Are Biotech Foods Safe?

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For thousands of years, crop improvement meant merely selecting seeds from plants with the largest, tastiest, or most robust offspring for propagation. Then, at the turn of the 20th Century, a growing knowledge of genetics and Mendelian principles of inheritance yielded a more systematic approach to genetic improvement.

Hybridization allowed breeders to assimilate desirable traits from several varieties of a single species into elite cultivars. But, while most laymen believe selection and simple hybridization were the only methods available to plant breeders until the introduction of recombinant DNA in the 1970s, nothing could be further from the truth.

Various methods of manipulating seeds and young plants in a laboratory environment can be employed to produce “wide crosses” between two plants of different species or genera that are otherwise sexually incompatible. Wide crossing, for example is often used to mate wheat or rye with various wild grasses in order to introduce a natural resistance or more robust growth from the wild plant to the cultivated one.

Like narrow crosses, the process randomly combines tens of thousands of genes from the two parent plants and commonly transfers thousands of uncharacterized substances from wild plants into food crop varieties. The addition or deletion of any one gene, or combinations of several new and old genes, could introduce a toxin or allergen, reduce the nutritional equivalency of the crop, or add weedy or invasive characteristics to the new variety.

Natural reproduction is also complicated by the presence of bits of DNA called transposable elements that “jump” into and out of various sites in a plant’s genome during normal cell division. These transposable elements insert themselves into and between genes, and are known to alter the expression of endogenous genes and serve as sites of chromosome breakage or rearrangement. But, they too can be effectively managed with standard testing.

Conventional plant breeders also commonly create entirely new genetic variants by intentionally mutating plants with x-ray or gamma radiation, with mutagenic chemicals, or simply by culturing clumps of cells in a Petri dish. This “mutation breeding” has been in common use since the 1950s, and more than 2,250 known mutant varieties have been bred in at least 50 countries, including France, Germany, Italy, the United Kingdom, and the United States. In mutation breeding, just as in sexual reproduction, breeders have no knowledge of the exact genetic changes that produce the useful traits or what other mutations may have also occurred – including those that could alter the ability to cause allergic reactions, over-express a natural toxicant or antinutrient, or generate other undesirable changes.  Ironically, this hugely unpredictable method is considered to be a type of conventional breeding, so its widespread and unregulated use is wholly uncontroversial.

Compared with these largely random, hit-or-miss methods of conventional plant breeding, recombinant DNA is far more precise and predictable, and its products are therefore more likely to be safe for consumers and the environment. Although modern biotechnology expands the range of new traits that can be added to crop plants, it also ensures that more will be known about those traits, and that the behavior of the modified plants will be easier to predict.