Critics and supporters of genetically modified (GM) foods are duking it out again, as the FDA considers approving the first-ever genetically engineered animal food - in this case a breed of salmon modified to grow twice as fast as ordinary salmon.
Whatever the FDA's decision, food experts say many Americans are woefully misinformed about genetically engineered foods.
CBS News spoke with two prominent experts on GM foods to get their take on the potential risks and benefits of what some are calling "Frankenfoods."
You might think the FDA thoroughly tests genetically modified foods to make sure they are safe. In fact, the FDA doesn't test them at all.
Instead, says Consumer Union's Jean Halloran, it takes the word of the companies that develop the foods.
"When a company comes in with data, the FDA looks at it and writes a letter saying, "Dear Monsanto, you supplied information regarding the safety of corn variety X and we are confident about what you've shown," Halloran says. "It is your responsibility."
Monsanto is the world's largest developer of GM foods.
If you've been scanning food labels to check whether you're about to buy products containing GM foods, you're wasting your time.
The FDA decided more than a decade ago that GM foods do not have to be labeled. So there's no easy way to tell whether a particular packaged food is made with GM crops.
Genetically Modified Ingredients
Think your shopping cart is free of GM foods? Think again.
According to WebMD, only 26 percent of Americans believe they have eaten genetically modified foods.
The reality is almost all have. Up to 70 percent of food in the grocery store has some genetically modified material in it, says WebMD.
The most common staples are soy and corn. That means corn syrup sweetened sodas, cereals and snacks probably have genetically modified material in it.
When it comes to animal products, so far there aren't any genetically modified animals on the market - no pork, beef, chicken, etc.
Help Against Hunger?
"The industry often says that genetically modified foods are the most promising way to meet the food needs of the 21st Century," says Dr. Nestle. "This is an exaggeration."
Nestle says food shortages around the world are the result of poverty and other social problems that cannot be solved with a technological fix - a sentiment echoed by other food experts.
"In the U.S., we have had food surpluses for a decade, and yet we still have hunger," says Jean Halloran, director of food policy initiatives at Consumers Union, which publishes Consumer Reports. "It's not because we don't have enough genetically modified foods. Some people can't afford food at any price."
To date, there's no evidence that anyone has ever gotten sick from eating a genetically modified food," says Dr. Nestle. But, she says, there are theoretical risks - including the risk of allergic reactions.
Some people are allergic to fish, and Consumers Union - a vocal critic of GM foods - issued a statement saying that modified fish might be more likely than conventional salmon to cause severe, life-threatening allergies.
The GM industry disagrees. "I think what the science has proven is that there is not a link to allergenicity," says Karen Batra, a spokesperson for the Biotechnology Industry Organization, a Washington, D.C.-based trade organization.
Despite the absence of evidence for health risks associated with eating GM foods, Nestle remains wary. "I still have some lingering concerns about the safety of genetically modified foods," she says.
Restrictions in Europe
European consumers have been very slow to accept genetically modified foods and have placed much tighter regulations upon them than in the United States.
All products which contain a certain amount of genetically modified material must be labeled, making them less than popular.
"People don't want them," Dr. Nestle says.
And until recently, the European Union had a moratorium on growing GM crops in member countries.
Critics of genetically modified foods were ridiculed when they suggested several years ago that genes from genetically modified crops would start showing up in conventional crops. Well, no one is laughing any more.
Dr. Nestle points out that airborne pollen from a field of genetically modified corn or soybeans, for instance, can drift over to a field where conventional crops are planted - and spread altered genes.
Says Nestle, "They can't keep their genes under control. There is a 100 percent probability that modified genes will show up in other crops to some low percentage."
One of the early selling points of genetically modified food was that crops engineered to be resistant to pests would require less pesticide.
That's true for certain varieties. But most GM crops are designed to be resistant to the chemicals that kill weeds and bugs. That means farmers can use the herbicides more liberally without killing their plants.
That's good news for Monsanto, the company that makes most of the world's GM seeds as well as the herbicide used to spray the crops.