There are barriers to in-depth memory-based dietary assessment techniques in community-based research. Food pattern modeling may be an alternative method to traditional assessment techniques. The objective of this study was to pilot a comparison of food pattern modeling to 24 h diet recalls for predicting hematological outcomes of iron status. Data from 3–24 h dietary recalls in 27 women were analyzed by two methods: mean dietary intake estimates or food pattern modeling. Food pattern modeling was used to determine the total inventory of foods consumed with iron, phytate, or ascorbic acid or iron–phytate ratios. Each variable was analyzed for its relationship to hemoglobin, ferritin, and acute iron absorption from a meal challenge study by creating receiver operating characteristic (ROC) curves. There were no differences in ROC curves or diagnostic accuracies between food pattern modeling or mean dietary intake estimates for iron, vitamin C, phytate, or phytate–iron ratios for estimating hemoglobin or ferritin values (p > 0.05). Food pattern modeling was inferior to mean dietary estimates for acute iron absorption, suggesting that more detailed methods may be necessary for studies with sensitive or acute dietary measurement outcomes. Food pattern modeling for total iron, vitamin C, phytate, and phytate–iron ratios may be comparable to detailed memory-based recalls for larger studies assessing the impact of foods on iron status.
Objectives Phytic acid is an inhibitor of iron bioavailability, but recent research has suggested that individuals may adapt to phytic acid, and that the salivary protein, cystatin SN, may play a role. Study objectives were: 1) to assess the relationship between cystatin SN levels and iron bioavailability during a phytic acid rich meal, and 2) whether cystatin SN would differ among participants with greater vs. lower iron bioavailability overall. Methods Three groups of ten women received meals with: 1) 500 mg phytic acid powder sprinkles 2) 500 mg phytic acid capsules, or 3) no phytic acid. Meals included 18 mg iron. Pre-meal, hemoglobin, iron, ferritin, total iron binding capacity, transferrin saturation, and C - reactive protein were measured from venous blood. Iron bioavailability was measured by the mealtime percentage of maximum iron recovery (% max iron absorption); cystatin SN was measured pre-and post-meal by enzyme-linked immunosorbent assay. All participants completed 3–24 hour dietary recalls. Data were analyzed by multifactor regression analysis and ANOVA. Results There were no significant differences in group dietary intake (P > 0.05). The % max iron absorption was not different among groups; after adjustment, there was significantly greater % max iron absorption in Groups 2 and 3, compared to 1 (P = 0.03, P = 0.004, respectively). Unadjusted pre-to-post meal cystatin SN levels were significantly and positively correlated with improved iron bioavailability in Group 1 (P = 0.046, R2 = 0.4), but not Groups 2 or 3. After adjusted modeling, pre-to-post meal cystatin SN was significantly associated with improved % max iron absorption in Groups 1 and 2 (P's < 0.0001). Overall, there were significantly greater pre-to-post meal cystatin SN levels in participants with % max iron absorption greater, compared to less than 12% (10.2 ± 20.6 vs. −20.5 ± 13.5, respectively, P = 0.01). Conclusions There was a significant relationship between improved iron bioavailability and pre-to-post meal Cystatin SN levels with phytic acid rich meals. Overall, participants with greater meal iron bioavailability had significantly greater pre-to-post meal cystatin SN recovery. Cystatin SN may be a physiological factor in predicting iron bioavailability with phytic acid rich meals. Funding Sources Funded by Wichita State University's School of Nursing.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.