Biofortified rice as a contribution to the alleviation of life-threatening micronutrient deficiencies in developing countries

A good start is a food start!

Dietary micronutrient deficiencies, such as the lack of vitamin A, iodine, iron or zinc, are a major source of morbidity (increased susceptibility to disease) and mortality worldwide. These deficiencies affect particularly children, impairing their immune system 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 balanced diet, is by way of nutrient-dense staple crops. Sweet potatoes, for example, are available as varieties that are either rich or poor in provitamin A. Those producing and accumulating provitamin A (orange-fleshed sweetpotatoes) are called biofortified,* as opposed to the white-fleshed sweet potatoes, which do not accumulate provitamin A. In this case, what needs to be done is to introduce the biofortified varieties to people used to the white-fleshed varieties, as is happening at present in southern Africa by introducing South American varieties of orange-fleshed sweetpotatoes.

Unfortunately, there are no natural provitamin A-containing rice varieties. In rice-based societies, the absence of β-carotene in rice grains manifests itself in a marked incidence of blindness and susceptibility to disease, leading to an increased incidence of premature death of small children, the weakest link in the chain.

Rice plants produce β-carotene (provitamin A) in green tissues but not in the endosperm (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 with the grain, the fatty components are affected by oxidative processes that make the grain turn rancid when exposed to air. 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. This is where the ingenuity of the Golden Rice inventors, Profs Ingo Potrykus (formerly ETH Zurich) and Peter Beyer (University of Freiburg) comes into play. They figured out how to turn on this complex pathway again with a minor intervention.

The shocking fact is that, far from reaching the envisaged Millenium Development Goals, more than 10 million children under the age of five are still dying every year. A high proportion of those children die victims of common diseases that could be prevented through a better nutrition. This number has been equated with a ‘Nutritional Holocaust’ . It is unfortunate that the world is not embracing more readily a number of approaches wih the potential to substantially reduce the number of deaths. It has been calculated that the life of 25 percent of those children could be spared by providing them with diets that included crops biofortified with provitamin A (beta-carotene) and zinc. Golden Rice is such a biofortified crop. Those involved in the project are hopeful that in a near future Golden Rice will be growing in farmers' fields and helping to improve the diets of millions of people.

Golden Rice grains are easily recognisable by their yellow to orange colour. The stronger the colour the more β-carotene. While a yellow rice is still unfamiliar to most of us, it is hoped that the pleasant colour will help promote its adoption. Would you believe that once upon a time carrots were white or purple? Orange-coloured carrots are the product of a mutation selected by a Dutch horticulturist a few hundred years ago, because it was the colour of the Dutch Royal House of Orange-Nassau!

*Welch RM and Graham RD (2004) Breeding for micronutrients in staple food crops from a human nutrition perspective. J Exp Bot 55:353-364.

Quantum leap:

Golden Rice accumulates provitamin A (β-carotene) in the grain

Rice produces β-carotene in the leaves but not in the grain, where the biosynthetic pathway is turned off during plant development. In Golden Rice two genes have been inserted into the rice genome by genetic engineering, to restart the carotenoid biosynthetic pathway leading to the production and accumulation of β-carotene in the grains. Both genes are naturally involved in carotene biosynthesis. The difference here is that the reconstructed pathway is not subject to downregulation, as usually happens in the grain.

Since a prototype of Golden Rice was developed in the year 2000, new lines with higher β-carotene content have been generated. The intensity of the golden colour is a visual indicator of the concentration of β-carotene in the endosperm.Our goal is to make sure that people living in rice-based societies get a full complement of provitamin A from their traditional diets. This would apply to countries such as India, Vietnam, Bangladesh. the Philippines, and Indonesia. Golden Rice could still be a valuable complement to children's diets in many countries by contributing to the reduction of clinical and sub-clinical vitamin A deficiency-related diseases.

Many people are aware that vitamin A has something to do with vision, especially at night. But many are not aware of the central role it plays in maintaining the integrity of the immune system. According to the World Health Organization, dietary vitamin A deficiency (VAD) compromises the immune systems of approximately 40 percent of children under the age of five in the developing world, greatly increasing the risk of severe illnesses from common childhood infections, thus causing hundreds of thousands of unnecessary deaths among them.

In remote rural areas Golden Rice could constitute a major contribution towards sustainable vitamin A delivery. To achieve this goal a strong, concerted, and interdisciplinary effort is needed. This effort must include scientists, breeders, farmers, regulators, policy-makers, and extensionists. The latter will play a central role in educating farmers and consumers as to their available options. While the most desirable option woud be a varied and adequate diet, this goal is not always achievable, at least not in the short term. The reasons are manifold, ranging from tradition to geographical and economical limitations. Golden Rice is a step in the right direction in that it does not create new dependencies or displace traditional foodstuff.

Golden Rice will reach those who need it at no additional cost

Growers will be able to reuse their seed as they please

Those most in need of this new seed-based technology are those who can least afford buying an adequate diet, rich in essential nutrients. This has been taken into consideration by the creators of Golden Rice, Profs Peter Beyer and Ingo Portrykus, and the crop protection company Syngenta, who have worked together to make the latest, improved version of Golden Rice available for humanitarian use in developing countries, free of charge.

The Golden Rice Humanitarian Board encourages further research to determine how the technology may play a part in the ongoing global effort to fight Vitamin A Deficiency in poor countries. While Golden Rice is an exciting development, it is important to keep in mind that malnutrition is to a great extent rooted in political, economic and cultural issues that will not be solved by a technical fix. Yet Golden Rice offers people in developing countries a valuable and affordable choice in the fight against the scourge of malnutrition.

This site is maintained by the Golden Rice Humanitarian Board for the purpose of providing information on the background and progress of the Golden Rice Humanitarian Project.

Eat orange! We really mean it!