Genetic engineering of foods to reduce the risk of heart disease and cancer

Abstract

Gene manipulation techniques can be used to increase, decrease, or add specific proteins to the edible parts of transgenic crop plants. With some basic understanding of plant biosynthetic pathways, then, the targeting of genes encoding specific enzymes allows the direct modification of the biochemical composition of foods. At Calgene, we have engineered the chemical composition of canola vegetable oils. Transgenic canola which are otherwise exactly like regular canola plants produce seed with oils a) that are modified in average fatty acid carbon chain length, b) that are modified in content of saturated fatty acids (both lower and higher), or c) that contain structured lipids. In principle, although the gene target may not be obvious, the relative amount of lipids compared to other nutrients can be decreased or increased in foods like peanut or soybean. The oil content of some food products might be modified to enhance levels of medium chain triglycerides or to contain 'fish oil' fatty acids without the cost or olfactory disadvantages. On a broader scope, the amino acid composition of proteins in basic grains is being pursued by several groups. Specific vitamin contents such as Vitamin A or E might be enhanced in basic foodstuffs; type and content of fiber may eventually be manipulated. Specific components such as caffeine or phytic acid conceivably can be eliminated in the source plant, negating the need for processing steps that add cost and that lessen flavor and nutrition. Clearly, the biochemical compositions of foods is complex and varied. Moreover, tailoring foods to better meet our needs is an expensive and lengthy process. The best possible understanding of how nutrition promotes good health is necessary to direct and prioritize our efforts to improve plants as food sources. Custom tailoring the chemical composition of lipids and other food components is demonstrated. The range of possible applications is wide. How best do we use these tools to help prevent heart disease and cancer? Prevention is obviously the most cost-effective treatment. Incorporating a rational, science-based approach to disease prevention in the basic diet is ideally a very cost-effective means to reach a susceptible population with comparatively painless and effortless compliance. In fact, it appears clear that disease conditions other than heart disease and cancer may be specifically addressed via diet. These conditions include cystic fibrosis and other malabsorption problems, diabetes, and obesity. Currently, however, the organizations with the skills to execute 'designer foods' typically lack the nutritional expertise necessary to evaluate the health-related opportunities. Nutrition literature often appears controversial, sometimes characterized as 'fads.' We suggest that this situation calls for an integrated interdisciplinary approach to define targets, to execute proposed development projects and to evaluate the results in terms of real benefits.