Biofortification of wheat is potentially a sustainable strategy to improve zinc intake; however, evidence of its effectiveness is needed. A household-based, double-blind, cluster-randomized controlled trial (RCT) was conducted in rural Pakistan. The primary objective was to examine the effects of consuming zinc-biofortified wheat flour on the zinc status of adolescent girls aged 10–16 years (n = 517). Households received either zinc-biofortified flour or control flour for 25 weeks; blood samples and 24-h dietary recalls were collected for mineral status and zinc intake assessment. Plasma concentrations of zinc (PZC), selenium and copper were measured via inductively coupled plasma mass spectrometry and serum ferritin (SF), transferrin receptor, alpha 1-acid glycoprotein and C-reactive protein by immunoassay. Consumption of the zinc-biofortified flour resulted in a moderate increase in intakes of zinc (1.5 mg/day) and iron (1.2 mg/day). This had no significant effect on PZC (control 641.6 ± 95.3 µg/L vs. intervention 643.8 ± 106.2 µg/L; p = 0.455), however there was an overall reduction in the rate of storage iron deficiency (SF < 15 µg/L; control 11.8% vs. 1.0% intervention). Consumption of zinc-biofortified flour increased zinc intake (21%) but was not associated with an increase in PZC. Establishing a sensitive biomarker of zinc status is an ongoing priority.

Background: Zinc-biofortified cereals are a promising strategy to combat zinc deficiency, though evidence on health outcomes is limited. This study assessed the effectiveness of consuming zinc-biofortified wheat flour on growth and zinc-related morbidity among adolescent girls (10–16 years; N = 517) and children (1–5 years; N = 517) living in rural north-west Pakistan. Methods: In this double-blind, cluster-randomised controlled effectiveness trial, 486 households received either zinc-biofortified or control wheat flour for 25 weeks. Anthropometric measurements and lung function tests (LFTs) were performed at the beginning, middle, and endline. Data on the incidence and duration of respiratory tract infection (RTI) and diarrhoea in the preceding two weeks were collected fortnightly. Analyses included baseline-adjusted linear mixed models for continuous outcomes and Pearson’s chi-square for categorical data. Results: At a zinc differential of 3.7 mg/kg for adolescent girls provided by zinc-biofortified wheat flour, the intervention had no significant effect on height or weight. For children, head circumference was significantly greater in the biofortified group at endline (control 48.47 ± 2.03 cm vs. intervention 48.76 ± 1.82 cm; p = 0.003), with no differences in other anthropometric parameters. Towards the end of the trial, a lower incidence of RTIs was reported in the intervention arm compared to the control arm for both children (week 26: control 27.4% vs. intervention 17.6%, p = 0.036) and adolescent girls (week 24: control 19.3% vs. intervention 11.5%, p = 0.037; week 26: control 14.5% vs. intervention 6.1%, p = 0.014). When the longitudinal prevalence (cumulative days of sickness as a percentage of total days) of RTI was considered, no treatment effects were observed. No benefits of treatment were reported for diarrhoea or LFT. Conclusions: The provision of zinc-biofortified wheat flour for 25 weeks did not have a significant effect on the growth of adolescent girls but modestly improved head circumference in children. Longer-term interventions are needed to monitor changes in functional outcomes with the national scale-up of zinc-biofortified wheat varieties.

Malnutrition is associated with reduced learning aptitude and growth during childhood. We examined the impact of providing two school lunch variants, a standard school meal (school feeding, n = 70), or the standard meal with additional micronutrients (school feeding + micronutrient powder (MNP), n = 70), in children attending two schools in northwest Pakistan. A third local government school, where no lunch was provided (no school feeding, n = 70), served as the control. The primary outcome, cognitive function, was assessed using the Raven’s Coloured Progressive Matrices (RCPM) test, alongside haemoglobin, at three-time points: T1 (baseline, before the initiation of the school lunch programme), T2 and T3 (5 and 12 months, respectively, after the introduction of the school lunch). Data were analysed using linear mixed-effects models to contrast between trial groups, the changes from T1 to T2 and T3. Adjusted for T1 and other co-variates, improvements in the RCPM scores were significantly greater in the school feeding group at T2 (b = 1.61, (95% CI = 0.71–2.52), t = 3.52, p = 0.001) and T3 (b = 1.28, (95% CI = 0.22–2.35), t = 2.38, p = 0.019) compared with no school feeding. In addition, at T2 (b = 1.63, (95% CI = −0.10–3.37), t = 1.86, p = 0.065), there were no significant differences between school feeding + MNP and no school feeding groups. However, improvements in the RCPM scores were significantly greater in the school feeding + MNP group at T3 (b = 2.35, (95% CI = 0.51–4.20), t = 2.53, p = 0.013) compared with no school feeding. The findings indicate an improvement in cognitive performance in children who received a school meal with and without MNP, over a 12-month period. Currently there is no operational school feeding programme at the national or provincial level in Pakistan. Our findings, therefore, highlight the need for school feeding programmes to improve learning opportunities for children from underprivileged communities.

Background/Objective: Zinc deficiency is common worldwide and has been linked to reduced growth and immune function, increased risk of and slower recovery from infections, and increased risk of non-communicable diseases. To address the issue, zinc biofortification of wheat has been proposed as a sustainable approach to increase dietary zinc intake in countries like Pakistan, where zinc deficiency rates are high and wheat is the primary staple crop. Since plasma zinc concentration (PZC) does not reliably respond to small changes in zinc intake, biomarkers sensitive to small changes in zinc intake achievable though biofortification are needed. Activity indices for zinc-dependent metabolic steps of desaturation and elongation of omega-6 fatty acids (FAs) have been proposed as sensitive zinc biomarkers. Oxylipin metabolites of polyunsaturated FAs may also respond to changes in zinc intake and further mediate metabolic response to oxidative stress. The objective of the current study was to assess the effects of consuming zinc-biofortified wheat flour on plasma markers of fatty acid (FA) metabolism in females aged 10–16 years. Methods: A nested secondary analysis was conducted in samples from a double-blind, cluster-randomized controlled trial conducted in rural Pakistan, whereparticipants (n = 517) consumed either zinc-biofortified wheat flour or control flour for 25 weeks. Total plasma FAs and oxylipins were measured by liquid chromatography tandem mass spectrometry (LC–MS/MS). Activity indices were estimated from the ratios of product to precursor FAs. Results: Except for docosahexaenoic acid (DHA, p < 0.05), no significant intervention effect was observed on plasma FAs and FA activity index endpoints. Zinc-biofortified wheat intake reduced pro-inflammatory oxylipins and biomarkers of oxidative stress, 5-HETE (p < 0.05), 9-HETE (p < 0.05), 11-HETE (p < 0.05), and 15-HETE (p < 0.05), compared with the control. However, after adjustment for multiple comparisons, none of the intervention effects remained significant. Conclusions: Further study of the responsiveness and specificity of plasma oxylipins to changes in zinc intake is warranted.

The World Health Organisation estimates that dietary zinc deficiency affects 31% of the global population, with rates as high as 73% in some low- and middle-income countries. Zinc biofortification of staple crops, such as maize in Guatemala and wheat in Pakistan has the potential to offer a sustainable, low-cost strategy to increase dietary zinc intake on a population scale. This chapter reviews the efficacy and effectiveness studies conducted with biofortified wheat and maize, exploring the strengths and weaknesses of this strategy alongside supplementation and food fortification. Biofortified cereals stand out, particularly due to their minimal behavior disruption, potential for sustainable scale-up and accessibility to vulnerable groups. Trials have demonstrated that consuming biofortified cereals can increase daily zinc intake by amounts ranging from 21% to 169% compared with consuming standard varieties. However, there is limited evidence regarding the translation of this increase into improved human health. Challenges stem from a high phytate intake, a major inhibitor of zinc absorption associated with plant-rich diets, and a lack of sensitive biomarkers to detect subtle changes in dietary zinc intake through biofortification. Mechanical methods such as micro-milling that aim to boost mineral bioavailability are being explored. Investigating novel biomarkers remains a priority for better monitoring of interventions to increase zinc intake. Functional indicators such as anthropometric data have generally failed to show measurable impacts from consuming biofortified foods, but there are some positive findings related to self-reported morbidities. Long-term interventions are recommended for tracking functional outcomes resulting from incremental zinc intakes through biofortification.