Here are answers to common questions about Golden Rice and the Golden Rice project coordinated by IRRI.
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Golden Rice and Vitamin A deficiency
Golden Rice is a new type of rice that contains beta-carotene (provitamin A), which is converted into vitamin A as needed by the body and gives the grain its golden color. It is developed through genetic engineering and produces two new enzymes that complete the beta-carotene expression in the rice grain.
Golden Rice can be grown just like ordinary rice and varieties containing the GR2E Golden Rice trait have the same yield and agronomic performance as their conventional counterparts. The beta-carotene produced in Golden Rice grains is identical to the beta-carotene in green leafy and many types of yellow-colored vegetables and orange-colored fruit, and identical to synthetic beta-carotene found in many vitamin supplements and food ingredients.
Golden Rice is intended to complement current strategies in the fight against vitamin A deficiency (VAD) and is intended to supply up to 30–50 percent of the estimated average requirement for vitamin A for preschool age children and pregnant or lactating mothers.
Golden Rice has the potential to be a suitable complementary intervention to address vitamin A deficiency (VAD), a condition that afflicts 250 million people worldwide.
Women and children are the most vulnerable to VAD, the leading cause of childhood blindness and inability of the immune system to combat disease. The World Health Organization (WHO) reports in 2009 and 2012 indicated that 190 to 250 million preschool children worldwide are still affected by VAD. Studies have shown that vitamin A supplementation could reduce all mortality in children younger than 5 years by 24–30 percent. Vitamin A availability could prevent 1.3–2.5 million of the nearly 8 million late-infancy and preschool-age child deaths annually in developing countries with the highest risk.
Multiple approaches are needed to combat VAD, including nutrition education and consuming a diverse and nutrient rich diet; promoting breastfeeding and complementary feeding practices; vitamin A capsule supplementation; food fortification; and other public health measures aimed at the control of infectious diseases.
The existing approaches have had real successes; however, target populations are sometimes missed with these interventions, especially in remote areas. Consequently, millions are still suffering from VAD, and Golden Rice can be an additional tool in the toolbox for addressing this serious public health problem.
The US FDA letter states that the “concentration beta-carotene in GR2E rice is too low to warrant a nutrient content claim.” Does this mean that Golden Rice contains insufficient Vitamin A?
On average, Americans eat very little rice, and therefore would receive only modest amounts of beta-carotene. However, Golden Rice is intended as a complementary, food based solution for Vitamin A-deficient communities who consume rice as a staple food, eating between 200 to 300 g per day, and at these levels Golden Rice provides significant provitamin A.
To evaluate a nutrient claim, the US FDA procedure assesses whether Golden Rice can meet the requirement that “10 percent or more of the recommended daily intake (RDI) for vitamin A must be present as beta-carotene per reference amount customarily consumed” by American consumers, which the US FDA has identified as 45 g of dry rice.
In comparison, the average Filipino consumes 290g of rice every day; while in Bangladesh, average daily per capita consumption of rice is 367.19g.
Golden Rice is currently in advanced development, having achieved the target levels of beta-carotene expected to meet 30-50 percent of the estimated average requirement for vitamin A in the population sub-groups at highest risk of vitamin A deficiency (VAD), and demonstrated yield performance equivalent to conventional check varieties in multiple environments.
Product safety testing has been completed as part of the dossier submitted to regulatory agencies for assessment. Golden Rice received positive food safety evaluations from Food Standards Australia New Zealand, Health Canada, and the United States Food and Drug Administration in 2018. Golden Rice applications lodged in Bangladesh and the Philippines are still currently under review.
Additional product testing is planned, including the evaluation of consumer quality traits and human bioefficacy studies to determine the effect of Golden Rice consumption on various measures of vitamin A status. Bioefficacy testing will be conducted by an independent third-party and only once GR2E Golden Rice has received the appropriate regulatory authorization and institutional review board clearances.
The Golden Rice technology has been donated by its inventors, Professor Ingo Potrykus and Dr. Peter Beyer, for use in developing countries and in public-owned rice varieties. There are no limitations, except export sale, on the use of Golden Rice harvest, which can be locally sold, or replanted by growers. The terms of the licenses in place in the Philippines, and elsewhere, ensure that Golden Rice will cost no more than the white rice variety into which the nutritional trait has been introduced. Growers and consumers will not need to pay more for the extra nutrition.
Will Golden Rice result in changed cultivation practices that could have adverse environmental impact?
Agronomically, GR2E Golden Rice is unchanged from conventional rice. The local cultivation practices currently followed for conventional rice varieties, including the application of fertilizer, crop protection products, and labor, are directly applicable to the cultivation of those varieties containing the GR2E nutritional trait. There will be no changes in either the type of production input, or in amounts, with the cultivation of GR2E Golden Rice varieties.
No changes in farm management or cultivation practices are anticipated should GR2E Golden Rice be adopted in agriculture in the future.
Will Golden Rice require any specific deployment strategies (e.g., insect resistance management plans)?
Since GR2E Golden Rice does not possess any introduced or altered resistance to insect pests or diseases, there are no selection pressures that could drive the evolution of resistant pest populations, and no anticipated changes in current pest control practices. Thus, there would be no requirement for the adoption of insect resistance management plans or other specific deployment strategies.
Have there been any significant intended or unintended, unexpected, changes in the pest or disease susceptibility of Golden Rice?
The incidence of rice diseases (e.g., bacterial leaf blight, leaf blast, sheath rot, and sheath blight) and damage from insect pests (e.g., rice bug, yellow stem borer) were recorded for GR2E Golden Rice and unmodified control rice grown at five locations during the 2017 boro season in Bangladesh. Based on these observations, there were no indications of altered disease susceptibility of GR2E rice compared to control rice, nor were there any indications that GR2E rice was a preferred host for pest insects.
Observations on the occurrence of pest and beneficial insect species were also recorded during confined field tests of GR2E rice in the Philippines. Overall, there were no indications that GR2E rice was a preferred host for pest insects or that there were any detrimental impacts on the prevalence of beneficial species.
Based on data from the aforementioned field tests, there were no indications that the genetic modification process resulting in GR2E Golden Rice had resulted in an unintended, unexpected, change in pest or disease susceptibility.
Are there any potential adverse environmental consequences of out-crossing from Golden Rice into other rice or weedy relatives?
The introduced trait of provitamin A production in GR2E Golden Rice grains was not intended to alter a specific agronomic characteristic or to confer a fitness (selection) advantage to rice with respect to either abiotic or biotic stressors. Agronomic and phenotypic data collected from confined field tests of GR2E rice conducted at multiple locations in both Bangladesh and the Philippines have confirmed that the characteristics of rice with respect to seedling germination and vigour, plant growth and morphology, reproductive characteristics, and susceptibility to pests and diseases were not altered as an unintended, unexpected, consequence of the genetic modification process.
If the provitamin A trait is transferred by out-crossing from GR2E rice into other cultivated or weedy rice, progeny plants will not exhibit an altered selection advantage that could cause them to become more weedy or invasive in managed or unmanaged ecosystems. There are no anticipated adverse environmental consequences of introgression of the provitamin A trait from GR2E rice into other rice or sexually compatible species.
Has there been any change in pollen viability that could affect the rate of out-crossing from Golden Rice?
Rice is basically a self-pollinated crop, with limited degree of out-crossing (< 0.5 percent). The factors limiting the receptivity of rice flowers to out-crossing include a short style and stigma (1.5 to 4 mm in combined length), short anthers, limited pollen viability and brief period between opening of florets and release of pollen (between 30 seconds and 9 minutes). All wild and cultivated rice can also be wind-pollinated; however, rice pollen is short-lived with most pollen grains losing viability after approximately five minutes under typical environmental conditions.
Pollen viability is an important parameter that may affect gene flow frequencies at longer distances. As part of the characterization of GR2E Golden Rice to assess for potential unintended consequences of the genetic modification process, pollen morphology and viability were compared between GR2E and control rice. Morphologically, the appearance of pollen grains from GR2E and control rice was similar and there was no significant difference in pollen viability between samples obtained from GR2E and control rice. These data support the conclusion that pollen-mediated gene flow (out-crossing) from GR2E Golden Rice compared to conventional rice is unlikely to be changed as a result of altered pollen.
Has there been any change in the germinability of Golden Rice as a consequence of the genetic modification?
Germination and seedling growth parameters were compared between GR2E Golden Rice and control, non-transformed rice to investigate whether the genetic modification had resulted in unintended changes to the reproductive biology of rice that could affect environmental persistence or crop establishment. Germination tests conducted under two different temperature regimes did not reveal any significant differences in percent germination, total seedling length, or seedling vigour index.
The compositional evaluation of crops intentionally modified to express altered nutritional properties, such as GR2E Golden Rice, is intended to determine whether the composition differs significantly from its traditional counterpart aside from the intended change, and to assess the safety of the intended change and any unintended changes. Golden Rice is intended to produce provitamin A in the grains, unlike white rice, but otherwise its composition is intended to be equivalent to conventional rice.
The composition of key nutrients and anti-nutrients was determined in samples of GR2E rice grain (paddy), straw, and derived bran and compared to corresponding values from samples of conventional white rice. The choice of compositional parameters was based on the OECD consensus document on compositional considerations for new rice varieties, which for rice paddy included proximates, fibre, polysaccharides, fatty acids, amino acids, minerals, vitamins, and anti-nutrients. Straw and bran samples were analyzed for proximates and minerals.
The only biologically meaningful difference between GR2E Golden Rice and control rice was in levels of beta-carotene and other provitamin A carotenoids in the grain. Except for beta-carotene and related carotenoids, the compositional parameters measured in GR2E rice were within or similar to the range of natural variability of those components in conventional rice varieties with a history of safe consumption.
Other than the intended production of provitamin A in the grains, GR2E Golden Rice was found to be compositionally equivalent to conventional rice and there were no observed unintended, unexpected, changes in nutrient composition as a result of the genetic modification process.
As a macronutrient, protein is an essential component of the human diet and consumption of proteins as a class of dietary substances is not inherently associated with adverse effects. Of the thousands of proteins that may be ingested daily, only a very small number have the potential to exert anti-nutritional or toxic effects, or elicit allergic reaction in previously sensitized individuals.
Assessing the safety of newly-expressed proteins produced in the edible portions of a genetically engineered food crop is an integral component of the overall safety assessment. As there is currently no single criterion that is sufficiently predictive of potential toxicity or allergenicity, a “weight-of-evidence” approach is recommended for hazard identification that considers the history of use, amino acid sequence similarity to known toxins or allergens, function or mode of action, digestibility under standardized in vitro conditions, stability to heat or processing, and expression levels and potential dietary exposure.
GR2E Golden Rice contains three newly expressed proteins:
- ZmPSY1 – phytoene synthase from another food crop, maize, which catalyzes the condensations of two molecules of geranylgeranyl diphosphate to form 11-cis-phytoene, the first committed step in the carotenoid biosynthetic pathway;
- CRTI – phytoene desaturase from a common bacterial species (Pantoea ananatis), which catalyzes the conversion of 11-cis-phytoene to all-trans-lycopene, an immediate precursor of beta-carotene; and
- PMI – phosphomannose isomerase from the bacterium Escherichia coli, a normal inhabitant of the intestinal flora of humans and animals, which allows for positive selection of transformed plants on media containing mannose as the sole carbon source.
Each of the newly expressed proteins in GR2E rice was evaluated using the “weight-of-evidence” approach, and for each protein:
- bioinformatics studies confirmed the lack of any significant amino acid sequence similarity to proteins known to be toxic via oral exposure or to allergens;
- digestibility studies confirmed rapid degradation in the presence of simulated gastric fluid containing pepsin; and
- heat stability studies demonstrated rapid inactivation at temperatures below those used for cooking or processing.
In addition, mouse acute oral toxicity testing of the CRTI and PMI proteins showed a lack of toxic effects at dosages thousands of times more than any realistically conceivable dietary exposure from consuming GR2E rice. Taken together, the evidence indicates that neither ZmPSY1, CRTI, or PMI are likely to be toxic or result in allergic reactions in humans or animals. Conventional white rice is not considered a source of toxins or a significant source of anti-nutritional factors, nor is it considered by allergists to be a common allergenic food, and the genetic modification resulting in GR2E Golden Rice has not altered this safety profile.
The safety assessment of all foods derived from genetically engineered plants is based on the evaluation of these foods relative to their conventional counterparts that have a history of safe use. This concept has been described in international consensus documents, such as the Principles for the Risk Analysis of Foods Derived from Modern Biotechnology and the Guideline for the Conduct of Food Safety Assessment of Foods Derived from Recombinant-DNA Plants published by the Codex Alimentarius Commission.
In conducting the safety assessment of food/feed derived from GR2E Golden Rice, a number of criteria have been addressed including:
- characterisation of the transferred genes and their origin, function, and stability in the rice genome;
- characterization and concentrations of newly expressed proteins in the whole food;
- comprehensive nutrient compositional analyses of grain, straw, and derived bran;
- evaluation of intended and unintended changes; and
- the potential for any newly expressed proteins to be either allergic or toxic in humans or animals.
The purpose of these evaluations was to determine whether the use of GR2E Golden Rice in food, feed, or for processing, would raise any new safety concerns relative to conventional rice. The studies were not intended to address questions related to the efficacy of GR2E Golden Rice in helping to address vitamin A deficiency in affected population sub-groups, which can only be adequately addressed following regulatory authorization.
No potential public health and safety concerns were identified in the assessment of GR2E Golden Rice. Collectively, the data support the conclusion that food and/or livestock animal feed derived from provitamin A biofortified GR2E rice is as safe as food or feed derived from conventional rice varieties.
Golden Rice Status and Updates
Have regulators assessed the risks concerning the application for the proposed Golden Rice field trials in the Philippines?
The Department of Agriculture-Bureau of Plant Industry (DA-BPI) in the Philippines released a consolidated risk assessment report on the application submitted by PhilRice for the proposed field trials of Golden Rice. The report indicates positive assessments from the DA-BPI Scientific and Technical Review panel,biosafety committees of the Department of Environment and Natural Resources and Department of Health, and a socio-economic ethical and cultural expert, which resulted in a recommendation to grant a biosafety permit for the field trial.
Transparency and public participation are key components of biosafety regulatory approval under the Joint Department Circular No. 1 series of 2016. In addition to the consolidated risk assessment report, local government resolutions that emanate from the public consultations and a report summarizing feedback gathered during the public comment period will be assessed as part of the decision-making process.
There have been reports that Golden Rice field trials resulted in stunted plants and reduced grain yield. Is this true?
In 2014, we shared an update on the results of the multilocation trials (MLTs) conducted in 2012-2013 that used the most advanced event of Golden Rice at that time, GR2R. Results from these MLTs showed that while the target level of beta-carotene in the grain was attained, average yield was lower than that of comparable local varieties preferred by farmers. Hence, a decision has been reached to use more promising events such as GR2E to advance the development of Golden Rice.
Research and development of Golden Rice using GR2E are ongoing and moving toward deployment. From October 2014 to July 2017, a series of confined field tests (CFTs) were successfully conducted at IRRI and PhilRice in the Philippines and at five different locations within Bangladesh to assess the agronomic performance of GR2E introgression lines in comparison with their respective recipient parents. The results from the CFTs were also helpful in selecting a subset of lines with suitable agronomic and product performance for advancement.
The results from the CFTs confirmed there are no unintended effects of the GR2E event on agronomic performance, yield, and grain quality. Moreover, there were no observed differences for their pest and disease reactions. Except for the intended production of beta-carotene, all other nutritional components of the rice have been maintained.
A number of GR2E introgression lines with acceptable agronomic, yield and grain quality traits, and having a significant concentration of carotenoids in the milled rice as measured two months post-harvest, were selected for further evaluation in MLTs in 2017.
Regulatory updates in Bangladesh
In Bangladesh, the application for environmental and food safety assessment of GR2E BRRI dhan29 Golden Rice was lodged with the Ministry of Agriculture on 26 November 2017 and the Ministry of Environment and Forest on 04 December 2017. This application is a necessary step for inclusion in the National Seed Board rice variety listing.
Regulatory updates in the Philippines
Application for the conduct of field trials
In accordance with the Joint Department Circular No. 1 series of 2016, the Department of Agriculture-Bureau of Plant Industry (DA-BPI) has instructed PhilRice to proceed with the public consultation process in the localities identified in its application, dated 28 February 2017, for a biosafety permit for the conduct of GR2E Golden Rice field trials submitted by PhilRice.
The consultation process is comprised of Public Information Sheet postings in accessible community locations, a 30-day public comment period, and the public hearing, which took place on 18 July 2018 in Science City of Munoz, Nueva Ecija, and on 19 July 2018 in San Mateo, Isabela. The Sangguniang Panlungsod of the Science City of Muñoz and Sangguniang Bayan of San Mateo each passed resolutions supporting the conduct of Golden Rice field trials in their respective communities. PhilRice received copies of these local endorsements, which have been submitted to DA-BPI, along with a summary report. On May 20, 2019, DA-BPI Director George Y. Culaste issued the BPI Biosafety Permit for Field Trial Number 10-001.
Application for direct use
PhilRice, in coordination with IRRI, led a series of briefings from July to 2017 in Quezon City, Nueva Ecija, Isabela, Ilocos Norte, Agusan del Norte, Albay, Camarines Sur, and Tagaytay City. Different stakeholders, such as farmers, policy makers, students and teachers, research and development professionals, medical and health practitioners, and media and public information officers, including those from women’s groups and the religious sectors attended these briefings, which were held during the 60-day public comment period for the joint PhilRice-IRRI application for a biosafety permit for the direct use in food, feed, or for processing, of GR2E Golden Rice. The application was submitted in March 2017 and the PIS was published on 26 July 2017.
DA-BPI has published the Consolidated Assessment Report for the FFP application on its website. They noted that “After reviewing the accomplished biosafety forms and socio-economic, ethical and cultural questionnaire, and supporting documents submitted by the applicant, the assessors, namely: the Scientific and Technical Review Panel (STRP), the BPI- Plant Products Safety Services Division (BPI-PPSSD), the Bureau of Animal Industry (BAI), Department of Environment and Natural Resources – Biosafety Committee (DENR-BC), Department of Health – BC (DOH-BC), and Socio-economic, Ethical and Cultural (SEC) concurred that GR2E Rice is as safe for human food and animal feed as its conventional counterpart.
Global Regulatory updates
Outside of the Philippines and Bangladesh, applications for food or food and feed safety review of GR2E Golden Rice have been submitted to the US Food and Drug Administration, Food Standards Australia New Zealand, and to Health Canada. Collectively, the data presented in these application submissions have not identified potential health and safety concerns, and support the conclusion that food and/or livestock animal feed derived from provitamin A biofortified GR2E rice is as safe and nutritious as food or feed derived from conventional rice varieties. Detailed information on the product safety studies can be found here.
On 7 August 2017, FSANZ published a call for submission of comments on the Golden Rice application and noted that “FSANZ has conducted a thorough safety assessment, including a dietary intake assessment (DIA), and has determined there are no public health or safety concerns.” The regulatory process under FSANZ was completed on 22 February 2018 with the publication of the Food Standards variance in the Commonwealth of Australia Gazette.
In its notice of decision dated 16 March 2018, Health Canada declared that “changes made in this rice variety did not pose a greater risk to human health than rice varieties currently available on the Canadian market”, further noting that “GR2E would have no impact on allergies”, and that there were no differences in the nutritional value of GR2E compared to other traditional rice varieties available for consumption except for increased levels of provitamin A.
Golden Rice completed a third positive food safety evaluation on 24 May 2018, this time from the United States Food and Drug Administration (US FDA). In an official letter, the US FDA concurred with IRRI’s assessment regarding the safety and nutrition of Golden Rice.