(P11-029-23) Biofortification With Zinc and Iron for Eliminating Deficiency in Pakistan: Effects on Plasma Markers of Fatty Acid Metabolism

Objectives: Plasma zinc concentration (PZC) is maintained over a wide range of dietary zinc intakes, and typically has little detectable response to the modest increases in zinc intake in food-based interventions. Therefore, there is interest in identifying functional biomarkers of zinc that are more responsive to zinc intake than PZC. Our primary objective was to evaluate changes in plasma markers of lipid metabolism in samples from the BiZiFED2 study of zinc biofortified wheat flour in Pakistan.

Methods: A panel of 24 plasma fatty acids (FA), total cholesterol, HDL and LDL cholesterol, and triglycerides were measured in plasma samples from 400 adolescent (10-16 y) females randomized to consume zinc biofortified wheat flour (ZBW, n=188) or control flour (Ctrl, n=212) for 25 weeks. Enzyme activity indices were determined at several steps of FA desaturation and elongation pathways, including FA desaturases 1 and 2 (FADS1 and FADS2), using the molar ratios of the product to precursor FA. In a random subsample of 100 participants (ZBW n=50, Ctrl n=50), a panel of 68 oxylipins was measured.

Results: At baseline 2 of the 24 FA, palmitoleic acid (C16:1n7) and dihomo-ƴ-linolenic acid (C20:3n6), were higher in Ctrl (p < 0.05). Zn intakes were 1.5 mg/d higher in those consuming ZBW vs. Ctrl, and had no significant effect on PZC. Except for docosahexaenoic acid (DHA, 22:6n3), no significant intervention effects (group*time interaction) on total, LDL, and HDL cholesterol, plasma FA, and FA activity index endpoints were observed. ZBW intake, however, increased plasma DHA vs. Ctrl (p < 0.05). Compared with Ctrl, ZBW intake also reduced the oxylipin products of 5- and 12/15-lipoxygenases, to include 5-HETE (p < 0.05), 11-HETE (p < 0.05), and 15-HETE (p < 0.05); and reduced the non-enzymatic oxidation product of arachidonic acid, 9-HETE (p < 0.05).

Conclusions: 25 weeks intake of zinc biofortified wheat flour shifted lipid essential FA metabolism towards the production of long chain omega-3 FA, and reduced pro-inflammatory oxylipin metabolites of arachidonic acid. These findings add to evidence demonstrating the sensitivity of lipid metabolic products in responding to small changes in dietary zinc intake in free living community settings.

Funding Sources: BBSRC Global Challenges Research Fund, Grant BB/S013989/1