Have you been vaccinated against hepatitis? Has anyone you know had a heart attack and been saved by a clot-busting drug?
Genetic engineering has helped millions of people by turning gene-altered bacteria into microscopic factories that produce life-saving drugs. Nearly everyone welcomes those advances in medicine.
But corn flakes, salad dressing, and other foods that contain genetically engineered ingredients have gotten a decidedly cooler reception.
Using biotechnology to produce food has enormous potential: safer pesticides and less harm to wildlife, more nutritious foods, and greater yields to help feed the worlds hungry nations. Its the risks of dicing and splicing Mother Nature that are harder to get a handle on.
This month, we interview Doug Gurian-Sherman and Gregory Jaffe, co-directors of the Biotechnology Project at the Center for Science in the Public Interest, publisher of Nutrition Action Healthletter.
Q: What does it mean to genetically engineer something?
DGS: It means to remove genes from one organisma plant, animal, or microbeand transfer them to another. Most genes are simply codes, or blueprints, that tell a cell to make a protein.
So far, most genetically engineered food ingredients are made from plants. Theyre found in products like corn flakes made using genetically engineered corn, or salad dressing made with oil from genetically engineered soybeans. Gene-altered fish are in the works, while meat and poultry are years off.
Q: Why transfer genes from one plant or animal to another?
DGS: To give it some desirable trait. For example, a gene from a bacterium can enable corn and cotton plants to produce their own pesticide, one thats harmless to humans and to most insects that dont damage the crop. That allows farmers to use lessor less harmfulpesticides to get greater yields.
Q: How widespread are genetically engineered crops in the U.S.?
GJ: In 2001, over half of the cotton and soybean crops were genetically engineered. So was a quarter of our corn. Most of our corn and soybean crops are fed to animals, so the meat and poultry we eat is likely to come from animals raised on genetically engineered feed.
Q: Should we be nervous about eating food that contains genes from another organism?
GJ: No. In most cases, we arent eating those genes. For instance, by the time a genetically engineered corn plant has been processed into corn oil or high fructose corn syrup, virtually none of the genesor the proteins they produceare left in the food.
But even if a foodlike the cornmeal used to make many cerealsdoes contain new genes or proteins, thats not necessarily a problem. We eat foods with new genes and proteins all the time. The tomatoes, potatoes, and wheat we buy in the supermarket have been genetically altered by breeding them with wild relatives.
That kind of traditional cross-breeding, which weve been doing for decades, often produces foods that contain genes and proteins that people have never been exposed to before. And, like it or not, were constantly eating the genes and proteins of harmless bacteria that inadvertently end up on our food.
Q: But a gene from an animal would never end up in a corn plant naturally, because the two organisms are too different to breed.
GJ: Thats why we need to make sure that genetically engineered foods are safe before they reach the market. Its not inherently risky to mix genes from different organisms, but to play it safe, we should carefully test genetically engineered foods to ensure that they are safe.
Q: What should genetically engineered foods be tested for?
DGS: Whenever you put a new gene into a food, either through traditional breeding or genetic engineering, there are at least two major concerns. One is whether the new genes or proteins might produce toxinsthat is, anything that can cause harm in the short or long term. The other concern is whether the new gene might produce a protein that triggers an allergic reaction in a person who eats the food.
Q: Have new allergens ended up in a genetically engineered crop?
GJ: Yes. It happened when scientists unwittingly transferred an allergen from brazil nuts to soybean plants. But a routine test detected the allergen, and the soy was never marketed. That just underscores why its so important that the government require companies to test genetically engineered foods for new allergens.
Q: How good is that testing?
DGS: It could be better. Unless were dealing with known allergens, like the one in the brazil nut, theres no way to be absolutely sure if a protein will or wont trigger an allergic reaction until a lot of people eat it. What the Food and Drug Administration or Environmental Protection Agency should do is require companies to test every newly introduced protein to see if it resembles known food allergens.
Thats what happened with the infamous StarLink corn, which contains a gene taken from a bacterium. The gene produces a protein called Cry9C, which kills a major pest called the corn borer. So it looked promising to farmers. But because Cry9C passes through the digestive tract intact, it also looked like a potential allergen to the EPA, which approved its use only in animal feed. StarLink corn was never meant to be eaten by humans.
Q: So how did it get into taco shells and other foods?
GJ: Aventis, the company that created StarLink corn, didnt make sure that farmers and grain processors abided by government rules to keep StarLink separate from other strains of corn. As a result, tiny amounts of StarLink ended up in dozens of foods, and at least 44 people reported suffering possible allergic reactions after eating them.
Q: So a genetically engineered food has given us a new allergen?
DGS: Were not sure. When government scientists tested the blood of some of the people who reported allergic reactions, they couldnt detect any trace of a reaction to Cry9C. But those tests arent 100 percent reliable, so we dont know if the people reacted to Cry9C or not. In any case, the EPA has since decided that from now on it will only approve genetically engineered crops for animals that are also safe for people to eat. As for StarLink, its no longer being grown, so its rapidly disappearing from the food supply.
Q: Could genetically engineered foods be toxic?
DGS: Some could. When a gene is transferred from one organism to another, theres no way to know which chromosome the gene will end up on, where it will settle on that chromosome, or how it might alteror be altered bythe genes around it. We need to guard against unexpected toxins in genetically engineered plants because we know its happened with traditionally bred plants. Again, thats why these crops should be tested before we eat them.
Q: Are genetically engineered foods less nutritious than conventional foods?
DGS: No. They typically have the same amounts of vitamins, minerals, protein, and other major nutrients as conventional foods. Companies dont usually test for phytochemicals like lutein or lycopene because theyre not yet considered nutrients. But the FDA should consider changes in key phytochemicals when it decides whether to approve new foods.
Q: If a corn plant were engineered with a gene from a cow, could a vegetarian eat it in good conscience? Or could a steak from a cow that was given a gene from a pig be eaten by an observant Jew or Muslim?
GJ: Any genetic scientist would tell you that a corn plant with a gene from a cow hasnt been tainted by meat, and a cow with a gene from a pig hasnt been tainted by the pig. But when youre talking about religious or ethical beliefs, the science doesnt always rule. So Id say that those are decisions that every person has to make for him or herself.
Q: Are genetically engineered crops good or bad for the environment?
GJ: So far, theyre a plus. Last year, for example, thanks to genetically engineered cotton that produces its own insecticide, farmers reduced their use of highly toxic insecticides by several million pounds. Thats impressive, because the cotton crop has accounted for four out of every ten pounds of insecticides used in the U.S. each year.
And farmers who grow the most popular genetically engineered food crop, Monsantos Roundup Ready soybeans, spray their crops less often. So even if that doesnt reduce the amount of pesticides they apply, as some biotech critics have noted, theyre using a safer one. Roundup is much less toxic than many other herbicides. Farmers can also till the soil less often, which means less water pollution and soil erosion.
Q: What are Roundup Ready soybeans?
DGS: Theyre soybeans that are immune to glyphosate herbicides like Roundup. So when farmers spray Roundup Ready soybean plants with the herbicide, it kills weeds without harming the plants. The same gene has also been introduced into seed for corn, canola, and cotton.
Q: What other genes are being genetically engineered into crops?
GJ: One of the most popular is Bt, which is extracted from a bacterium called Bacillus thuringiensis. Organic farmers have been spraying Bt bacteria on their crops for years, because it produces a protein that poisons certain insect pests but is harmless to animals, people, and most other insects.
Scientists have transferred the gene that makes the insect-killing protein from Bt bacteria to corn, cotton, and potatoes. So those engineered plants can make their own environment-friendly pesticide, and farmers dont need to use as much chemical pesticides, which are far more indiscriminate killers.
Q: Is Bt in corn on the cob?
GJ: No. The sweet corn that ends up as corn on the cob or frozen or canned corn isnt genetically engineered. Nor are the soybeans that go into tofu and soymilk.
Q: Why arent they genetically engineered?
DGS: Because farmers are worried that consumers wont buy them. And thats unfortunate. In Florida, where much of the countrys sweet corn is grown, the crop is often sprayed with insecticides 10 or 12 times every season. Why? Because farmers know that shoppers wont buy corn on the cob if its been chewed by insects. They could probably cut their spraying down to twice a season if they planted Bt corn. Thats one of the lost benefits of biotechnology.
In addition, genetically engineered cropslike potatoes and sugar beetscould be grown with far less pesticides, soil erosion, and loss of innocent wildlife. But theyre not.
Q: Because companies worry that people wont buy them?
GJ: Thats right. Food manufacturers fear that some consumers wont buy foods made with genetically engineered ingredients. Potatoes are a great example. Scientists have genetically engineered some strains to kill insect pests and to resist two destructive viruses. But McDonalds wont buy genetically engineered potatoes because its afraid that biotech critics will mount a campaign against them.
Q: Could genetically engineered crops harm the environment?
DGS: Yes. Thats why the Environmental Protection Agency has to develop tests to ensure that they are safe. For example, in theory, the new genes in biotech crops could spread to other plants and create superweeds.
Heres the scenario. If pollen from an herbicide-resistant plant gets carried by the wind, it could pollinate a weed thats a relative of the plant. That could make the offspring weeds resistant to the herbicide. Or genes that make a plant resistant to insects or viruses could cross-breed into the wild relative, increasing its ability to survive.
Q: So we end up with more aggressive weeds?
DGS: Yes, though so far thats only a risk for squash and possibly canola, which are the only genetically engineered crops with wild relatives in the U.S. It could be a bigger problem if farmers started planting genetically engineered wheat, sunflower, sorghum, or other crops that have wild relatives. But scientists dont yet know whether those plants would become more aggressive weeds. To find out, we need more and better research.
Q: Can genetically engineered crops also become weeds?
GJ: Yes. Lets say some seeds from an herbicide-resistant crop remain in the soil after the harvest. If a farmer rotates crops, those seeds could grow into plants that are immune to the herbicides that the farmer uses on the new crop.
That seems to be happening with some genetically engineered herbicide-resistant canola plants in Canada, although it isnt clear if its a serious problem.
Q: Do genetically engineered plants kill Monarch butterflies?
DGS: Probably not. In 1999, a laboratory experiment showed that a heavy dose of pollen from Bt corn could kill caterpillars that develop into Monarch butterflies.
Since then, however, studies in fields in Iowa, Nebraska, Maryland, and Ontario have found that the plants dont produce pollen thats toxic enough to kill the caterpillars. And dont forget: conventional insecticides kill all kinds of insects, not just Monarchs.
Q: Can Bt or similar crops harm other good insects?
DGS: In theory, yes. Insects like ladybugs, which help protect crops by eating insect pests, could be harmed by eating genetically engineered plants or pollen or by eating insects that have fed on genetically engineered crops. In the laboratory, scientists have managed to harm a few beneficial insectsbut not birds or other animalsby feeding them high doses of Bt or insect pests that had eaten Bt.
But we wont know if its a problem in the real world until the EPA requires companies to conduct more field tests. Only then can we be confident that the crops are safe.
Q: Could insects become resistant to the Bt pesticide thats made by genetically engineered corn and other crops?
GJ: Eventually, insects can become resistant to almost any pesticide, genetically engineered or not. In the Philippines, for example, the Diamond- back moth became resistant to Bt due to conventional spraying, not to genetically engineered plants.
To prevent insects from becoming resistant, the EPA requires that farmers who grow genetically engineered Bt crops also plant conventional crops nearby as refuges where insects arent exposed to Bt. In theory, that should allow non-resistant insects to flourish, though no one knows how long the refuge strategy will work.
Q: So if were not careful, the use of Bt to replace more-toxic pesticides will be lost?
GJ: Thats right. Bt illustrates that the way we use biotechnology will determine how helpful it will ultimately be. Seed companies and many farmers want smaller refuges, because that means more genetically engineered seed sold and more crops grown. That may be good for profits in the short term. But if it meant that a relatively benign pesticide like Bt became worthless and farmers had to resort to far more damaging chemical pesticides, it could be disastrous in the long term.
Q: Does the same balancing act apply to other genetically engineered crops?
DGS: Yes. For example, aluminum-tolerant crops could allow farmers in developing nations to plant on marginal lands. But if farmers plant those crops in the aluminum-rich soil of tropical forests, well lose rain forest. And salt-tolerant tomatoes or a drought-tolerant crop could save precious water, but if theyre grown in semi-arid land that is currently not farmed, it could lead to further loss of natural habitats.
Q: Could genetically engineered crops somehow harm the soil?
DGS: In traditional agriculture, land can become less fertile over the years. Current biotech crops are likely to be safer for the soil.
But scientists have recently discovered that the Bt pesticide made by at least one type of genetically engineered corn seems to leak into the soil. A recent study found that it didnt harm earthworms or several other creatures that live below ground. But its just one more reason why the EPA must develop tests that crops have to pass before they can be marketed.
Q: Are organically grown crops better for people and the environment than genetically engineered crops?
GJ: Organic is often best, and the government needs to help farmers move from conventional agriculture to organic. But thats no reason to reject biotechnology, which can also protect the environment. Organic and biotech are improvements over conventional agriculture. We need research and support for both.
Q: How does the government regulate genetically engineered crops?
GJ: The U.S. Department of Agriculture is responsible for making sure that they dont harm other crops. If a crop makes its own pesticide, the EPA has to review the companys tests and approve the pesticide as safe for humans and the environment. And that process is open to the public. Other genetically engineered food plants are regulated by the FDA, which does not formally approve crops before they can be grown, harvested, and sold. It should.
Q: Does the FDA see any safety data?
GJ: The agency encourages companies to voluntarily submit test results, but doesnt tell them which tests to carry out. It needs to. So far, biotech firms have submitted some results for all of their genetically engineered crops, probably to cover their behinds. The FDA says that it plans to require companies to provide safety data, even though it still wont formally approve crops. While thats better than keeping the process voluntary, its not the best way to protect people.
Q: What should the government be doing?
DGS: First, before any genetically engineered plant or animal is grown in a way that can affect the environment, it should have to pass a thorough review by the EPA. Second, before any genetically engineered crops are turned into food, the FDA should have to formally approve them, as it currently does with genetically engineered animals. That means requiring companies to show that their crops are not toxic, dont contain any allergens, and dont pose other risks. Finally, the FDAs review of genetically engineered plants and animals should be open to the public, and the tests that it and the EPA require should be recommended by an independent organization like the National Academy of Sciences.
Q: Why dont labels disclose when foods contain genetically engineered ingredients?
GJ: Because they dont have to. The governments position is that it cant require labeling because genetic engineering per se doesnt make foods substantially different from their non-biotech counterparts. And if a food were differentfor example, if it had more unsaturated fat than usual then its label would have to disclose that difference, but not that the food was genetically engineered.
Nevertheless, the FDA needs to find a way to give consumers information about genetically engineered foods in an accurate, value-free way that doesnt raise the price of our food. It would be a shame to lose the benefits of biotechnology because of a backlash by consumers who feel that information is being hidden from them.
1. The genetically engineered foods that are currently on the market are safe. By increasing yields and reducing the use of pesticides, they benefit farmers and the environment.
2. To ensure that new genetically engineered plants and animals are safe for humans and the environment, Congress should institute a mandatory government approval process that is open to public participation and review.
3. The Environmental Protection Agency (EPA) should monitor the environmental impact of genetically engineered crops. It should require more field testing, enforce insect refuges for Bt crops, and adopt other environmental safeguards.
4. The U.S. government should fund more research on genetic engineering, especially on fruits, vegetables, and other crops that are not of great commercial interest to the biotechnology companies.
5. To enable developing nations to benefit from biotechnology, the U.S. government should: