by Lena Elisabeth Faust, University of Toronto
Vitamin A deficiency is a condition primarily affecting young children and pregnant or breastfeeding mothers in South Asia and Sub-Saharan Africa, who do not have regular access to Vitamin A-rich foods.1Vitamin A deficiency is the cause of over 5.2 million cases of blindness in children around the world.2 Furthermore, this deficiency has even more severe immunological effects, which can lead to increased mortality rates among affected individuals. It is estimated that Vitamin A deficiency causes up to 2.5 million deaths per year. A promising development in the field of genetic engineering hopes to provide a sustainable solution to the problem in the form of biosynthetic, Vitamin A-rich rice, but its commercial implementation remains a challenge.
We have all heard that carrots are “good for our eyes”…but is that all there is to it?
With easy access to nutrient-rich foods, this phrase may seem like a trivial statement to those of us living in developed countries and high-income households. However, it represents a significant global health problem:; carrots, green vegetables, certain fruits, milk, eggs, and liver are all rich in Vitamin A, but these nutritious foods are unaffordable to a significant number of people, particularly in low-income countries.1 According to the World Health Organisation, Vitamin A deficiency is a moderate health concern in 49 countries and a severe health concern in 73 countries.2
Vitamin A has several important roles in the human body, one of which is the maintenance of constituents of the human eye such as the cornea and the protein rhodopsin.3 Since rhodopsin enables the absorption of light in the retina, Vitamin A deficiency (VAD) can impair vision and prevent the eyes from adapting to darkness. This condition, known as night blindness, can eventually progress to complete blindness.4
As the largest contributor to preventable child blindness in the world, VAD remains a persistent global health issue.5 Due to a lack of regular access to Vitamin A-rich foods, 5.2 million children are currently suffering from night blindness,2 with 250,000 to 500,000 new cases occurring among children each year.5 Apart from leading to impaired vision, VAD can also adversely affect the immune system. By increasing the severity of diarrheal diseases and the likelihood of contracting other diseases such as measles and malaria, VAD contributes to increase child mortality.4,6 In fact, in 50% of the aforementioned new cases of night blindness among children, the child will die less than a year after becoming blind.5 Globally, VAD is estimated to be responsible for approximately 1.3 to 2.5 million deaths every year.7
An Important Discovery: the Immunological Effects of VAD
In the early 1980s, ophthalmologist Dr. Alfred Sommer was assessing the effect of Vitamin A supplementation (VAS) on alleviating vision loss in children when he first proposed that VAD may be linked to child mortality. Despite evidence for this theory, it was not immediately accepted within the scientific community until further data was collected. To this end, Dr. Sommer conducted trials in Indonesia and Nepal with a group of 30,000 children, some of whom received VAS whilst others did not. The results were incredibly surprising – the children who did not receive VAS were 30% more likely to die than those who did.4
To explain these deaths, studies conducted since then have identified the immunological role of Vitamin A. Firstly, Vitamin A supports the function of macrophages, which are cells that destroy pathogens and activate further immune responses. Secondly, Vitamin A contributes to the production of T helper cells, which are white blood cells that take part in the adaptive immune response and increase the efficiency of processes such as the elimination of bacteria from the body. The obstruction of these processes therefore leads to increased mortality rates among Vitamin A deficient children.6
Thirdly, when mucosal barriers are damaged due to an infection, Vitamin A would normally support the innate immune system in the regeneration of these barriers. In a Vitamin A deficient child, the innate immune response is suppressed, and therefore mucosal barrier regeneration is hindered. This increases the severity of other infectious diseases and the likelihood of these diseases resulting in death.8 For example, studies in Papua New Guinea and Burkina Faso have shown that VAD increases the incidence of malaria infections by 33%.6
What is Being Done?
As a result of this discovery, VAS programs were scaled up in various affected countries. These supplementation programs usually involve the provision of Vitamin A capsules on a biannual basis to children under the age of five, who are at the highest risk of developing VAD. In many cases, the initiatives are a collaborative effort between pre-existing governmental programs, such as the National Nutrient Program in Cambodia, and international non-governmental organisations, such as Helen Keller International (HKI) and the United States Agency for International Development (USAID)9. In addition to facilitating VAS programs, the Homestead Food production Program is a HKI initiative that enables families to grow produce in their gardens and to breed fish in their local ponds as sources of Vitamin A.9
The Challenge of Complete VAS Coverage
Although the World Bank has identified VAS as one of the most cost-effective global health solutions in terms of its potential to improve a vast number of lives at a relatively low cost,10 significant barriers to eliminating the problem remain. In Cambodia, for example, it has been very difficult to monitor VAS to ensure that it reaches as many children as possible. This is due to the fact that many different international organisations are operating in various provinces across the country, leading to a lack of coordination between them. Also, the distribution of international aid in the country is unequal, and some provinces have multiple international organisations working in them whilst others remain completely without foreign aid. As the training of health workers to administer VAS is still reliant on external funding, provinces in which international organisations are not yet working often lack trained VAS personnel and consequently have lower coverage rates.10 Therefore, although the national average coverage rates for VAS have been as high as 88%, 10 some of Cambodia’s more remote provinces have coverage rates that fall far below this average.10
A Golden Alternative
Rather than international organisations looking for ways to expand their programs, the difficulty of reaching children in remote locations underlines the need to establish a more sustainable way of addressing VAD by increasing Vitamin A intake in children’s regular diets. Genetic engineering may provide a fascinating solution.
In 1992, researchers began developing “golden rice”, a genetically engineered form of the Oryza sativa species of rice, modified to contain the Vitamin A precursor beta-carotene. In 2005, an improved version was developed that contained 23 times more beta-carotene than the original,11 therefore being an excellent source of Vitamin A and a promising solution to VAD.
Who’s Going Against the Grain?
Despite its potential to ameliorate VAD, golden rice has faced criticism from organisations such as Greenpeace and the South East Asia Regional Initiatives for Community Empowerment (SEARICE). Greenpeace primarily raises the long-standing controversies associated with genetically modified foods, such as the possibility of contaminating non-modified foods through horizontal gene transfer and the claim that genetically modified foods represent a threat to human health.12 SEARICE, on the other hand, is concerned that the patent laws associated with the commercialisation of golden rice would lead to the limitation of farmer’s rights regarding the distribution, re-selling, and re-planting of seeds due to the modified seeds being considered the intellectual property of the manufacturing biotechnology company.11 Consequently, farmers would have less of a say as to what crops to plant, and would no longer be able to trade seeds with other farmers or store seeds for use in future seasons due to stricter regulation. Farmers therefore risk accumulating an excess of seeds that they cannot put to use. SEARICE thus fears that the commercialisation of the genetically engineered crop would cause a concentration of economic and legal authority among its manufacturers and threaten the livelihoods of subsistence farmers.11
Greenpeace has suggested that a sustainable and accessible source of Vitamin A could also be established through the expansion of pre-existing home gardening programs rather than turning to golden rice.12 However, factors such as space, agricultural conditions, lack of knowledge of agricultural practices pertaining to fruits and vegetables that were not previously grown, and the availability of farming tools all make such programs unrealistic on a large scale. The advantage of golden rice in this aspect is that it can draw on an agricultural system that is already in place all over South Asia and many parts of Africa. Rice farmers in these regions already possess the skills and tools to grow rice, and having a few farmers farming large fields of rice would be more efficient and cost-effective than thousands of families each attempting to keep their own small gardens.
Working With What We Have
Rice is the staple food and the predominant crop grown in many parts of South Asia, making golden rice a suitable option to target VAD in this region, which has one of the highest VAD prevalence rates worldwide1. For example, in Nepal, golden rice may be a viable alternative to conventional VAS programs such as homestead food production, due to the country’s topography being ill-suited to growing Vitamin A rich fruits and vegetables. Consequently, these foods remain largely inaccessible to low-income families, and establishing a sustainable source of Vitamin A in this way has proven difficult.4 Rice on the other hand can be grown not only in the subtropical Terai region of Nepal, but also in the Hilly Regions,13 which are home to a greater percentage of low-income families than the Terai region14 and account for 68% of the total land area.15 The implementation of golden rice agriculture would therefore be both a viable and effective initiative in terms of reaching those who need it.
Along with South Asia, children in Sub-Saharan Africa are among the most affected by VAD.1 Rice agriculture has been a concern in Africa in recent years, as the continent consumes.10 Six million tonnes of rice annually, of which 3.3 million tonnes are imported.16 While 39 African countries produce rice, 21 of these countries import between 50% and 99% of their rice in order to meet their needs.16 This means that demand far outweighs supply, leading to reliance on imports and large price increases.16
With a total of 637 million hectares of land suitable for farming, many African regions possess the resources to increase their local rice output. 16 Unfortunately, rice produces lower crop yields than other crops, such as maize, and thus an increasing amount of land is allocated to the farming of these high-yielding crops. Fortunately however, Sub-Saharan Africa consists of 24 million hectares of wetlands, which have been identified as more suitable for growing rice than other crop types.16 Cultivating golden rice in these regions would not only alleviate the burden of disease caused by VAD in Africa, but also have economic benefits by contributing to the expansion of Africa’s rice agriculture, which has gained importance in light of its growing demand.
In both Africa and South Asia, the regions most dramatically affected by VAD, golden rice may therefore serve as a viable and sustainable long-term solution to VAD by minimizing the amount of external intervention whilst establishing an accessible source of Vitamin A, even in more remote areas. It would also eliminate the need for training healthcare workers and the need to continuously monitor biannual VAS campaigns.
Prospects for Progress
The cynicism that slowed the acceptance of Dr. Sommer’s theory linking VAD to child mortality is now also an obstacle to the commercialization of golden rice, which was scheduled to begin this year11. While the rights of farmers should not be disregarded, neither should the fact that many of the poorest families living in remote areas of affected countries are still not receiving any form of VAS. We must therefore reach an acceptable compromise. For example, with the implementation of golden rice, the financial resources allocated to VAS programs could instead be used to subsidize the increased cost of genetically engineered rice to farmers, which in the long-term would be more cost-effective and conducive to eliminating VAD than continually administering VAS indefinitely.
VAD is 13th on the list of major contributors to the global burden of disease.10 Therefore, coming to an agreement is imperative for progress, and addressing VAD remains a pertinent example of how discoveries in immunology and biotechnology must be combined with an understanding of the political, social, and economic barriers to implementing solutions to current global health problems in order to effectively address them.
1. UNICEF. “Statistics by Area: Child Nutrition.” 2009. http://www.childinfo.org/vitamina.html.
2. World Health Organisation. 2009. Global Prevalence of Vitamin A Deficiency in Populations at Risk: 1995–2005. Geneva: World Health Organisation.
3. Office of Dietary Supplements. “Dietary Supplements Fact Sheet: Vitamin A.” June 5, 2013. http://ods.od.nih.gov/factsheets/VitaminA-HealthProfessional/.
4. Levine, R., and Kinder, M. 2004. Millions Saved: Proven Successes in Global Health. Washington D.C.: Center for Global Development.
5. World Health Organisation. “Vitamin A Deficiency.” September 2013. http://www.who.int/nutrition/topics/vad/en/.
6. International Regional Information Networks. “Vitamin Deficiency and Malaria.” Humanitarian News and Analysis, June 25, 2009. http://www.irinnews.org/report/85015/global-vitamin-a-deficiency-and-malaria.
7. Maziya-Dixon, B. B. 2006. Vitamin A Deficiency Is Prevalent in Children Less Than 5 Years of Age in Nigeria. The Journal of Nutrition 136 (8): 2255:2261.
8. Stephensen, C. B. 2001. Vitamin A, infection, and immune function. Annual Review of Nutrition 21: 167:192.
9. Helen Keller International. “Cambodia.” 2013. http://www.hki.org/working-worldwide/asia-pacific/cambodia/#nutrition.
10. Helen Keller International. 2007. Review of the Vitamin A Supplementation (VAS) Program for Children Aged 6-59 Months and Postpartum Women in Cambodia.
11. South East Asia Regional Initiatives for Community Empowerment. “Going Against the Golden Grain: A Primer On Golden Rice.” September 3, 2013. http://searice.org.ph/2013/09/03/going-against-the-golden-grain-a-primer-on-golden-rice-excerpts/.
12. Green Peace. “Golden Rice.” October 22, 2013. http://www.greenpeace.org/international/en/campaigns/agriculture/problem/genetic-engineering/Greenpeace-and-Golden-Rice/.
13. Smith, Georgina. “Country Profile – Nepal.” The New Agriculturist, September 2009. http://www.new-ag.info/en/country/profile.php?a=935.
14. International Fund for Agricultural Development. “Rural Poverty in Nepal”. http://www.ruralpovertyportal.org/country/home/tags/nepal
15. “Nepal”. November 22, 2013. http://www.nepalinformation.com/geography.htm.
16. Oteng, J. W., and Sant’Anna, R. 1999. Rice Production in Africa: Current Situation and Issues. International Rice Commission Newsletter V.48.