A golden opportunity, squandered.

Even when used to make products of negligible risk and that contribute significantly to public health, recombinant DNA technology (a.k.a. ‘genetic modification’, or GM) applied to agriculture has a tough row to hoe. ‘Golden Rice’, which has been enriched by the addition of genes that allow rice to synthesize b-carotene (the precursor of vitamin A) in its edible endosperm, has endured resistance from activists and a decade of imposing and gratuitous obstacles to regulatory approval. This is an ominous precedent for other ‘biofortified’ foods made with recombinant DNA technology. The announcement in November 2008 by a group of multi-national European scientists that they had produced an extraordinary new, recombinant DNA-modified tomato variety garnered a great deal of media attention worldwide. This variety, which contains two snapdragon transcription factors, boasts deep purple skin and flesh and contains levels of antioxidants threefold greater than its unmodified parent. Most important, when fed to highly cancer-susceptible mice, the tomatoes significantly extended the life span of the animals [1]. These tomatoes are a so-called functional food, one fortified or enhanced with something that confers health benefits. This is not a new idea: for more than 80 years, iodine has been added to table salt to prevent hypothyroidism and goiter (see http://www.iccidd.org/pages/protectingchildren/fortifying-salt/history-of-salt-iodization.php). Newer functional foods, including eggswith enhanced levels of omega-3 fatty acids to reduce the incidence of heart disease and probiotic yogurt with extra bacteria to aid digestion, are becoming more common. The announcement of the enhanced-antioxidant tomato received wide attention from the press and scientific community, but an equally momentous achievement of plant genetic modification that is almost a decade old has been largely ignored. That innovation is ‘Golden Rice’, a collection of new rice varieties biofortified, or enriched, by the introduction of genes that enable the edible endosperm of rice to produce b-carotene, the precursor of vitamin A (see http://www.goldenrice.org). (It is converted in the human body, as needed, to the active form.) Why are these new varieties so important? After all, most physicians in North America and Europe never see a single case of vitamin A deficiency in their professional lifetimes. The situation is very different in many developing countries, however. Vitamin A deficiency is epidemic among poor people whose diet is comprised largely of rice (which contains neither b-carotene nor vitamin A) or other carbohydrate-rich, vitamin-poor sources of calories. In developing countries, 200–300 million children of preschool age are at risk of vitaminAdeficiency, which can bedevastating and even fatal. It increases susceptibility to common childhood infections such as measles and diarrheal diseases and is the single most important cause of childhood blindness in developing countries. Every year, 500 000 children become blind as a result of vitamin A deficiency and 70% die within a year of losing their sight (see http://www.cdc.gov/nccdphp/dnpa/immpact/ micronutrient_facts.htm). Why not simply supplement children’s diets with vitaminA in capsules or add it to some staple foodstuff, theway that we add iodine to table salt? It’s a good idea in theory, except that neither the resources – hundreds of millions of dollars annually – nor the infrastructure for distribution are available. Recombinant DNA technology offers a cheaper and more feasible solution: Golden Rice, which, after the insertion of two genes coding for phytoene synthase (psy) and phytoene desaturase (crt I), is able to accumulate b-carotene in the endosperm, the edible portion of the genetically altered rice grains (see http://www.goldenrice.org/Content2-How/ how1_sci.html). The concept is simple: although rice plants do not normally synthesize b-carotene in the endosperm because of the absence of two necessary enzymes of the biosynthetic pathway, they domake it in the green portions of theplant.Byusing recombinantDNAtechniques to insert the two genes that express these enzymes, the pathway becomes functional and the rice grains accumulate therapeutic amounts of b-carotene. Golden Rice and the enhanced-antioxidant tomatoes are examples of what has been called the ‘second generation’ of plants developed with recombinant DNA technology – those that provide consumer-directed benefits, as opposed to plants that offer only improvements in agronomic properties. GoldenRice offers the potential tomake contributions to human health and welfare as historic as those made by the discovery and distribution of the Salk polio vaccine. With wide use, it could save hundreds of thousands of lives a year and enhance the quality of life for millions more. But one aspect of this shining story is tarnished. Intransigent opposition by anti-science, anti-technology activists – Greenpeace, Friends of the Earth and a few other radical groups – has provided already risk-averse regulators political ‘cover’ to adopt an overly precautionary approach that has stalled approvals. There is absolutely nothing about Golden Rice that should require endless case-by-case reviews and bureaucratic dithering. As the journal Nature editorialized in 1992, a broad scientific consensus holds that ‘the same physical and biological laws govern the response of organUpdate