Fact Sheet about Food Safety Issues of Genetically Engineered (GE) Crops
Dr. Susan C. Miyasaka, Agronomist
Dr. Russell Nagata, Plant Breeder
“Foods consumed today are derived from plants and animals whose genetic makeup
has been modified by sexual crosses and mutation. Recombinant DNA provides a new
tool to make genetic modifications, and this technology is termed genetic engineering
or biotechnology. (Lemaux, 2008)”
“The safety of genetically engineered crops and foods, just as those created by classical
breeding and mutation and grown conventionally or organically, needs to be evaluated
on a case-by-case basis so that informed decisions can be made about their utility,
safety, and appropriateness. (Lemaux, 2008)”
What are the risks of eating transgenes? No negative effects on food safety have been found in
commercialized GE crops.
“To date, no scientifically valid demonstrations have shown that food safety issues of
foods containing genetically engineered (GE) ingredients are greater than those from
conventionally or organically produced foods. (Lemaux, 2008)”
“Extensive risk assessment and safety testing of crops developed through the use of genetic
engineering has shown that there are no varieties in use that pose risks to consumers. (Wieczorek
and Wright, 2012)”
“No reproducible data has shown that transgene DNA from commercialized GE crops behave
differently than native plant DNA. (Lemaux, 2008).”
“It was concluded that the transgenic soybean diet had no negative effect on fetal, postnatal,
pubertal or adult testicular development [of mice]. (Brake and Evenson, 2004)”
Do GE foods have changes in nutritional content? No substantial differences in nutritional content have been found between commercialized GE foods and non-GE foods.
Our data show that the contents of nutrients… of GE Rainbow papaya are within the range of
those of non-GE papaya and that the Rainbow cultivar is substantially similar to the non-GE
cultivar. (Tripathi and others, 2010)”
“The results [for Round-up Ready soybeans] demonstrated that the composition of these GE
lines is equivalent to that of conventional soybean cultivars in the form consumed by humans.
Have allergens been introduced through GE? No allergens have been introduced through
commercialized GE crops, due to extensive food safety tests conducted prior to approval by
“Although not mandatory, to date all companies marketing new GE foods have consulted with
the FDA and performed recommended analyses to determine if introduced proteins have
properties that indicate possible allergenicity, i.e., similarities to known allergens, small size,
slow digestibility, and/or high heat stability. (Lemaux, 2008)”
“Following accepted allergenicity assessment criteria, our results show that the transgenederived PRSV CP [Papaya Ring Spot Virus coat protein] does not pose a risk of food allergy.
(Fermin and others, 2011).”
“In recent years a variety of safety studies were conducted specifically on native Bt
proteins to show that they do not have characteristics of food allergens or toxins. (Lemaux,
Can GE foods fed to animals result in transfer of transgenes to animals? DNA and proteins are
broken down in the digestive tract. There is no scientific evidence to date that shows that
transgenes or their products are transferred to animals fed GE foods or excreted from
animals fed GE foods.
“To date a large number of experimental studies with livestock have shown that rDNA
[recombinant DNA] fragments or proteins derived from GM plants have not been detected in
tissues, fluids or edible products of farm animals(Lemaux, 2008).”
Can GE foods increase antibiotic resistance in human and animal intestinal flora? There is no
scientific evidence to date that GE foods can transfer antibiotic resistance to gut bacteria.
And current research now allows the removal of selection genes (antibiotic resistance
genes) or marker genes (gus gene) from GE plants.
“To demonstrate the fate of transgene DNA in humans, the antibiotic resistance gene from GE
maize was shown not to transfer to gut bacteria in chickens fed GE maize. (Lemaux, 2008)”
Why doesn’t the FDA require labeling of GE foods? The FDA does require labeling of GE
foods IF the product contains allergens and its source must be named.
“If a food contains a new, potentially allergy-causing introduced protein, the label must state that
the product contains the allergen and name its source. (Lemaux, 2008).”
Are there positive benefits of GE crops on food safety? Bt corn can be SAFER to eat than
non-GE corn, because of less damage due to corn earworms and lower infections of kernels
by fungi that contain mycotoxins.
“A positive aspect of safety regarding Bt corn is the lower levels of mycotoxins compared with
non-Bt corn. Mycotoxins are toxic and carcinogenic chemicals produced as secondary
metabolites of fungal colonization that occur as a result of insects such as the corn earworm
carrying the mycotoxin containing fungi that infest the kernels following wounding.” (Lemaux,
Brake, D.G. and D.P. Evenson. 2004. A generational study of glyphosate-tolerant soybeans on
mouse fetal, postnatal, pubertal and adult testicular development. Food and Chemical
Fermin, G., R.C. Keith, J.Y. Suzuki, S.A. Ferreira, D.A. Gaskill, K.Y. Pitz, R.M. Manshardt, D.
Gonsalves, and S. Tripathi. 2011. Allergenicity assessment of the Papaya Ringspot Virus coat
protein expressed in transgenic Rainbow papaya. J. Agr. Food Chem. 59:10006-10012.
Lemaux, P. 2008. Genetically engineered plants and foods: A scientist’s analysis of the issues
(Part I). Annu. Rev, Plant Biol. 59:771-812.
Tripathi, S., J.Y. Suzuki, J.B. Carr, G.T. McQuate, S.A. Ferreira, R.M. Manshardt, K.Y. Pitz,
M.M. Wall, and D. Gonsalves. 2011. Nutritional composition of Rainbow papaya, the first
commercialized transgenic fruit crop. J. Food Composition and Analysis. 24: 140-147.
Wieczorek, A . and M. Wright. 2012. History of Agricultural Biotechnology: How Crop
Development has Evolved. Nature Education Knowledge 3(10):9.