Researchers say lycopene also may offer health benefits due to its apparent antioxidant properties. These substances, which result from cell metabolism and other causes, may contribute to cancer and cardiovascular disease. Many genetic modifications have been designed to improve production. Most of these transgenic crop varieties have been designed to either better tolerate herbicides or resist insects without the need for extensive spraying of pesticides. An estimated two-thirds of the processed foods in U.S. supermarkets contain genetically engineered corn, soybeans or other crops.
Biotechnology also has the potential of creating major advances in medicine.
Scientists are looking into the possibility of producing bananas that contain vaccines against cholera, hepatitis B and diarrhea. Some researchers say that food-based vaccines could be especially useful in developing countries because the costs associated with refrigeration and needle sterilization would be greatly reduced or eliminated. In September 2000, a consumer group reported that a bioengineered variety of corn not approved for human consumption had been found in taco shells. The EPA approved Cry9C only for corn earmarked for animal feed and industrial uses. The agency did not approve the protein for human consumption due to lingering questions about Cry9C's potential to cause allergic reactions.