'Golden Rice' and Biofortification - Their Potential to Save Lives Is Being Hampered by Overzealous Regulation

摘要

Dietary micronutrient deficiencies, such as the lack of vitamin A, iodine, iron or zinc, are a major source of increased susceptibility to disease and mortality worldwide. These deficiencies affect particularly children, impairing their immune systems and normal development, causing disease and ultimately death. The best way to avoid micronutrient deficiencies is by way of a varied diet, rich in vegetables, fruits and animal products. The second best approach, especially for those who cannot afford a varied diet, is by way of nutrient-dense staple crops. Sweet potatoes, for example, are available as cultivars that are either rich or poor in provitamin A. Those producing and accumulating provitamin A (orange-fleshed sweet potatoes) are called biofortified, as opposed to the white-fleshed sweet potatoes, which do not accumulate provitamin A. Unfortunately, there are no natural provitamin A-containing rice cultivars. Rice plants produce ?-carotene (provitamin A) in green tissues but not in the edible part of the seed. The outer coat of the dehusked grains - the so-called aleurone layer - contains a number of valuable nutrients, e.g., vitamin B and nutritious fats, but no provitamin A. These nutrients are lost with the bran fraction in the process of milling and polishing. While it would be desirable to keep those nutrients, the fatty component is affected by oxidative processes that make the grain turn rancid. Thus, unprocessed rice - also known as brown rice - is not apt for long-term storage. Even though all required genes to produce provitamin A are present in the grain, some of them are turned off during development. In rice-based societies, the absence of ?-carotene in rice grains manifests itself in a marked incidence of blindness, disease susceptibility and premature death of small children. This paper tells the story of successful science and patent negotiations, but in 2007, so far unsuccessful placing on the market for 'Golden Rice'.