Call for proposals to assess in humans Zinc and Iron absorption and bioavailability from common beans with low phytic acid using stable isotopes

  • Added Date: Thursday, 27 July 2023
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About HarvestPlus

At HarvestPlus, we believe that hidden hunger should not be inevitable for the people most at risk. We break down silos between agriculture and nutrition to develop creative solutions to combat hidden hunger. Our food-based approach targets some of the most vulnerable populations around the world. HarvestPlus, and its CGIAR partners, breed crops with naturally higher levels of key micronutrients, using a process called biofortification, as well as other beneficial agricultural traits, such as climate resilience, higher yields, disease resistance, and pest tolerance. This approach complements other nutrition interventions, and is evidence-based, cost-effective, and sustainable. We work across the entire value chain to develop and deliver nutrient-enriched seeds, grains, and foods to the people who need it most, via a large collection of innovative and traditional supply chain activities. HarvestPlus is a program of the International Food Policy Research Institute, a research center of the CGIAR, a global agricultural research partnership for a food secure future. Its science is carried out by its 15 research centers in collaboration with hundreds of partner organizations. To learn more about HarvestPlus, visit our home page here.

Background

Biofortification is an effective method to improve the nutritional content of crops and nutritional intake. Beans biofortified with micronutrients have shown improvement in iron intake in populations consuming it, which reduces iron deficiency (Hass et al., 2016). Another approach to reduce iron/zinc deficiency in populations is to increase the absorption of iron/zinc in non-biofortified (or biofortified) beans. Phytic acid is an important inhibitor of mineral absorption in humans. Reduction of phytic acid in beans improves absorption of iron in beans (Petry et al., 2013), but a milder reduction (1536 mg/d compared to 2253 mg/d) of phytic acid in maize did not affect zinc absoprtion (Mazariegos et al., 2006). The study in maize showed no differences between low phytic acid (lpa) and regular maize, however the reduction in phytic acid was around 65% (Mazariegos et al., 2006). Lpa beans have up to 90% lower phytic acid content compared to conventional beans (Hummel et al., 2020). Polyphenols reduce iron absorption in vitro using caco-2 cells (Hart et al., 2019). Lines of lpa beans with acceptable yield are available, but before further developing or promoting any lpa bean, a study to understand its physicochemical characteristics and potential iron/zinc absorption is needed to estimate the extent of their benefit. Also, genotypes (yellow beans) with polyphenolic profiles that are associated with higher iron absorption are consumed in some countries.

To guide plant breeding efforts to enhance the contents and bioavailability of iron and zinc in common beans (P. vulgaris), it is important to assess the absorption of the zinc and iron found in recently developed beans with low phytic acid content (<2 mg/100g) and contrasting polyphenolic profiles. HarvestPlus seeks to contract a research institution to conduct a clinical trial using stable isotopes to assess the absorption of zinc and iron in young adult (19-24 years) women who eat beans regularly and are at risk of inadequate zinc and iron intake.

The results of the study will address these primary research questions on zinc absorption:

What is the total and fractional zinc absorbed from beans with low phytic acid when consumed after boiling, broth included, as part of a meal with low phytic acid, with >50% of total phytic acid of the meals derived from the beans; What is the total and fractional zinc absorbed from beans with low phytic acid and low polyphenolic content when consumed after boiling, broth included, in a diet with low phytic acid, with >50% of total phytic acid of the meals derived from the beans; and How do the physicochemical attributes of the bean varieties/lines to be used affect zinc absorption?

The same questions should be addressed for iron bioavailability if resources permit.

The study should also carry out the following measurements in each of the varieties/lines of raw and cooked beans to be used in the absorption study:

The concentration of the minerals relevant to the objective of the study (iron, zinc, and calcium); The concentrations of phytic acid, phenolic acids, and polyphenols relevant to iron and zinc absorption; The sugar profile; The grain cooking time; The starch and protein digestibility; and Pasting properties

The applicants are encouraged to register the study protocol in the national, regional, or international clinical trial registry of their choice prior to initiating data collection.

Timeline

The project field and laboratory work should be completed within 4 months of awarding the contract and all reports are to be submitted prior to the end of 2 months from the completion of field work. Publication of results in peer-reviewed journals may occur thereafter. Project timelines and milestones will be identified clearly in the proposal submitted by the applicant.

Work plan and proposal submission - August 10, 2023 Expected start of study - September 30, 2023 Expected end of field study - February 15, 2024 Final technical report - March 15, 2024

Proposal

Firstly, reach out to Katie Foley (k.foley@cgiar.org) with an expression of intent in order to receive a workplan and budget template. Please submit the research protocol (proposal) with the workplan and budget on the IFPRI website. Key sections of the protocol are described below:

Ethics

It will be the responsibility of the principal investigator to obtain approval from the appropriate ethics/institutional review board (IRB) prior to the to the initiation of any contact with study subjects. The IRB process will be required before the awarding of the contract is completed. Funds will not be advanced until the IRB approval letter has been submitted, except when the project activities are separated into preparatory and implementation phases, in which case funding may be disbursed for the former phase only.

Local Partner (if applicable)

The local partner should be a well-established legal entity in the country where the study will take place who may form partnerships and/or a consortium with other entities within or outside the country to provide the necessary expertise and resources to carry out the project. HarvestPlus will contract directly with the lead institution in a consortium or partnership and that institution will be responsible for the dealings with the other parties. The recipient institutions will be required to submit copies of their corporate documents prior to the awarding of a contract.

Research Group Qualifications

The CVs of each lead researcher (including local partners) shall be submitted with the RFP. The CVs should clearly illustrate the researchers' qualifications, publications, expertise, and experience in relation to the component of the project that he/she will be responsible for, and copies of or references for all relevant peer-reviewed publications by the researchers, demonstrating expertise in all aspects of mineral absorption/bioavailability research using stable isotopes in humans.

Project Study Site(s)

The study site will be at the discretion of the research team.

Other Items to be Included in the Proposal

Title page with main investigator coordinates and reference research center Background information demonstrating in-depth understanding of the request for proposals and the subject matter of the research under consideration Focused literature review Study aim and specific objectives Description of the main and secondary outcomes, sample size calculation for primary and secondary outcomes, study design, selection and exclusion of subjects, methodology (including but not limited to grain importation/shipping, food preparation, isotopic labeling methods, laboratory analytical methods and QA/QC procedures, data collection and handling methods), and data analysis plan GANTT chart for study timeline Other relevant aspects critical for the success of the study

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