Just the mere mention of genetically engineered (GE) foods and genetically modified organisms (GMOs) today makes us think about science gone awry. The terms leave such a bad taste in our mouths that we often forget about the science behind it. What if nature has been modifying its genome for millennia before scientists accelerated the process? Are there species of plants we eat today that were developed from nature’s laboratory?
Nature uses gene guns to introduce genetic elements into plants as a means of introducing transformation. Plasmids from the bacterium Agrobacterium tumefaciens insert its DNA non-specifically (randomly) into a plant’s genome and cause the plant to produce bacterial food and express plant hormones. Overproduction of the plant hormones forces continuous growth of the transformed cells, resulting in a plant tumor. In the end, the plant benefits from the symabiotic relationship by rapid growth, and the bacterium benefits as more food is produced for its own growth. Depending on where the Ti plasmid from the bacterial integrates, if it inserts into a host plant gene expressing a nutrient, the host plant will fail to make that nutrient. These modifications or natural transformations have been going on since the beginning of time. These plants have the ability to propagate because of the innate ability of plant tissue in the form of a leaf to regenerate to a whole plant through the process of redifferentiation.
Today, gene guns have replaced older transformation methods like electroporation and Agrobacterium tumefaciens as the most common approach to transforming plants. Gene guns introduce micron-sized gold or tungsten bullets coated with DNA into the target host using helium gas for propulsion. Rice, the most important global crop because of the sheer number of people absolutely dependent upon its growth for consumption or export, is routinely transformed.
Lost in the discussion of GMOs and GE feeds is that humans have been modifying plant genes for thousands of years. Commercial crops of today bear little resemblance to their wild counterparts. Over the past 75 years, mutation breeding has been used to supplement conventional selection breeding methods to enhance the taste of fruit or resistance to disease. In 1943, the first mutant was reported for barley demonstrating a phenotypic resistance to mildew. Thousands of mutant cultivars have been created for the world food supply, mostly for cereals and legumes. The majority of cereal mutants were developed in the past 25 years for rice, bread wheat, and barley.
Have you ever tasted a rutabaga or a Rio Red grapefruit? Rutabaga, a phylogenetically new species in comparison to its ancestral DNA, was produced by nature as a cross between the turnip and cabbage, resulting in a doubling of its chromosome number. The Rio Red grapefruit was developed in the 1980s from a Texas breeding program through irradiation of budwood from a Ruby grapefruit seedling. How about seedless watermelons and seedless cucumbers? Seedless watermelons were developed over 50 years ago through hybridization techniques. While not genetically engineered, they are genetically modified in that normal diploid pollen is crossed with quadriploid flowers to produce the triploid (three times the genetic material) seedless, sterile watermelon species.
While the Food and Drug Administration has not defined GE or GMO, some groups have developed a standard definition. According to some organization standards, genetic engineering typically means that it is made with techniques that alter the molecular or cell biology of an organism by means that are not possible under natural conditions or processes; however, GE has traditionally not included breeding, conjugation, fermentation, hybridization, in-vitro fertilization and tissue culture as a means of manipulating genetic information in a cultivar. Therefore, seedless varieties are not GE but they are GMO. Consumers often cite loss of taste as to why GMO seedless watermelons are not acceptable. The same is not true for seedless cucumbers as the seeds are the reason why cucumbers taste bitter. The absence of bitterness with seedless cucumbers is a desirable GMO trait.
Can we avoid GE and GMO foods altogether? That is a nearly impossible task. In the U.S., the predominance of GE crops in the market is staggering. Corn, soybeans, cotton, canola, alfalfa, sugar beets, papaya and squash are all mostly GE. Genetically engineered Corn, sugar beets and soy make up greater than 90% of their respective markets in the U.S. Considering that most of the foods on store shelves contain some sort of soy or corn ingredient, it is difficult to avoid GE foods.
What are the issues surrounding disclosure of GE and GMO ingredients? It is more complicated than it seems. One question is deciding whether GE and GMO ingredient disclosure should be based upon testing for the presence of any GMO substance in the final ingredient or product or whether it should be based upon the process and the source ingredient. For instance, a vitamin could be made from a GMO-sourced ingredient, but the vitamin or mineral ingredient could be manufactured in its final form, free of any GMO contaminant or signature. Some point to the U.S. Department of Agriculture’s (USDA) organic standard as the best approach to dealing with the issue of GMO and GE foods until FDA provides clarity with definitions.
Interestingly, “organic” does not eliminate GMOs altogether. One can still label a food as organic and contain GMO ingredients in trace levels. Even authors of the organic standard realize that non-GMO cultivars can never really be 100% free of contamination by GMO and disease-resistant cultivars that were “blown” into a non-GMO harvest.
Due to these complexities and decisions that must be made regarding GMO ingredients, any legislation for labeling requirements should come from the federal government rather than individual states, if there is a requirement to label GMOs in products. The FDA and the USDA are the agencies anointed to enforce misbranding, an illegal act, and they should be the ones to enforce misbranding over GMO labeling in the future. The Natural Products Association (NPA) supports one over-arching labeling requirement and definition of GMO from the FDA, as it is difficult for firms to manage multiple state-sanctioned labeling requirements for GMO and GE foods.
While NPA, consumers, retailers and suppliers wait for the FDA to define GMO and natural, NPA would want data and lists from the FDA and the USDA regarding ingredients they believe to be GE or GM when defined. The ingredient lists and information those agencies collect from inspections should be able to provide insight as to the origins, manufacturing and processing of those ingredients. The list of generally known GE ingredients would be useful as a benchmark if there is a public health issue regarding use of particular GMO ingredients in products. NPA would like the FDA and the USDA to provide data on the science and public health of GMO ingredients. While many organizations have advocated for use of only non-GMO ingredients, the list of GMO ingredients from the FDA and the USDA might be staggering. Any moves to demand only non-GMO ingredients in foods on a grand scale would result in higher costs to the customer. I have yet to see a comprehensive economic analysis as to how such a change would impact customers to pay for food in the future. It might even lead to significant food shortages, an unacceptable cost to any society. WF
Corey Hilmas, M.D., Ph.D., is the Natural Product Association's Senior Vice President of Scientific and Regulatory Affairs. Dr. Hilmas oversees the development and implementation of all educational, scientific and compliance programs at NPA, and provides guidance on clinical issues, public health, ingredients and regulatory compliance. Dr. Hilmas is a medical doctor with a degree from the University of Maryland School of Medicine. He also holds a doctorate in pharmacology and toxicology. He joined NPA after having served as chief of the Dietary Supplement Regulation Implementation Branch within the Division of Dietary Supplement Programs at the U.S. Food and Drug Administration (FDA) for more than two years.