You know the sugar in cereal is bad for you, but there's another ingredient that could be even worse: More than 40 percent of cereal could contain ochratoxin A (OTA), a potentially cancer-causing byproduct of mold, according to a new study just published in the American Chemical Society's Journal of Agricultural and Food Chemistry.
When researchers tested 489 samples of 114 corn-, rice-, wheat- and oat-based breakfast cereals (such as Corn Flakes, Rice Krispies, Total, and Cheerios, respectively) for OTA, 205 of the samples were contaminated—which amounts to a whole lot of bowls of cereal. Seventy percent of oat-based samples were contaminated, as were 32 percent of wheat-based, 15 percent of corn-based, and 15 percent of rice-based cereal samples. While the Food and Drug Administration doesn't regulate OTA in food, the European Union does. Sixteen samples contained unsafe levels of OTA, according to European guidelines.
Animal studies show OTA can cause kidney disease, breast and kidney tumors, and DNA damage, though more research is needed to figure out exactly how dangerous it is for humans. But the stuff is still considered carcinogenic, so this is scary news for cereal eaters. It doesn't help that cooking can't kill OTA, so oatmeal lovers: You're SOL too.
While the amount of OTA found in, say, one bowl of cereal, probably won't kill you, the study authors worry that OTA from cereal and other food sources—like wine and coffee, dried fruit, and pork—can accumulate in the body over time.
Until more research is done and the U.S. starts to regulate this byproduct, there's not much you can do to completely avoid it. In the meantime, you might considering cutting back on your favorite breakfast cereal—particularly if its main ingredient is oats. Yogurt, anyone?
This article originally appeared on Cosmopolitan.com. Minor edits have been made by the Cosmo.ph editors.