About 800 million people are currently suffering from hunger in the world, and some 2 billion suffer from some type of important nutritional deficiency. Addressing global food security becomes essential when the population is projected to increase to 9.6 billion by 2050. This will require a global food supply increase of 70 percent, as well as more nutritious foods, especially for countries with problems of nutritional deficiency.
Strategies to combat this have included international food aid programs that provide supplements through pills, or fortification of local foods in the processing phase. However, the success of these efforts has been limited, due to such factors as inconsistent external funding and limited purchasing power and access to markets and hospitals by poor populations.
Another promising strategy — one that dodges these challenges and offers long-term sustainability — has been using plant breeding programs to develop staple crops with higher nutrient levels. These biofortified crops allow people to access specific nutrients through their daily diet, such as rice in Asia, sorghum and banana in Africa, or corn in Latin America. In this way, biofortified crops are an important alternative to alleviate malnutrition in the world.
The biofortification of crops can be achieved through conventional breeding or genetic engineering. Despite its success, conventional breeding is limited to closely related (sexually compatible) plants, and therefore directly depends on the natural variation of the nutrient of interest. It also requires a lot of time to stabilize the desired trait. Although certain techniques of modern biotechnology can accelerate conventional breeding, the minimum number of generations needed for clonal propagation crops — for example, potatoes, sweet potato, banana and cassava — is estimated at seven generations. For self-fertilizing crops, such as rice, wheat and sorghum, nine generations are required, and for cross-pollinated crops, such as corn, it increases to 17 generations.
Also, breeding strategies with genetic engineering can be redirected towards the accumulation of a non-existent target nutrient in a desired tissue, such as the cereal endosperm, without compromising the micronutrient content in the milling process.
So far, much progress has been made in increasing the vitamin content in staple crops through this approach. An example is biofortification with beta-carotene, the precursor of vitamin A, which is highly important for the normal functioning of vision and the immune system. Globally, the severe deficiency of this vitamin causes 500,000 cases of irreversible blindness, millions of cases of xerophthalmia, and up to 2 million deaths per year, most of these in children under 5 years of age.
The first genetically modified (GM) crop that produced beta-carotene was rice, an important cereal that doesn’t have this nutrient in its grain. Known as “Golden Rice,” its current version was initially obtained after an insertion of a gene from a bacterium and another from maize. About 150 grams of this rice provides the recommended amount of vitamin A for a child.
This technology was developed for humanitarian purposes by a public-private consortium that released the patent for use in developing countries. It also has passed different biosafety and human consumption tests, and been approved for human consumption by the regulatory agencies of four developed countries. Unfortunately, it has not yet been authorized for cultivation in any of the countries where it is needed. This is partly due to the excessive regulation of GM crops and the strong opposition of environmental movements.
Another example is the “golden banana, developed by an Australian researcher who inserted a banana gene from Papua New Guinea, and another from bacteria, in the Cavendish banana — the most popular variety worldwide. The technology developed in Australia is transferred to a group of public researchers in Uganda, who are modifying the EAHB and Sukali Ndizi varieties, the two most consumed in Africa. Currently, both beta-carotene and iron levels continue to increase, and a human consumption test is underway in the United States. This “super banana” was named one of Time Magazine’s 25 Best Inventions of 2014, and like golden rice, the technology will be released without royalties so that it can be cultivated freely by African farmers.
Genetic engineering has also significantly increased beta-carotene in crops such as potatoes, cassava, wheat, oranges, soybean, cauliflower, melon, apples and others – all of them developed by public entities and universities.
Other important nutrients are folic acid, or folate, and iron. For the case of folate, Belgian researchers achieved an increase of 150-fold in rice. This rice could significantly reduce the risk of birth defects, such as spina bifida and other conditions of neural tube defects, caused by a deficiency of this nutrient. A Brazilian state company, EMBRAPA, also managed to increase folate 15-fold in lettuce — two leaves of that GM lettuce could provide 100 percent of the daily requirement for an adult. Additionally, EMBRAPA — in collaboration with a Mexican university —developed a GM bean with 84-fold more folic acid. In the case of iron, important increases have been achieved in rice, wheat and maize.
There are also GM crops where several nutrients have been increased, such as an African corn that was modified by researchers from a Spanish university, achieving 169 times more beta-carotene, six times more vitamin C and twice as much folate. During 2014, animal consumption tests were carried out, and in 2015 human consumption tests were being carried out as well as an experimental field trial. A second example is GM sorghum produced by the “Biofortified Sorghum Project for Africa“. This public-private partnership has managed to increase the level of beta-carotene, iron, zinc and essential amino acids, and field and greenhouse trials have already been carried out in the United States and Africa [25]. These crops have the objective of alleviating nutritional deficiency in underdeveloped countries of Africa.
Using genetic engineering to biofortify crops is not a panacea, but it does offer an important alternative. It should not be rejected as it has proven to be a useful tool to complement and/or improve conventional breeding programs.
On the other hand, the lack of regulatory frameworks for biosafety laws that allow the use of GM crops in several developing countries, or the excessive regulation in which they already have a defined framework, should be re-evaluated. Golden Rice is an example of how a technology for humanitarian purposes can be delayed for more than a decade, in part due to excessive regulation. In India alone, the cost of not commercializing Golden Rice was more than US$199 million annually and the loss of 1.4 million lives in the last decade. Let’s not increase these dismal statistics. Instead, regulators and political leaders in developing nations need to move forward in approving these nutritious and safe crops to improve health and save lives.
Recommended reviews:
De Steur H, Dieter Blancquaert, Simon Strobbe, Willy Lambert, Xavier Gellynck, Dominique Van Der Straeten. (2015). Status and market potential of transgenic biofortified crops. Nature Biotechnology. 33: 25–29
Giuliano G. (2017). Provitamin A biofortification of crop plants: a gold rush with many miners. Current Opinion in Biotechnology. 44: 169-180
Garg M, Sharma N, Sarma S, Kapoor P, Kumar A, Chunduri V, Arora P. (2018). Biofortified Crops Generated by Breeding, Agronomy, and Transgenic Approaches Are Improving Lives of Millions of People around the World. Frontiers in Nutrition. 5:12