The most popular Valentine gifts are flowers, chocolate, and candy. But just what lurks in those heart-shaped boxes of chocolates we’ve been indulging in? Researchers at Arizona State University warn that because children eat more candy than adults do, they may receive the highest exposure to nanoparticles of titanium dioxide, an ingredient commonly found in candy.

What is titanium dioxide?
Titanium dioxide is a common additive to many consumer products, ranging from food to cosmetics and personal care products to paint and adhesives. It’s used mainly as a whitening agent and as a pigment in paint.

What foods contain it?
For the first time researchers have analyzed how much titanium dioxide is found in food products and how much enters the environment. The top 20 foods that contain the most titanium dioxide include

  • gum
  • candy
  • cookies
  • marshmallows
  • pudding
  • cake frosting
  • coffee creamer

Researchers believe that children may receive the highest exposure to nanoparticles of titanium dioxide because children eat more of these foods than adults do.

What foods contain the least amount?
Researchers hypothesized that low-fat dairy products may contain high levels of titanium dioxide to improve their colour and texture. Interestingly, this was not the case. Ten of the 12 lowest ranked products were dairy products.

Similar products contained similar amounts of titanium dioxide. For example, different brands of chocolate syrup provided similar readings. Name brands and generic brands measured basically the same.

Chocolate products that contained a hard outer shell had higher concentrations of titanium dioxide. For example, a chocolate bar contained less titanium dioxide than M&Ms.

What does titanium dioxide do?
To be honest, no one really knows. Despite the fact that it’s added to so many food products, a lack of data prevents researchers from accurately determining its effects on health and the environment. 

Where does titanium dioxide end up?
Our bodies get rid of nanoparticles of titanium dioxide in urine and feces. However, the particles are so tiny that waste water treatment plants can’t filter them out, and they end up in rivers and lakes. Researchers caution that future research should focus on food-grade titanium dioxide as it’s much more likely to enter the environment where it may pose a health risk to humans and animals.