When you pour dressing on your salad, drink a soda or snack on potato chips, chances are you are ingesting genetically modified organisms without even knowing it. That's because such everyday ingredients as corn sweetener and vegetable oil are derived from genetically altered crops.
Does this affect your health?
Although consumer groups warn that splicing a gene from one organism into the DNA of another has the potential to produce toxins or allergens, the consensus in the scientific community is that genetically modified foods, at least for now, pose no threat to human health. On the contrary, scientists believe that such foods can eventually be engineered to be more nutritious and contain fewer harmful microbes as scientists learn more about the traits of individual plant genes.
“People may worry about the issues and risks of biotechnology, but on a scientific level, it's boring,” says Adrienne Massey, a biotechnology consultant in North Carolina.
“I have seen nothing that would indicate that genetically modified foods are a safety issue, and that has been supported by just about every national academy of science across the world,” agrees Judith A. Kjelstrom, assistant director of biotechnology at the University of California at Davis. “There has been no recall of a genetically modified crop based on someone becoming ill. It's like anything else new. People are just afraid of it.”
But some health-care advocates believe that the government is playing with fire by not insisting on more stringent safety tests. They point out that no one knows the types of proteins and other substances that could result from taking a gene from one organism and putting it inside another.
“This is a new technology. We have very little experience with it,” says Jane Rissler, senior staff scientist for the Union of Concerned Scientists. “It's dramatically different from conventional breeding. We believe the food should be subject to rigorous safety testing.”
The debate over the safety of genetically altered food has taken on new urgency since last year's revelations that genetically modified StarLink feed corn made its way into the food system, even though it was never approved for human consumption. The Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC) are investigating several dozen complaints of people who say they suffered severe allergic reactions after eating products, such as tortillas, that may have contained StarLink corn. The investigations are complicated because researchers may be unable to conclusively demonstrate the corn or something else caused the allergic reactions.
Keith Finger, a Florida optometrist who said he suffered a serious allergic reaction after eating tortillas, beans and rice in September, filed a report with the FDA and joined in a lawsuit against Aventis, the manufacturer of StarLink. “It's scary to think people might have reactions to something they don't even know is in their food,” he said. “This needs to get cleared up soon.”
Aventis, however, insists that StarLink could not have caused such allergic reactions, partly because potential allergens would have been destroyed in the food-manufacturing process. And some scientists contend that biotechnology, far from causing allergic reactions, has the potential to improve food safety, as researchers focus on creating non-allergenic foods.
“Biotechnology has the capability of taking away the gene that produces that allergy,” explains Les Crawford, director of food and nutrition policy studies at Georgetown University.
Now that genetically modified ingredients have made their way into an estimated two-thirds or so of processed food in the United States, several highly regarded scientific organizations are taking a close look at the potential effects on public health. Their almost unanimous verdict: The foods are safe, but government regulators should consider stepping up safety tests.
In 2000, the National Research Council, an arm of the Academy of Sciences, stated that it was “not aware of any evidence that foods on the market are unsafe to eat as a result of genetic modification.”
An American Medical Association committee also gave a thumbs-up. “From all the research that's been done and all the information we have to date, genetically altered foods appear to be quite safe,” said Roy Altman of Miami, who presented the report on behalf of the medical association's Council on Scientific Affairs.
Other respected organizations from the World Health Organization to Consumers Union also have affirmed the safety of the food.
At the same time, however, many scientists warn that the potential risks are worrisome enough for government regulators to test more carefully for allergens and toxins. Issuing an especially sharp warning, the prestigious Royal Society of Canada concluded in February that international standards for the testing of genetically modified foods are “scientifically unjustifiable.” The society criticized government regulators for presuming that the foods are safe, and warned that the biotechnology industry has too much sway over the regulatory process.
“The public interest in a regulatory system that is science-based is significantly compromised when that openness is negotiated away by regulators in exchange for cordial and supportive relationships with the industries being regulated,” the report stated.
The reason for such concerns: genetic engineers, while extraordinarily capable of isolating and transferring a single gene, have little control over where that gene will wind up in the target food. Random insertion, in other words, could activate or inactivate a nearby gene, leading to secondary effects.
In addition, the gene-splicing process involves the use of powerful chemicals, such as a viral promoter known as the Cauliflower Mosaic Virus. As a result, the cells in genetically changed foods can begin manufacturing new proteins, or they can produce existing proteins in such quantities as to cause a toxic reaction in humans.
The modified foods also have the potential to cause dangerous allergic reactions. This almost caused a health problem in the mid-1990s, when an agricultural company named Pioneer Hi-Bred (since bought by DuPont) was preparing to market soybeans that contained DNA from Brazil nuts. The company dropped its plans when University of Nebraska researchers reported that the soybeans could induce fatal reactions in people who were allergic to Brazil nuts.
Genetically engineered salmon and other fish, which may become commercially available within a couple of years, pose similar risks. Because some species of fish are known to contain toxins, advocates warn that an introduced gene may inadvertently “turn on” an inactive gene for the production of toxins in target fish.
Many in the scientific community believe that such fears are overblown. They point out that farmers have been cross-breeding plants for thousands of years, creating new types of plants that rarely threaten human health. If the risks are minimal from traditional cross-breeding, which involves the shuffling of thousands of genes, why worry about the splicing of a single gene?
“If we're going to assume that conventionally bred crops that appear with 10,000 new genes are safe, then it doesn't make sense to me as a scientist, rationally, that one crop that's been in the food supply has one new gene added, and you know everything about that gene, then that crop is a danger,” Massey says.
Other scientists agree. The National Research Council's 2000 report, for example, stated that the risks posed by genetically engineered crops are “the same in kind” as those posed by crops that are modified through conventional cross-breeding techniques.
But even conventionally bred crops are not without risks. In 1967, the Department of Agriculture unveiled the Lenape potato, which was bred for high solids content. Two years later, a Canadian plant breeder became ill after consuming the potatoes, which were found to contain high levels of solamine, a toxic organic substance. The potato, which was withdrawn from the market, remains an enduring example of the unexpected consequences of mixing plant genes.
In the case of genetically engineered foods, advocates are particularly concerned that the government relies on industry statements about the safety of the new organisms instead of conducting its own tests. “The present system assumes that there will never be human error and that human greed will never overcome good judgment,” says Carol Tucker Foreman, director of the Consumer Federation of America's Food Policy Institute. “That's a mistake.”
But Peter Day, director of Rutgers University's Biotechnology Center for Agriculture and the Environment, says consumers should have more faith in the biotechnology industry.
“I'm satisfied that major, responsible companies who are willing to undertake the costs of the research are sufficiently astute to protect their own interests to avoid being sued by people for any harm,” he says.