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the genetically engineered food would lack important nutrients that are normally present in the corresponding, natural, non-genet- ically-engineered food. pated, long-term or subtle effects that might not be immediately obvious, but that could be damaging to the species or to the quali- ty of the food that it produces. Nature is parsimonious, thus it is likely that these sequences have important functions, even though we do not presently know what those functions might be. Therefore, we should not assume that insertions into these sequences will be harmless. eS ors 2. Genetic engineering can create dangerous foods by we do not presently know what those functions might be. generating mutations in the DNA of the food-producing Therefore, we should not assume that insertions into these organism. sequences will be harmless. Inserting a recombinant gene into the DNA of a food-producing organism disrupts the natural sequence of genetic information 3. The damaging effects of genetic engineering cannot be within that DNA. Thus, the process of genetic engineering causes _ predicted or controlled. mutations to the food-producing organism. These mutations are a The ability of genetic engineering to introduce unanticipated second source of potentially damaging effects of genetic engineer- health hazards into foods derives from the fact that, although ing. genetic engineers can cut and splice DNA molecules with base- The location at which these mutations occur will be random pair precision in the test tube, when an altered DNA molecule is because, by and large, genetic engineers cannot control the site at introduced into the genome of a living organism, the full range of which a recombinant gene is inserted into the DNA of the organ- its effects on the functioning of that organism cannot be con- ism. They can cut and splice genes in the test tube with consider- trolled or predicted. able precision, but the process of inserting those recombinant What this means is that, in addition to the changes in biological genes into the host is very imprecise. function intended by the genetic engineer, the introduced DNA Many parts of an organism's DNA do not contain genes. may bring about other, unintended changes, some of which may Therefore, inserting a recombinant alter the properties of the food pro- gene into such a location will not dis- duced by the organism in a manner rupt any of the genes of the organism, . that makes it damaging to health. and, according to what molecular biol- Proponents of biotechnology Although the potential health haz- ogists know today, such insertions argue that the risk associated ards of genetically engineered foods should not cause any harm. However, are not different from those associat- it is just as likely that the recombinant | With genetically engineered foods § ed with other foods (namely, aller- gene will be accidentally inserted into is very small However. there is gens, toxins and reduced nutritional a 3 the middle of one of the genes of the value), the process of genetic engi- organism. This will disrupt that gene, | NO scientific evidence that this is neering itself is responsible for gener- and the organism will no longer be the case ating these dangers; that is, the use of able to produce the protein for which . the genetic engineering process intro- that gene is the blueprint. duces hazards into the resultant food. That gene may be the blueprint for Thus, the use of genetic engineering an enzyme that is important in cellular in the development of a new food- metabolism. Disrupting that gene could alter cellular metabolism, producing organism constitutes, in itself, a valid regulatory trig- possibly causing the organism to produce a toxic compound that ger. Stated in another way, because there is a distinct class of risk accumulates in the food produced by the organism. Disrupting that is directly and uniformly associated with the process by metabolism could also prevent the organism from producing cer- which genetically engineered foods are produced, that pro tain vitamins or nutrients, therefore reducing the nutritional value genetic engineering—can be used as a reliable flag for identifying of the food. foods that should undergo safety testing. Another possibility is that a genetically engineered gene might Proponents of biotechnology argue that the risk associated with be inserted into the DNA very close to an important gene of the genetically engineered foods is very small. However, there is no food-producing organism, thereby altering the expression of that scientific evidence that this is the case. If one holds to the stan- gene. For instance, it could cause the food-producing organism to dards of the science of risk assessment, the existing body of data produce ten times more or ten times less of that protein. This allows one only to state that, for a given genetically engineered could cause a variety of problems. First, a protein that is not toxic food, the risk is finite but of unpredictable magnitude. A real risk, or allergenic, when present at normal levels, might become toxic especially one of unpredictable probability and severity, is some- or allergenic if present at ten times higher levels. Second, if an thing that requires testing. important enzyme is produced at a level ten times higher or ten To support the contention that risks are small, proponents times lower than normal, this could drastically alter cellular attempt to infer the safety of future transgenic foods from the metabolism, leading to the production of a toxin or an allergen or roperties of genetically engineered foods now on the market. to the inability to produce an important nutrient. Third, if the However, this is also not consistent with established principles of gene encodes a peptide hormone, producing it at higher or lower the science of risk assessment. Furthermore, even if such compar- levels could disrupt important physiological processes, again lead- isons were valid, the handful of examples now available do not ing to changes in food quality or safety. rovide a sufficient database for such estimates. The diversity of There is a final problem that could result from mutations caused possible genetic manipulations that could be carried out in the by genetic engineering. As mentioned above, the DNA of most future, and the diversity of food-producing and gene-source organisms contains long stretches that do not serve as genes. The organisms that could be employed in the genetic engineering of current view is that these sequences do not have important func- future foods, is extremely large. Current examples are simply not tions, since altering or deleting portions of them does not seem to representative of the range of possibilities that will emerge in the have striking effects on the organism. However, the possibility future. Thus, to assure safety, each genetically engineered food has not been eliminated that such insertions could have unantici- should be tested thoroughly before it is placed on the market. the case. 18 - NEXUS FEBRUARY - MARCH 1997