave water with titanium dioxide to mice. After just 5 days, the mice had damage to their DNA and moderate inflammation.

Because of their size, NPs can easily move around in the body. Another study discovered an accumulation of titanium dioxide NPs in the brain. A toxicity study was done to reveal damage and death to mitochondria and astrocyte cells. Mitochondria supply energy to cells. Astrocyte cells help regulate neurotransmitters like serotonin and dopamine. In this study, the damaged astrocyte cells became unable to absorb glutamate. The glutamate was left to build up outside the cells. This effect has been linked to Parkinson’s and Alzheimer’s.

One study suggests that titanium dioxide NPs could penetrate the outer layer of skin depending on the skin type, age, and delivery. On the whole, even the NPs were not usually absorbed all the way through intact skin. However, damaged skin (cuts, sunburn, etc.) could potentially be more susceptible to absorption.

Shopping Titanium Dioxide Safely

Aside from cosmetics, titanium dioxide is used as a whitening and brightening additive in many popular products: candy, powdered sugar, toothpaste, and gum. Even things like bread, yogurt, and mayo can contain titanium dioxide.

The FDA allows up to 1% of titanium dioxide to be added to a product without listing it on the label.

Look for products, especially sunscreens, with non-nano titanium dioxide (or non-nano zinc oxide – the other popular sun protector). Both are better options than oxybenzone, a hormone-disrupting sunscreen ingredient. It’s nearly impossible to avoid buying cosmetics with titanium dioxide. Because it’s considered safe, even natural cosmetic companies have no problem adding it to their products.

Avoiding processed foods is a sure-fire way to keep titanium dioxide out of your diet. Consuming it through food is risky because there’s no easy way to find out whether the titanium dioxide used is nano-size. One study found that 36% of titanium dioxide in 90 products was NP size. However, you can be sure that Dunkin’ Donuts has ditched nano-form titanium dioxide from their products. (Although, there are plenty of other health reasons to keep your donut intake at a minimum!)