Are Food Safety Studies Conducted on GE Foods?


GE foods and products made from GE crops that are used in foods today have undergone safety testing by the companies or institutions that developed them (see “Do Genetically Engineered Foods Have Changes in Nutritional Content?” and “Is the Bt Protein Safe for Human Consumption?”). The data were then reviewed by federal regulatory agencies. Frequently GE foods and products made from GE crops are also tested by outside groups and the results published in peer-reviewed journals. This process is comparable to safety assessments done for pharmaceutical drugs and biomarkers; pharmaceutical companies provide safety data that are subsequently reviewed by FDA scientists (1). Consultation with and submission to regulatory agencies of certain safety data for GE foods is voluntary, as are some data for pharmaceutical products (1); however, the legal requirements that foods (and pharmaceuticals) have to meet are not voluntary. Although GE foods can be marketed without certain regulatory approvals, to date all products in the marketplace have undergone full review by regulatory agencies regarding safety and content relative to unmodified forms (searchable data on specific events available at 2). Submitting the safety data is in the developer’s best interests, however, given the legal liabilities incurred should a problem with the food arise following market introduction (see “Can Genetically Engineered Food Crops Be Used to Make Pharmaceuticals? Could They Contaminate the Food Supply?”).

The EPA focuses on environmental and human health impacts of pesticides and therefore evaluates GE plants with altered pesticide traits. The EPA’s regulatory oversight of Bt crops is based on the presence in the plant of Cry proteins from B. thuringiensis (see “Is the Bt Protein Safe for Human Consumption?”), which are termed plantincorporated protectants (PIPs), substances that alter the crop’s pesticidal properties (3). Health safety assessments of GE foods are based in part on the concept of substantial equivalence (4). If the food and/or its new ingredient(s) is substantially equivalent to existing foods or food ingredients, it is treated like conventional foods with respect to certain aspects of its safety (5). Food or food ingredients used safely for long periods or foods substantially equivalent to these foods in nutritional characteristics do not require additional extensive safety testing. Substances that result in scientifically based safety issues require additional testing in the laboratory or in animal models.

A determination of substantial equivalence requires analysis of GE foods relative to comparable existing foods in terms of protein, fat, starch, amino acid, vitamin, mineral, and phytonutrient composition (6, 7, 8). GE foods can be designated substantially equivalent to their existing counterparts, substantially equivalent except for certain defined differences (on which safety assessments are then needed), or not substantially equivalent, meaning more safety testing and further review are necessary. When making such comparisons, it is important to note that the composition of components varies across a range—whether conventional, organic, or GE. For example, when polyphenol profiles of fresh apple juices from various apple (Malus domestica) cultivars and commercially available apple juices were compared, significant differences were found in total polyphenol content, as well as in profiles of individual polyphenols, as analyzed by high-performance liquid chromatography (HPLC)-photodiode array detection and HPLC-electrospray ionizationtandem mass spectrometry (9).

Large numbers of animal tests on GE foods and GE ingredients have been conducted and published in the literature (See 10, 11, 12, 13 and 14 for reviews). In the studies reported in these reviews, both chemical analyses and studies in a variety of animals (e.g., dairy cows, beef cattle, pigs, laying hens, broilers, fish, and rabbits) revealed no significant, unintended differences between GE and conventional varieties in composition, digestibility, or animal health and performance. The lack of significant differences between GE food and feed and isogenic counterparts in these tests strongly supports their substantial equivalence.

Food safety testing in animals is used to determine toxicity and allergenicity of the GE food or ingredient; however, such testing of whole GE foods and feeds is difficult or impossible owing to the need for animals to consume large amounts of food to obtain sufficient quantities of theGEingredient. Compositional analyses and toxicity testing of individual components are actually more sensitive and accurate in assessing safety (15). Therefore, in addition to whole foods, safety tests are conducted on individual products of introduced genes, both target and selectable marker genes, on the basis of the food additive provision (Section 409) of the 1992 Federal Food, Drug, and Cosmetic Act (16). This act states that substances intentionally added to food are food additives, unless they are GRAS or are exempt, as with a pesticide, and are then the responsibility of the EPA. GRAS status is established by a long history of food use or when the nature of the substance does not raise significant, scientifically based safety issues (17). For example, the FlavrSavrTM tomato (see “How Many Foods Are Genetically Engineered?”) was created using a kanamycin resistance selectable marker gene; data on the selection gene and its product were submitted by the company and, following review, the gene and its product were granted GRAS status (18).


1. Food Drug Adm. (FDA). 2005. Guidance for industry: Pharmacogenomic data submissions. Last accessed 2011-11-26. PDF

2. Food Drug Adm. Cent. Food Saf. Appl. Nutr. 2007. Biotechnology. Last accessed 2011-11-26. PDF

3. Environ. Prot. Agency Off. Sci. Coord. Policy Biotechnol. Team. 2006. Regulatory framework. Last accessed 2011-12-8. PDF

4. Kuiper HA, Kleter GA, Noteborn HPJM, Kok EJ. 2001. Assessment of the food safety issues related to genetically modified foods. Plant J. 27:503–28

5. Kessler DA, Taylor MR, Maryanski JH, Flamm EL, Kahl LS. 1992. The safety of foods developed by biotechnology. Science 256:1747–49

6. Berberich SA, Ream JE, Jackson TL,Wood R, Stipanovic R, et al. 1996. The composition of insect-protected cottonseed is equivalent to that of conventional cottonseed. J. Agric. Food Chem. 44:365–71

7. Sidhu RS, Hammond BG, Fuchs RL, Mutz J-N, Holden LR, et al. 2000. Glyphosatetolerant corn: The composition and feeding value of grain from glyphosate-tolerant corn is equivalent to that of conventional corn (Zea mays L.). J. Agric. Food Chem. 48:2305–12

8. Taylor NB, Fuchs RL, MacDonald J, Shariff AR, Padgette SR. 1999. Compositional analysis of glyphosate-tolerant soybeans treated with glyphosate. J. Agric. Food Chem. 47:4469–73

9. Kahle K, Kraus M, Richling E. 2005. Polyphenol profiles of apple juices. Mol. Nutr. Food Res. 49:797–806

10. Chassy B, Hlywka JJ, Kleter GA, Kok EJ, Kuiper HA, et al. 2004. Nutritional and safety assessments of foods and feeds nutritionally improved through biotechnology: An executive summary. Compr. Rev. Food Sci. Food Saf. 3:25–104
Provides scientific information and recommendations on safety and nutritional aspects of crops with improved nutritional qualities.

11. Flachowsky G, Aulrich K, Böhme H, Halle I. 2007. Studies on feeds from genetically modified plants (GMP)—Contributions to nutritional and safety assessment; Table 3. Anim. Feed Sci. Technol. 133:2–30

12. Konig A, Cockburn A, Crevel RWR, Debruyne E, Grafstroem R, et al. 2004. Assessment of the safety of foods derived from genetically modified (GM) crops. Food Chem. Toxicol. 42:1047–88
Provides guidance on how to assess the safety of foods derived from genetically engineered crops.

13. Preston C. 2005. Peer reviewed publications on safety of GM foods. AgBioWorld. Last accessed 2011-12-8. PDF
Extensive listing of peer-reviewed publications on food safety of genetically engineered foods.

14. van Eenennaam A. 2006. Genetic Engineering and Animal Agriculture. Univ. Calif. Agric. Nat. Resour., Agric. Biotechnol. Calif. Ser., Publ. 8184

15. Chassy B, Hlywka JJ, Kleter GA, Kok EJ, Kuiper HA, et al. 2004. Nutritional and safety assessments of foods and feeds nutritionally improved through biotechnology: An executive summary. Compr. Rev. Food Sci. Food Saf. 3:25–104.
Provides scientific information and recommendations on safety and nutritional aspects of crops with improved nutritional qualities.

16. Food Drug Adm. Cent. Food Saf. Appl. Nutr. 1996. Safety assurance of foods derived by modern biotechnology in the United States. Last accessed 2011-11-26. PDF

17. Food Drug Adm. (FDA). 1995. Generally recognized as safe (GRAS). Last accessed 2011-11-26. PDF

18. Redenbaugh K, Hiatt W, Martineau B, Kramer M, Sheehy R, et al. 1992. Safety Assessment of Genetically Engineered Fruits and Vegetables: A Case Study of the FLAVR SAVR Tomato. Boca Raton, FL: CRC Press. 267 pp.


Updated 2/16/12