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Genetically Modified Foods: What We Know and Don’t Know
Advances in biotechnology have produced genetically modified crops that can be grown more economically. Over recent years, an increasingly larger proportion of our food has become genetically modified. While many experts believe this food is safe, many other experts argue that we have not yet studied all the potential consequences of producing and eating genetically modified foods. Are genetically modified plants safe for the environment? Are they safe for adults and children to eat? These questions elicit strong differences of opinion, and the bottom line is that we don’t yet know all the answers. Here is some basic information about what we know and don’t know about genetically modified foods.

What are genetically modified foods?
Genetically modified or genetically engineered foods have been produced by new recombinant DNA technology that inserts different genes into a plant in order to create a desirable trait. This technology has been used to increase the yield of crops by making them resistant to insects that harm them and to herbicides used to kill weeds. In addition, plants have been genetically modified to increase their nutritional value. For example, “golden rice” has been developed with increased levels of vitamin A to help fight vitamin A deficiency, which is a serious health problem in the developing world. Research is also being done to insert genes for vaccines into foods, so that an entire population could be immunized through the food supply.

Genetically modified crops have already been planted widely in the United States, and they comprise a substantial proportion of the food we eat. Approximately one-quarter of corn and one-half of soybeans in the U.S. are genetically modified. Experts state that as much as 60% of all processed foods in the U.S. contain genetically modified products. A much lower percentage of fresh produce is genetically modified.

Are genetically modified foods safe?
Genetic modification of foods has both potential benefits and potential risks for our health and for the environment. The biotechnology and agricultural industries, the Food and Drug Administration (FDA), and many respected scientists state that genetically modified foods are safe and “substantially equivalent” to non-modified foods. They point out that we have been eating genetically modified food for years with no evidence of serious problems. However, many other respected scientists state that there are too many unknowns, and that studies have not been done on the impact of genetically modified foods on humans, other species and the environment.

Currently, the FDA does not require safety testing or labeling of genetically modified foods.

The discussion of the potential risks of genetically modified foods focuses on the following areas:

There was a case in which genetically modified soybeans, modified with genes from Brazil nuts, were found to cause serious allergic reactions in people with nut allergies. In this case, the gene that was transferred from the Brazil nut caused the genetically modified soybean to produce the nut allergen. Without knowing that Brazil nut genes were in the soybeans, people with nut allergies would assume that the soybeans (and any processed food made with the soybeans) were safe, and they would be at risk for serious allergic reactions. As a result, the FDA’s current policy requires food labels to state when a product includes a gene from one of the common allergy-causing foods, unless the manufacturer can show that the protein produced by the added gene does not make the food cause allergies.

Antibiotic resistance:
Genes for antibiotic resistance are commonly inserted in genetically modified products as “marker genes” to help trace the movement of the desired gene. The concern is that animals or humans that consume the genetically modified product may acquire antibiotic resistance and spread it to bacteria living on and in our bodies, which might cause infections that are untreatable with antibiotics. The FDA, World Health Organization, and the European Commission Scientific Committee for Food and Animal Nutrition state that the risk of this occurring is low. Nonetheless, the law requires that antibiotic-resistant genes used as markers come from antibiotics that are “not clinically significant” to animals or humans. In the “Flavr Savr tomato,” for example, neomycin and kanamycin resistant genes are used—this is considered acceptable because these antibiotics are not widely used in humans and animals.

Increase in toxicity:
Genetic modification of plants to make them toxic to harmful insects could make them toxic to other non-harmful insects, wildlife and humans. Because genetic modification changes plants’ protein production in ways that are not entirely predictable, some scientists worry that toxins present in very low levels in many plants may increase, and this problem needs further study.

Spread of modified genes to the environment:
There is some concern about the spread of genetically modified pollen into the environment with unintended consequences. For example, many corn and soy plants are modified to be resistant to herbicides so that the fields can be sprayed for weeds and the crops will not be harmed. If the gene that makes the corn or soy resistant were to be transferred to the weeds, this could create a super-weed that would require greater concentrations or more toxic herbicides to control. These chemicals could also be dangerous to the environment and humans.

How can we reduce the possible risks of genetically modified foods?
Parents who are concerned about the unknowns may want to minimize the amount of genetically modified foods their family eats. This can be very challenging since a substantial proportion of the food in our markets—particularly processed foods—may be genetically modified. Furthermore, it is not easy to identify genetically modified foods since the United States does not currently require labeling, as Europe does. However, some organic food producers advertise that their food is free of genetically modified produce. If you wish to minimize genetically modified foods in your family’s diet, select organic produce and grain whenever possible, and serve your children more fresh/home-prepared foods and fewer processed foods.

If you have questions or concerns about genetically modified foods, contact your legislator.
Many communities are currently debating the need for safety precautions regarding genetically modified produce.

For more information and a discussion of the benefits and risks of genetically modified foods, visit the web site sponsored by the SCOPE Research Group which is a collaboration of University of California Berkeley, University of Washington and the American Association for the Advancement of Science: http://scope.educ.washington.edu.
Karen Sokal-Gutierrez M.D., M.P.H. Pediatrician