Dunkin' Donuts strips munchkins of their nanoparticles

For a limited time only, Dunkin’ Donuts customers can order their sugary breakfast treats sprinkled with candies, glazed with chocolate, or dusted with titanium dioxide.

Under pressure from the public interest group As You Sow, the company has agreed to stop using the whitening agent used in its powdered sugar donuts. Independent laboratory tests, commissioned by As You Sow in 2013, showed the powdered sugar used by the company contains titanium dioxide nanoparticles, substances engineered to have extremely small dimensions and frequently used in food, paper, paint, and sunscreen.

As You Sow claims the nanoparticles may result in toxicity for human health and the environment. “Preliminary studies show that nanomaterials can cause DNA and chromosomal damage, organ damage, inflammation, brain damage, and genital malformations, among other harms,” the interest group said in a statement.

But Andrew Maynard, director of the University of Michigan’s Risk Science Center, is not so sure the scientific evidence justifies pressuring Dunkin’ Donuts to make such a move. Titanium dioxide doesn’t appear to cause adverse health problems, he toldThe Conversation, it just makes foods look better. It’s the reason the powdered sugar coating on donuts appears so dense and snow white.

The U.S. Food and Drug Administration allows food to contain up to 1 percent of food-grade titanium dioxide without requiring it to appear on the label. Anyone who has eaten a slice of bread, a bar of chocolate, or a spoonful of mayonnaise likely has eaten a small amount of the chemical, according to Maynard.

As nanoparticles get smaller, their potential for harm grows. Some studies have shown nanoparticles smaller that 100 nanometers, about one 1/1000 the width of a human hair, can get into various cells in the body and cause unexpected harm. But the type of titanium dioxide typically used in food contains particles twice that size.

The science of nanoparticles isn’t as straightforward as it seems, Maynard said. There is little evidence the small quantities of nanoparticles found in food grade titanium dioxide pose a safety risk. A 2004 European Food Agency safety review panel found no evidence for safety concerns.

Most research on titanium dioxide involves the effects of nanoparticles that are inhaled in much larger concentrations than most people are likely to encounter, Maynard said.

“And while eating a powdered sugar donut can certainly be messy, it’s highly unlikely that you’re going to end up stuck in a cloud of titanium dioxide-tinted powdered sugar coating,” he quipped.

Researchers are only beginning to study the effects of ingested nanoparticles, but so far studies indicate the gastrointestinal tract handles small quantities of these particles without difficulty, according to Maynard. There is even some evidence nanoparticles occur naturally in the digestive system.

Other studies show no effects, indicating considerable uncertainty remains over the toxicity of the material. The broader issue lies in questions of how food companies should respond to inconsistent and conflicting scientific research.

“When there’s uncertainty around the science, how can food companies make smart decisions that don’t come back to bite them, either in the board room or in the court of public opinion?” Maynard said.