How does Golden Rice work
From prototype to product
The major micronutrient deficiencies concern iron, zinc, and vitamin A. Vitamin A deficiency is widespread among
rice-depending poor because rice grains do not contain provitamin A (plants produce a precursor of vitamin A; hence
called provitamin A, and other, related compounds, called carotenoids). Dependence on rice as the predominant food
source, therefore, necessarily leads to vitamin A deficiency, most severely affecting children and pregnant women.
A major goal of the Golden Rice Project is to be capable of supplying the recommended daily intake of vitamin A to
people living in rice-based societies. The tools necessary to achieve this goal have been recently improved with the development of a
new version of Golden Rice (GR2).The picture above shows the pleasant orange, translucent colour of GR2, which stems
from an increased accumulation of beta-carotene in the grain as compared to the earlier GR1.
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Our partial solution to a world-wide problem is based on genetic engineering. The approach is based on the use of precursor molecules present in the rice grain and the filling in of a gap in the pathway to beta-carotene production, a pathway that is usually active in rice leaves but not in the grain. In the quest for more nutritional crops, wo/man has over the last ten-thousand years or so selected characteristics that are not always of benefit to the plant but to humans. This is another case in point, where we redirect a plant to produce a component normally involved in photosynthesis in a photosynthetically inactive tissue, for our sake.
We endeavour to offer a useful tool to ongoing health programmes by increasing the coverage of vitamin supply, especially to remote rural areas. Our hopes are rooted on the fact that seed represent a sustainable approach to fortification. Once farmers start growing Golden Rice, funds used for some of those supplementation programmes (in the form of pills and capsules) could be freed and redirected to other much needed programmes. Experience over time has demonstrated that rice will stay a main caloric intake source for many people, because it is easy to grow, well adapted for long term storage, and cheap to obtain. Good beta-carotene sources do not grow everywhere where vitamin deficiency is a problem. Moreover, it has been recently shown that bioavailability of beta-carotene from vegetables—to everybody's dismay—is more inefficient than previously thought, and thus the required increase in daily vegetable intake would be economically unattainable for many poor people.