If genetically engineered foods aren't labeled as such, there's one way to know you're not eating suspicious DNA: The Certified Organic label.
"Unfortunately, consumers cannot avoid genetically engineered foods except by buying organic foods," says Ronnie Cummins, national director of the Campaign for Food Safety.
When the federal government considered allowing genetically engineered foods to be labeled as organic last year, more than 200,000 people -- from consumers to organic growers to chefs -- protested the move.
"You've got a bunch of giant chemical companies claiming that genetically engineered seeds are going to get the toxic chemicals out of agriculture, but that doesn't make sense," says Cummins.
It seems as though plants engineered to be pest-resistant would be useful to farmers wanting to avoid pesticides. But the problem lies in one of the main compounds being used. Bacillus thuringiensis, or Bt, is a natural pesticide organic growers sometimes spray on crops, where it breaks down quickly. But when it is incorporated into a plant's genetic makeup, it changes.
Studies show that the insects these plants repel could develop resistance to the pesticide in three to five years.
"Once Bt is ruined as a tool, organic farmers ... will have no tool, no choice but to get back on the chemical treadmill," says Cummins.
Currently, organic farming represents less than 2 percent of all agriculture in the United States, but the market for organic produce has been identified as one of the fastest-growing retail sectors.
More mainstream grocery stores now carry organic produce, and food companies are now using "all organic" as a marketing tool. And a few dairy products, such as Ben & Jerry's ice cream, label themselves as free from recombinant bovine growth hormone, a genetically engineered hormone currently given to at least 5 percent of U.S. dairy cows to increase their milk production.
Organic produce is currently more expensive than conventionally grown fruits and veggies, but Cummins predicts that as demand increases, supply will increase and prices will drop.
"Every time we pull out our wallets, every time we sit down to eat, we're casting our vote for certain kinds of food," he says.