Evaluating iron and zinc bioavailability from biofortified potatoes to reduce malnutrition in the Andean highlands.
Lead Research Organisation:
Quadram Institute
Department Name: Food Innovation and Health
Abstract
Iron and zinc deficiency are global problems, with high prevalence in Asia, Sub-Saharan Africa and South America. While iron and zinc supplementation and food fortification programmes have been shown to be efficacious in certain situations, their implementation requires good infrastructure, significant investment and safe delivery systems. The development of crops with enhanced levels of bioavailable iron and zinc - so called biofortification - is a sustainable and cost-effective complementary strategy that has the potential to provide sufficient iron and zinc for resource poor rural and urban communities, such as those in the Andean highlands. There has been significant effort within the international community to breed new varieties of staple crops that have enhanced levels of iron and/or zinc. It is however difficult to predict whether the additional iron and zinc in biofortified crops would be bioavailable - that is effectively absorbed from the diet into the body to improve iron and zinc status. The risk in breeding these biofortified crops is that the investment in crop development will have limited impact if the iron and zinc is not bioavailable.
Iron and zinc biofortified potato are an ideal crop to contribute to a reduction in iron and zinc deficiencies in the Andean highlands for two major reasons. Firstly, unlike cereals and legumes, potatoes have very low levels of phytates which inhibit iron bioavailability, and this is combined with a relatively high concentration of vitamin C which promotes iron absorption - an ideal combination to maximize bioavailability. Secondly, potatoes are the major staple in the diet amongst the iron and zinc-deficient Andean population, and are largely consumed without other foods. Thus, while various strategies including agricultural diversification have potential to alleviate micronutrient deficiencies and should be considered in an integrated approach, biological, cultural and economic factors suggest that the introduction of iron and zinc biofortified potatoes may be an effective approach to have a significant contribution to reducing iron and zinc deficiencies. Quantifying the bioavailability of iron and zinc at this time is critical.
The bioavailability of iron and zinc from biofortified crops can only be meaningfully quantified through human dietary intervention studies in which foods made from the biofortified crops are labelled with stable isotopes of iron or zinc, which are subsequently quantified human tissues to provide a measure of bioavailability. These studies are technically challenging, but of the utmost importance for the success of biofortification strategies.
To quantify the potential impact of the introduction of biofortified potatoes, data from the human studies will be used within a Disability Adjusted Life Year (DALY) modelling approach. This method has been successfully applied to assess the potential impact of other biofortified crops to alleviate micronutrients deficiencies. Furthermore, we will use data from the proposed research along with that from other studies to develop iron dietary intake guidelines for low and middle-income countries.
If we find compelling evidence through the human intervention studies and the subsequent DALY modeling that iron and zinc biofortified potatoes can contribute to alleviation of iron and zinc deficiencies in low and middle income countries, it will provide the justification for investment from the international donor community and national research programmes for further development and selection of clones of diploid and tetraploid potatoes that have enhanced iron and zinc content, and their transfer to national agricultural research programmes in south America, Asia and Africa. Subsequently, these programmes and their associated extension programmes and NGOs will ensure the introduction of biofortified potatoes to small scale farmers in regions of high iron and zinc deficiencies.
Iron and zinc biofortified potato are an ideal crop to contribute to a reduction in iron and zinc deficiencies in the Andean highlands for two major reasons. Firstly, unlike cereals and legumes, potatoes have very low levels of phytates which inhibit iron bioavailability, and this is combined with a relatively high concentration of vitamin C which promotes iron absorption - an ideal combination to maximize bioavailability. Secondly, potatoes are the major staple in the diet amongst the iron and zinc-deficient Andean population, and are largely consumed without other foods. Thus, while various strategies including agricultural diversification have potential to alleviate micronutrient deficiencies and should be considered in an integrated approach, biological, cultural and economic factors suggest that the introduction of iron and zinc biofortified potatoes may be an effective approach to have a significant contribution to reducing iron and zinc deficiencies. Quantifying the bioavailability of iron and zinc at this time is critical.
The bioavailability of iron and zinc from biofortified crops can only be meaningfully quantified through human dietary intervention studies in which foods made from the biofortified crops are labelled with stable isotopes of iron or zinc, which are subsequently quantified human tissues to provide a measure of bioavailability. These studies are technically challenging, but of the utmost importance for the success of biofortification strategies.
To quantify the potential impact of the introduction of biofortified potatoes, data from the human studies will be used within a Disability Adjusted Life Year (DALY) modelling approach. This method has been successfully applied to assess the potential impact of other biofortified crops to alleviate micronutrients deficiencies. Furthermore, we will use data from the proposed research along with that from other studies to develop iron dietary intake guidelines for low and middle-income countries.
If we find compelling evidence through the human intervention studies and the subsequent DALY modeling that iron and zinc biofortified potatoes can contribute to alleviation of iron and zinc deficiencies in low and middle income countries, it will provide the justification for investment from the international donor community and national research programmes for further development and selection of clones of diploid and tetraploid potatoes that have enhanced iron and zinc content, and their transfer to national agricultural research programmes in south America, Asia and Africa. Subsequently, these programmes and their associated extension programmes and NGOs will ensure the introduction of biofortified potatoes to small scale farmers in regions of high iron and zinc deficiencies.
Technical Summary
Iron bioavailability studies: We will compare bioavailability of iron from a non-fortified potato variety with a biofortified potato that has significantly higher iron content (p<0.001) though the use of a randomized cross-over intervention study. Female volunteers will consume both biofortified potato extrinsically labelled with 58FeSO4 and a nonfortified potato labelled with 57FeSO4. Forty women with marginal iron status (plasma ferritin < 25 ng/ml) will be selected from an initial screening of 180 women. Every woman will receive 2 different types of test meals in a series of 20 servings for 10 d each. Blood samples will be collected during screening and on days 1, 15, 26 and 40 and the amount of 58Fe and 57Fe incorporated into haemoglobin and serum ferritin quantified.
Zinc bioavailability study: We will compare bioavailability of zinc from a non-fortified potato variety with that of a biofortified potato that has significantly higher zinc content (p<0.001) with a crossover study. Volunteers will be randomly assigned to receive first either the biofortified or the nonfortified potato, and receive the second meal 30 days later. Zinc absorption from two meals will be measured using the double stable isotope technique. Every volunteer will be given an i.v. infusion of 70zinc and two test meals of 300 g cooked potato labelled extrinsically with 67zinc separated by 3-4 hr. A spot urine sample will be collected 96 hours after each set of test meal and the ratio of the two isotopes measured in order to calculate absorption of zinc from the test meal.
Modelling and Impact assessment: Data on bioavailability will be used in a Disability Adjusted Life Year model to assess the potential impact of biofortified potatoes to alleviate iron and zinc deficiencies in the Andean Highlands and low and middle-income countries elsewhere. Additional modelling will be undertaken to derive recommendations for dietary iron and zinc intake for low and middle-income countries
Zinc bioavailability study: We will compare bioavailability of zinc from a non-fortified potato variety with that of a biofortified potato that has significantly higher zinc content (p<0.001) with a crossover study. Volunteers will be randomly assigned to receive first either the biofortified or the nonfortified potato, and receive the second meal 30 days later. Zinc absorption from two meals will be measured using the double stable isotope technique. Every volunteer will be given an i.v. infusion of 70zinc and two test meals of 300 g cooked potato labelled extrinsically with 67zinc separated by 3-4 hr. A spot urine sample will be collected 96 hours after each set of test meal and the ratio of the two isotopes measured in order to calculate absorption of zinc from the test meal.
Modelling and Impact assessment: Data on bioavailability will be used in a Disability Adjusted Life Year model to assess the potential impact of biofortified potatoes to alleviate iron and zinc deficiencies in the Andean Highlands and low and middle-income countries elsewhere. Additional modelling will be undertaken to derive recommendations for dietary iron and zinc intake for low and middle-income countries
Planned Impact
The ultimate target beneficiaries of the proposed research are resource-poor people in low and middle-income countries who lives are blighted through iron and zinc deficiencies. Iron deficiency is widely considered to be the largest nutritional deficiency worldwide and the major cause of anaemia. Iron deficiency anaemia (IDA) is estimated to affect 1.24 billion people, the majority of whom are children and women from resource-poor countries [1]. Deficiency due to dietary iron intake is frequently exacerbated by concomitant parasitic and bacterial infections and contributes to over 120 000 maternal deaths a year. IDA irreparably limits the cognitive development of children and leads to poor outcomes in pregnancy [1]. Zinc has a role in over 300 enzymes in the majority of metabolic pathways in humans. Zinc deficiency leads to multiple and complex physiological disorders and impairment of growth and cognitive development of children. Extent of deficiency has been estimated to be up to 30% of the population of low and middle-income countries [2]. Despite considerable investment in the past 25 years in nutrition interventions with iron and zinc supplementation and food fortification, it has been challenging to significantly decrease the burden of these micronutrient deficiencies in resource-poor countries. A strategy of biofortification in which sufficient micronutrients are delivered as part of the diet has been widely advocated, and there is evidence that this approach can be sustainable and effective. Iron and zinc biofortified potatoes may have an important role to play in communities in which potatoes are the major component of the diet, exemplified by those in the Andean Highlands, but may also contribute to alleviating deficiencies in other communities in which potatoes are an important component of a more diverse diet.
The successful introduction of biofortified potatoes into these communities will take several years. The proposed research will have more immediate impact on several groups of other intermediate beneficiaries:
Donor agencies: The results of the proposed study are critical to justify further investment in potato biofortification by donor agencies, including Bill and Melinda Gates Foundation, The World Bank, bilateral aid agencies and the European Union. CIP in collaboration with national research programmes, NGOs and farmers have spent more than fifteen years selecting iron and zinc biofortified diploid potatoes. Further significant investment is required to develop elite biofortified potatoes for introduction into Africa and Asia. However, the proposed bioavailability studies and subsequent impact assessment are required to justify investment.
Public health workers and nutrition scientists: The results of the proposed research will inform nutrition scientists and public health workers whether biofortified potatoes have the potential to contribute to the alleviation of iron and zinc deficiencies, and specifically how much potatoes need to be consumed in a single meal and how frequently to make a significant difference to iron and zinc status.
Plant breeders and crop scientists: The results of the proposed research will provide specific target for iron and zinc content for breeders, enabling effective decisions about how much additional effort is required to produce breeding line with marginal increases in iron and zinc.
Research scientists and nutritionists: The programme will provide training in undertaking human intervention studies and iron and zinc stable isotope studies for scientists in Peru. This will include protocol design, obtaining ethics and the specific aspects of working with stable isotopes, and diet intake assessment.
[1] Stellae at al (2018) Proceedings of Nutrition Society, 10th July https://doi.org/10.1017/S0029665118000460. [2] Wessells and Brown (201) Plos One doi.org/10.1371/journal.pone.0050568
The successful introduction of biofortified potatoes into these communities will take several years. The proposed research will have more immediate impact on several groups of other intermediate beneficiaries:
Donor agencies: The results of the proposed study are critical to justify further investment in potato biofortification by donor agencies, including Bill and Melinda Gates Foundation, The World Bank, bilateral aid agencies and the European Union. CIP in collaboration with national research programmes, NGOs and farmers have spent more than fifteen years selecting iron and zinc biofortified diploid potatoes. Further significant investment is required to develop elite biofortified potatoes for introduction into Africa and Asia. However, the proposed bioavailability studies and subsequent impact assessment are required to justify investment.
Public health workers and nutrition scientists: The results of the proposed research will inform nutrition scientists and public health workers whether biofortified potatoes have the potential to contribute to the alleviation of iron and zinc deficiencies, and specifically how much potatoes need to be consumed in a single meal and how frequently to make a significant difference to iron and zinc status.
Plant breeders and crop scientists: The results of the proposed research will provide specific target for iron and zinc content for breeders, enabling effective decisions about how much additional effort is required to produce breeding line with marginal increases in iron and zinc.
Research scientists and nutritionists: The programme will provide training in undertaking human intervention studies and iron and zinc stable isotope studies for scientists in Peru. This will include protocol design, obtaining ethics and the specific aspects of working with stable isotopes, and diet intake assessment.
[1] Stellae at al (2018) Proceedings of Nutrition Society, 10th July https://doi.org/10.1017/S0029665118000460. [2] Wessells and Brown (201) Plos One doi.org/10.1371/journal.pone.0050568
Publications
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Liria-Domínguez R
(2023)
Biofortified Yellow-Fleshed Potatoes Provide More Absorbable Zinc than a Commonly Consumed Variety: A Randomized Trial Using Stable Isotopes in Women in the Peruvian Highlands.
in The Journal of nutrition
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Fairweather-Tait S
(2020)
Dietary Iron Bioavailability: A Simple Model That Can Be Used to Derive Country-Specific Values for Adult Men and Women.
in Food and nutrition bulletin
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Description | By screening hundreds of different potato varieties, varieties have been identified that have significantly higher levels of iron and other varieties with significantly higher levels of zinc. These varieties contain 60-100% more of these essential minerals than the typically consumed potato variety in Peru. Potatoes are consumed in very large quantities in several regions of Peru where they are the staple food. These regions often also have high rates of nutrient deficiencies, including iron and deficiency, and therefore these potatoes represent an excellent food to biofortify with iron and zinc. The potatoes have been grown in large numbers to provide the potatoes for a dietary intervention that will assess the bioavailability (fractional absorption) of iron and of zinc. The dietary intervention studies have been completed and the analyses of tissue samples are being completed. The project was delayed by the COVID restrictions which resulted in the loss of the full harvest in 2020 which had to be repeated then in 2021. |
Exploitation Route | Potato varieties that contain higher levels of iron and of zinc can be grown more widely and could replace the existing commercial varieties, and in this way increase the intakes of iron and zinc in Peru (and eventually elsewhere). It is anticipated that the fractional absorption of iron and zinc will be relatively high in these potatoes because they contain relatively low levels of antinutrients such as phytate and polyphenols. |
Sectors | Agriculture, Food and Drink,Education |
Description | The ODA funded research resulted in the selection of iron-rich and zinc-rich potato clones that were shown to perform well in field trials and which delivered significantly more bioavailable iron/zinc than the current potato varieties that are consumed in Peru. These clones are being grown up by CIP farmers and made available to potato farmers in Peru, and their wider use is expected to improve the status of consumers with regards their iron and zinc status. This is important in Peru, especially in the highland communities, because there is a high rate of iron andn zinc deficiency.insufficiency, and potatoes are the staple food source, so access to biofortified potatoes is expected to have a significant impact on the nutritional status and health of these communities. A daily adjusted life years (DALYs) analysis has demonstrated the potential impact of replacing existing cultivars with the biofortified clones on iron and zind deficiency/insufficiency both in regions and across Peru, but also in other regions where potatoes are the staple source of starch, for example certain counries in Africa. CIP is working with HarvestPlus to explore routes to effect the widespread use of the micronutrient rich varieties in other regions. |
First Year Of Impact | 2022 |
Sector | Agriculture, Food and Drink |
Impact Types | Societal,Economic |
Description | EIT-Food Innovation grant |
Amount | € 1,039,143 (EUR) |
Funding ID | 21145 |
Organisation | European Commission |
Sector | Public |
Country | European Union (EU) |
Start | 01/2021 |
End | 12/2022 |
Description | Impact on sustainability, shelf-life and nutritional value by vertically farmed leafy greens via a new local supply chain |
Amount | € 729,415 (EUR) |
Organisation | European Union |
Sector | Public |
Country | European Union (EU) |
Start | 01/2020 |
End | 12/2020 |
Description | Personalised nutrition through kitchen gardens |
Amount | € 475,688 (EUR) |
Funding ID | PERNUG-21145 |
Organisation | Quadram Institute Bioscience |
Sector | Academic/University |
Country | United Kingdom |
Start | 01/2021 |
End | 12/2022 |
Title | Iron and zinc biofortified potatoes |
Description | Potato cultivars naturally high in iron and others naturally high in zinc have been identified within the International Potato Centre (CIP, Peru) germplasm collection and propagated to allow studies of their iron and zinc bioavailability |
Type Of Material | Biological samples |
Year Produced | 2019 |
Provided To Others? | No |
Impact | Identification of these biofortified cultivars has facilitated a human study to assess the bioavailability of the iron and of the zinc and their ability to improve micronutrient status in a population at high risk of being iron and zince deficient. The results will be reported iun due course. |
Description | Dr Erick Boy |
Organisation | HarvestPlus |
Country | United States |
Sector | Private |
PI Contribution | Human nutrition research industry, focusing on vitamins and minerals for public health. Expertise in DALYs analysis and in the implementation of biofortification programmes in developing countries/regions. |
Collaborator Contribution | Being a part of HarvestPlus nutrition research program, which encompasses food science and epidemiologic studies, Eric Boy provided expertise on the consumption, and efficacy of biofortified crops in Peru, how to effect the translation to regional/national scale, and in the generation and interpretation of models used in the DALYs analysis. |
Impact | The project progressed with the partner's insight and resulted in published articles and ideas on how to scale. |
Start Year | 2021 |
Description | Janet C King |
Organisation | University of California, Davis |
Department | UC Davis Health System |
Country | United States |
Sector | Hospitals |
PI Contribution | Using stable isotopes and kinetic modeling techniques, Dr. King´s research group studies how calcium and zinc utilization is affected by different physiological states, such as pregnancy, lactation, aging, or insufficient or excessive intakes. |
Collaborator Contribution | Dr King's expertise on stable isotopes proved important for the research study where zinc isotopes are used for meal preparation. |
Impact | The study finished successfully and resulted in a published research article. |
Start Year | 2021 |
Description | Kenneth H. Brown |
Organisation | University of California, Davis |
Country | United States |
Sector | Academic/University |
PI Contribution | Dr. Brown conducts research on the epidemiology, treatment, and prevention of childhood malnutrition in lower-income countries, including evaluation of large-scale intervention programs |
Collaborator Contribution | Dr Brown provided expertise zinc nutrition for the project. |
Impact | The project resulted in the publishing of a research article. |
Start Year | 2021 |
Description | Mineral analysis in plant foods |
Organisation | University of Nottingham |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | We have been developing biofortified potatoes (with Peruvian partners in the International Potato Centre) and biofortified leafy greens (EIT-Food project in Horizon Europe) and have been characterising these for the degree of biofortification. |
Collaborator Contribution | Our partners have been undertaking minerals analysis sing ICPMS of biofortified plants that we have developed ourselves or with collaborators. |
Impact | The mineral content data for our biofortified plant foods has allowed us to bid for and win additional funding from EIT-Food (Horizon Europe). |
Start Year | 2021 |
Description | Richard F. Hurrell |
Organisation | ETH Zurich |
Country | Switzerland |
Sector | Academic/University |
PI Contribution | Dr Hurrell extended his research area to the use of stable isotope techniques to measure mineral and trace element absorption in man, food factors influencing trace element and mineral absorption, food fortification, influence of diet and health (diabetes) and micronutrient (iron, iodine) deficiencies in the developing countries. |
Collaborator Contribution | Dr Hurrell provided expertise on iron biofortification |
Impact | The project resulted in a published research paper. |
Start Year | 2021 |
Title | Biofortified potatoes with relatively high bioavailability of the micronutrients |
Description | Iron biofortified potatoes and zinc biofortified potatoes |
Type | Products with applications outside of medicine |
Current Stage Of Development | Initial development |
Year Development Stage Completed | 2019 |
Development Status | On hold |
Impact | Too early. |
Description | International Clinical Trial Day |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | Local |
Primary Audience | Public/other audiences |
Results and Impact | International Clinical Trial Day |
Year(s) Of Engagement Activity | 2019 |
Description | YouTube Video about biofortification of potatoes in Peru and the benefits it can bring |
Form Of Engagement Activity | A broadcast e.g. TV/radio/film/podcast (other than news/press) |
Part Of Official Scheme? | No |
Geographic Reach | National |
Primary Audience | Public/other audiences |
Results and Impact | This video was prepared to highlight the important work going on at the International Potato Centre in Peru (CIP) and in the BBSRC GCRF project led by QIB with CIP, the Institute of Nutritional Investigation (IIN) in Peru and the ETH institute in Zurich, Switzerland. It is focused on the potential for these innovative high iron potato clones to reduce the incidence of anemia in Peru, but also could be of interest beyond Peru. Hundreds have watched the video and it will be further promoted as the GCRF project obtains results from the ODA-funding.. |
Year(s) Of Engagement Activity | 2021 |
URL | https://www.youtube.com/watch?v=pWRdUfWkE_s |