SAN FRANCISCO (KGO) -- More people are asking about what's in their food. So, how do you know what you're eating?
Yogurt maker Dannon recently announced it will only use milk from cows fed non-genetically modified foods. They are just one of many companies trying to get your attention.
Genetically modified foods make up 80 percent of what we eat, but you have no way of knowing that because the federal government doesn't require labeling.
Faced with a choice in the grocery aisle, many shoppers choose organic products. It sounds healthier.
Non-GMO Project, a non-profit based in Washington, came up with labels to inform consumers about genetically modified organisms.
"It means that, that product has been produced in the highest standards in the world for GMO avoidance," said Non-GMO Project's Megan Westgate.
GMOs are created in a lab with scientists using the DNA of one organism with another to yield what they consider a better result. For example, the FDA recently approved a genetically modified apple that won't brown when exposed to the air.
Only about a dozen genetically engineered crops have been approved for people to eat-- mostly corn and soy products and tomatoes. The crops are engineered to better resist pests and weed killers. The FDA says they are just as safe as non-GMO varieties.
Farmers worry that labeling non-GMO products could steer customers away from a booming organics market.
"By definition you can't have an organic pig, or organic cow, or organic chicken, or eggs unless it's fed organic feed," Tara Firma Farms' Kristian Eldridge-Squire told ABC7 News.
UC Davis Biologist Kent Bradford believes many of the foods advertised as non-GMO are misleading. "No, you really can't have a genetically modified egg. If there is no genetically modified variety of that particular species of chickens, or carrots, or whatever, then there's a question of whether you can say it's non-genetically modified because there is no option for it to be."
Experts say there's no conclusive evidence genetically modified organisms are harmful to humans. The one major study linking GMO's to cancer was later debunked.
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