FRIDAY, March 23, 2007 (HealthDay News) -- When you bite into an apple, you pretty much know what you're getting. The same can't be said for many packaged foods, which often contain ingredients that have been "genetically modified."
Corn and soybeans, along with cotton and canola, are among the most common genetically modified (GM) crops in the United States. According to the U.S. Department of Agriculture, an estimated 61 percent of the corn and 89 percent of the soybeans planted in 2006 were biotech varieties.
While the bulk of GM crops are destined to become animal feed, some of the bounty ends up in kitchens, restaurants and vending machines.
"Most of the processed foods that we eat -- cookies, chips, sodas, crackers -- all of those will contain some ingredients that are derived from corn or soybeans," said Michael Fernandez, executive director of the Pew Initiative on Food and Biotechnology, a nonpartisan source of information on agricultural biotechnology.
It's estimated, he added, that as much as 70 percent of processed foods contain an ingredient that has been genetically engineered. These ingredients include corn syrup, soy protein, canola oil, cottonseed oil and lecithin, a food additive derived from soy.
Genetically modified crops, first introduced for commercial production in 1996, take advantage of modern biotechnology. Scientists can select a desirable gene from one living organism and splice it into another. The gene for Bacillus thuringiensis, a toxin commonly used as an insecticide, for example, can be inserted into a plant to increase its resistance to diseases caused by insects. Other genetic modifications can boost a crop's resistance to a particular virus, say, or herbicide.
"They're now putting human genes into rice, for example, trying to produce pharmaceutical drugs," said Ronnie Cummins, national director of the Organic Consumers Association, an advocacy group of organic consumers and businesses. "They have put petunia genes into soybeans to make them [resist] a powerful herbicide," he added.
But could these combinations, which never occur spontaneously in nature, pose a threat to human health?
As a general rule, U.S. regulators, including the Food and Drug Administration, the Department of Agriculture and the Environmental Protection Agency, have found GM crops safe to grow and eat.
"These are products that have been consumed on a daily basis widely around the world for a number of years, so all evidence would suggest that the products that we have that are now on the market are safe to consume," Fernandez said.
But critics of GM foods argue that these reviews are not rigorous enough and fail to assess unintended consequences, especially health effects that arise over a longer period of time.
Cummins, a co-author of the book Genetically Engineered Food: A Self-Defense Guide for Consumers, says the major concerns are severe allergic reactions and damage to the immune system and digestive tract.
"The whole process of gene splicing -- haphazardly inserting foreign genes into common foods without really knowing what you're doing -- it's a hit-and-miss process," he contended. "Has this rearranged the genetic dynamics inside the cell to where you're producing more of a protein that will set off the allergies? Well, the bottom line is they don't know."
The possibility of allergic reactions is not without precedent. In 2000, the U.S. Centers for Disease Control and Prevention launched an investigation after consumers reported allergic reactions to a protein found in StarLink corn, a bioengineered variety of corn that ended up in the food supply. The incident sparked a mass recall of taco shells and other products containing the corn, approved for use in animal feed only.
So what can wary consumers do to avoid GM foods, considering there is no federal labeling requirement? The easiest thing to do is buy organic food, Cummins said, "because genetically modified organisms are banned in organic [foods], period."
Eating foods in their natural state and avoiding processed foods is also a good bet. "If you're eating a diet of whole foods and grains and beans and so on, you're going to be a lot healthier, anyway," he added.
More information
Learn more about genetically modified foods by visiting the U.S. Human Genome Program.
