A new survey of 566 moms reveals a lack of understanding about Genetically Modified Organisms (GMOs) and 90% of moms would want GMO foods clearly labeled. The survey, commissioned by Nature’s Path, found that most moms (80%) feel confident they know what’s in the food they are putting on the table each day, and for seven in 10 that’s due to the detailed ingredient labeling on products. However, not every aspect of a food’s ingredients is shared—namely GMOs, also referred to as genetically engineered ingredients.

Close to half (45%) of mothers surveyed have never heard of genetically engineered ingredients. But once they learned about them, an overwhelming majority—nine out of 10 moms—said it’s important for brands to indicate whether such ingredients are used in their foods. GMOs are made from crops that have had their DNA modified with genes from other plants, animals, viruses or bacteria in a laboratory. They may be in up to 80% of the packaged food we eat, according to the Grocery Manufacturers’ Association, but there is presently no law requiring that they be labeled.

“We’re not sure how GMOs will affect our health because there haven’t been any long term studies to date,” said Arjan Stephens, executive vice president of sales and marketing at Nature’s Path. “That said, in 30 countries around the world there are significant restrictions or outright bans on GMO foods, because they’re not considered proven safe. This is cause for concern for many consumers, and why more and more are demanding labeling in the U.S.”

If brands were required to indicate whether genetically engineered ingredients were used to make their food, the survey found 38% of moms would consider switching to a brand that doesn’t include genetically engineered ingredients, and 33% might not feed that food to their family at all.