Biotechnology is usually thought of as increasing or introducing proteins via gene expression. This gene modification causes a change in or introduction of proteins within the plant. This same principle can be used for the removal or decreased expression of allergens (which are proteins) in foods. Some foods in the research phase of allergen removal or reduction are grains, rice and nuts. This topic is discussed in more detail in the Allergenicity lesson.
Fig. 1: Brazil Nut (University of Nebraska Lincoln. 2002)
Genetically engineered products
There are several future products that could have a positive impact on practice. First, for phenylketonuria (PKU) patients, biotechnology would make it possible to remove phenylalanine from wheat (1,5). This removal would open up a wider variety of foods for PKU patients to choose from. Next, microorganisms can be engineered to produce digestive enzymes. The microorganisms could in turn be colonized in the intestinal tract of patients with digestive enzyme insufficiencies (1,5). Another type of microorganism genetically modified to produce antibodies could be used to treat people with immune disorders (1,5). Finally, DuPont has over 40 clinical trials ongoing involving soy-based foods that lower cholesterol, combat osteoporosis and may help prevent cancer (10). Biotechnology has opened up many possibilities in the practice area of nutrition, and there are certainly more of these developments on the horizon.
Question: What type of beneficial food product would you create given the chance?
Biotechnology has been used for food safety applications in addition to the changes it has made in food products. Methods developed with biotechnology may help to decrease the amount of time needed to detect foodborne pathogens, toxins, and chemical contaminants, as well as detecting them with greater sensitivity (6). Some examples of these methods include enzymes, antibodies, and microorganisms used to monitor food production and processing for quality control (6). Biosensors could also be used to detect animal disease, alterations in product quality, or temperature abuse (6).
Fig. 2: (University of Nebraska Lincoln. 2002)
Products to treat diseases
One of the most exciting areas of biotechnology for practice applications is the use of this method to manufacture products for disease treatment. Some of these medicines are already available to treat diabetes, anemia, leukemia, cystic fibrosis, and growth deficiency (1,5). Albumin is even being produced using potatoes and protein recombination with microorganisms to address the shortage of this important blood component that is used in the treatment of severe burns, hepatitis and dehydration (8).
Vaccines are also being developed with biotechnology. One of the main advantages of biotech vaccines is that they contain only the antigen that helps the body build resistance. This contrasts to many vaccines that contain a weakened or killed form of the virus or bacteria. The other important advantage is the ease of delivery that food-based vaccines offer. These vaccines would not need to be kept refrigerated and no medical equipment would be needed for their administration. Less testing would also be required since there is less contamination with this method. This translates into lower-cost vaccines (Reuters Health, New York). For example, the current Hepatitis B vaccine costs about $450. Researchers are working on an edible vaccine that could be delivered via lettuce. The food that is used to produce the antibodies would be delivered via plant-based pills or capsules available only by prescription, which would keep them separate from the regular food supply (Reuters Health, New York).
What are some vaccines being studied? Probably the most well known is the development of a banana to deliver oral vaccines for diseases, such as Hepatitis B. An HIV vaccine using spinach has been successful in trials with mice and is still being studied (Reuters Health, New York). Spinach is also being used in the development of a rabies vaccine. There is currently not a vaccine available for rabies, so treatment occurs after a rabid animal bite.