These include potatoes, tomatoes, soy, corn, squash and many other fruits and vegetables to which a variety of new genes from different species have been added. Labeling and testing are also vital given the health risks that scientists have associated with gene-altered foods. The most pressing health concern involves the impact of inserting novel genes into fruits, vegetables and other food products. With each gene insertion there is the possibility that a nontoxic element in the food could become toxic and create a human health hazard. This remains the most probable explanation for the dozens of deaths and hundreds of serious illness caused by the genetically engineered food supplement L-tryptophan several years ago.
Food allergies are another major health concern with genetically engineered foods.
Those with food allergies will have no way of knowing what foods to avoid. The problem of food allergies was outlined in a recent study reported in the New England Journal of Medicine. In the study a gene from a Brazil nut was introduced into a soybean. The genetically engineered soybean was then tested on people who were allergic to the nuts, and they had an allergic reaction to the engineered soybeans but not the natural variety. Health professionals are also concerned that the mass consumption of genetically engineered foods could make treating infections more difficult in that some genetically modified foods contain antibiotic resistant genes.