Bioengineered Foods and Allergic Reactions

By James H. Maryanski, Ph.D.

Have you heard that corn or tomatoes may have peanut genes or fish genes? You may be concerned that you or members of your family could be allergic to these new foods, especially if someone is allergic to peanuts or fish.

The Food and Drug Administration (FDA) has received many letters from consumers expressing concern about bioengineered foods. I would like to explain what bioengineered foods are, and how FDA is addressing questions regarding allergenicity.

Most fruits, vegetables, and cereals have been changed through plant breeding so that they bear little resemblance to their wild ancestors. Plant breeders have introduced disease resistance, increased yield, improved nutrition, and added many useful traits to crops to provide the safe and nutritious food supply that we take for granted.

Some foods result from crossing different crops: the tangelo is produced from tangerine and grapefruit; broccoflower is produced from broccoli and cauliflower. Until recently, all improved food crops were produced through imprecise, essentially trial and error methods.

Bioengineering or genetic engineering refers to new methods of plant breeding that permit scientists to improve food crops by introducing a copy of a gene for a specific trait (e.g., fruit softening). The gene can be copied from any organism (plant, animal, or microbe), thus providing plant breeders with a broader source of potentially useful genes and traits that would be available by conventional breeding methods.

To answer the numerous questions regarding bioengineered foods received from the industry and the public, the FDA issued comprehensive guidelines in 1992 to cover traditional and bioengineered fruits, vegetables, and grains. This guidance establishes a standard of care under the Federal Food, Drug, and Cosmetic Act to assist developers in evaluating the safety of new substances in foods (e.g., proteins), the nutritional content, the levels of native plant toxins, and the potential for allergenicity. FDA requires that bioengineered foods be as safe as other foods.

Allergenicity is an important consideration for bioengineered foods because there is some possibility that a new protein in a food could be an allergen. Developers must evaluate this possibility. This is especially true for genes derived from foods that commonly cause food allergy because they contain allergens. These foods include milk, eggs, fish, crustacea, mollusks, tree nuts, wheat, and legumes (particularly peanuts and soybeans). These foods account for ninety percent of food-allergic reactions.

Scientists report that only a fraction of the thousands of proteins in the diet have been found to be food allergens. Therefore, it is unlikely that most proteins introduced into food through bioengineering will be allergens. Additionally, scientists can determine whether a transferred protein has characteristics of known food allergens. To date, all new proteins in the bioengineered foods that will be sold in grocery stores have been shown to lack the characteristics of food allergens.

To alert sensitive consumers, FDA will require labeling for a food that contains a new protein with characteristics suggesting that it may be a food allergen. If we find that labeling will not adequately protect consumers, we will take steps to prevent marketing of the product.

We are following advances in bioengineering, and developers are working with FDA to ensure that safety questions are resolved. We are confident that the bioengineered foods that are currently approaching the market do not pose a safety concern for you or your family.

1. James H. Maryanski, Ph.D. is the Strategic Manager for Biotechnology at the FDA in Washington, DC.

2. Originally Published in Food Allergy News Volume Seven Number One October-November 1997

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