UPDATE: This is part of a series on GMOs. Links for all of the posts for this series are indexed on my highlights page. Check out all of them.
Today I’d like to highlight one genetic engineering project centered on good intentions rather than a corporate bottom line. It is the story of Golden Rice, a variety engineered to be fortified with Vitamin A in an attempt to alleviate the problems of Vitamin A deficiency in the developing world.
Vitamin A is an essential nutrient important for healthy vision, proper growth and development and a robust immune system. It can be acquired through a diet that is rich in plant pigments called carotenoids from foods like carrots, tomatoes, dark green leafy vegetables, pumpkins and other squash etc. Vitamin A deficiency is a world health problem in developing nations where millions of young children and pregnant mothers do not have adequate Vitamin A intake. Because of its key role in growth, development and a healthy immune system, lack of this nutrient has profound consequences on child mortality.
Vitamin A deficiency represents a case where the conditions and consequences are well understood. Multiple strategies are being used to combat this problem on a global scale including administering Vitamin A supplements, facilitating dietary diversity to include cultivation of Vitamin A-rich crops, and biofortification of crops to have enhanced Vitamin A content. In Africa, the strategy was to introduce orange-fleshed sweet potatoes to replace the traditionally grown white-fleshed variety. Another strategy is to engineer Vitamin A production into a staple crop suitable for the Asian continent. This is where Golden rice comes in.
Golden rice has been engineered to produce beta carotene, a source of Vitamin A in its seeds. This was accomplished by adding two genes in the carotenoid biosynthetic pathway (one from another plant and another from a bacterium) to ensure accumulation of beta carotene in the grain. This work has been carried out by scientists working in academia and non-profit organizations like IRRI, the International Rice Research Institute. Golden Rice is intended to be freely/cheaply distributed to farmers in developing countries struggling with Vitamin A deficiency. For the latest Golden Rice variety, about one cup of uncooked rice will supply ~50% of the recommended daily allowance of Vitamin A for an adult.
Manipulating dietary staples is not without controversy, nevermind good intentions. Opponents think that other methods (like dietary diversification) are more effective at combatting Vitamin A deficiency. Others view this example of genetic engineering as overkill for the problem and suspect that Golden Rice is merely a propaganda tool to gain wider acceptance of GMOs. Still others are just suspicious of anyone suggesting changes to traditional foods.*
Nevertheless, one cannot argue that the technique of genetic engineering in and of itself is inherently evil given the premise of the Golden Rice project. In the case of Vitamin A deficiency, there will be no one solution. Sure, Golden Rice has the potential to curb Vitamin A deficiency, but it was never intended as a singular solution to the exclusion of all others. Golden Rice was developed because the tools were available and it could be done. Why not use all available tools in the toolbox?
This is where we come to the more difficult aspects of genetic modification of food plants. Genetic engineering offers a powerful new tool, so let’s decide how it will be implemented. There are many aspects regarding regulation, safety, environmental impact, consumer information and the business models for modern agriculture that must be addressed. Contrary to the way the GMO argument is usually framed, these issues can all be disentangled from the science of genetic engineering. Those topics will be featured in the next posts in this series.
* I wonder if it’s the fact that the quick timescale of changes to food using genetic engineering makes it seem so scary. Where do we draw the line on what is natural? Agriculturally important plants and animals have been subject to genetic modification for millennia through selective breeding, taking advantage of natural variations and induced mutations to yield new varieties better suited for human needs. They bear little resemblance to anything available in the wild. Consider that even the carrot was not always orange. http://www.carrotmuseum.co.uk/history.html Yet, today no one seems to have a problem with consuming modern carrots that are full of beta carotene.
For more information on Golden Rice: