This week Dunkin’ Donuts announced that they were going to remove the titanium dioxide additive found in their donuts.
For many of us, this came as a surprise. Not that we were going to miss the titanium dioxide, but rather because we were wondering what titanium dioxide is, and what it is doing in our donuts in the first place.
What is titanium dioxide?
Titanium is a metal that is the 9th most abundant element in the Earth’s crust. the element is widely used in the manufacture of a variety of metal alloys. Titanium alloys are used in the shipping and aerospace industries due to their corrosion-resistance and strength.
Titanium dioxide (TiO2) naturally occurs in nature and is formed when titanium comes in contact with atmospheric oxygen.
What is titanium dioxide doing in our donuts?
Believe it or not, but more than just your donuts contain titanium dioxide. The compound is widely used in the food and cosmetic industries as a whitening agent. The bright white frosting of the donut, and the white coloring of toothpaste, is due to the use of titanium dioxide as a whitening agent.
Many sunscreen products contain titanium dioxide to make their products more opaque and block out ultraviolet radiation. The presence of titanium dioxide makes these compounds white in appearance. In an attempt to reduce the white residue common with sunscreens, manufacturers have reduced the size of the titanium dioxide particles.
Is titanium dioxide harmful?
Although Dunkin’ Donuts is removing the compound from their donuts due to pressure from a food safety group, there is little evidence that TiO2 causes any health risks. In fact, since titanium dioxide is inert (doesn’t readily interact with other compounds), the Food and Drug Adminstration (FDA) allows up to 1% of the contents of a product to be titanium dioxide without adding it to the ingredients label.
The concern is over what some are labeling as nanoscale particles (or nanoscale materials). Nanoscale particles are smaller than 100nm in size. If you are having a hard time visualizing a nanometer, then this RicochetScience video may help:
While there have been some concerns over the use of very small titanium dioxide particles in suncreens (typically in the 2-5 nm range), the fact is that there have been very few studies of the effects of these particles on human health. The concern from a variety of human health groups is that effects of titanium dioxide nanoparticles, and nonparticles in general, on the function of cells needs to be studied in more detail to ensure that they are safe. At the nano-level it may be possible for these compounds to enter the cell and influence cellular activities. There have been a few studies indicating that this may occur in mouse models.
However, those nanoscale-sized titanium dioxide particles are not used in the food industry. In fact, surveys of titanium dioxide in food indicate that the particles are not in the very small nanoscale range, and usually exceed 100 nm in diameter.
The conclusion? There is no doubt that there needs to more more studies on how nanoparticles, including TiO2, influence cellular activities. Since very small particles of titanium dioxide are not generally found in food products, including donuts, then there is probably not a major health concern. However, it is likely that the decision by Dunkin’ Donuts will probably cause other producers to remove the compound from their products.
Additional Resources
- Titanium dioxide resource page – ChemicalSafetyFacts.Org (American Chemical Society, 2015)
- Lost in Nano-translation: Titanium Dioxide in Food Products (Risk Science Center, June 2014). An excellent article that examines some of the problems of the health claims that titanium dioxide is a nanomaterial. Useful for discussions on the accuracy of information.
- Learn Science at Ricochet Science. A collection of videos that helps you understand some of the basic principles of science.
- Trouiller B., A. Westbrook, P. Solaimani & R. H. Schiestl (2009). Titanium Dioxide Nanoparticles Induce DNA Damage and Genetic Instability In vivo in Mice, Cancer Research, 69 (22) 8784-8789. DOI: http://dx.doi.org/10.1158/0008-5472.can-09-2496
- Weir A., Lars Fabricius, Kiril Hristovski & Natalie von Goetz (2012). Titanium Dioxide Nanoparticles in Food and Personal Care Products, Environmental Science , 46 (4) 2242-2250. DOI: http://dx.doi.org/10.1021/es204168d
Images:
- Donut: By Evan-Amos (Own work) [Public domain], via Wikimedia Commons
- Titanium dioxide: By Benjah-bmm27 (Own work) [Public domain], via Wikimedia Commons
