Consumption of a Double-Fortified Salt Affects Perceptual, Attentional, andMnemonic Functioning in Women in a Randomized Controlled Trial in India

Abstract

Iron deficiency and iron deficiency anemia have been shown to have negative effects on aspects of perception, attention, and memory. The purpose of this investigation was to assess the extent to which increases in dietary iron consumption are related to improvements in behavioral measures of perceptual, attentional, and mnemonic function. Women were selected from a randomized, double-blind, controlled food-fortification trial involving ad libitum consumption of either a double-fortified salt (DFS) containing 47 mg potassium iodate/kg and 3.3 mg microencapsulated ferrous fumarate/g (1.1 mg elemental Fe/g) or a control iodized salt. Participants' blood iron status (primary outcomes) and cognitive functioning (secondary outcomes) were assessed at baseline and after 10 mo at endline. The study was performed on a tea plantation in the Darjeeling district of India. Participants ( = 126; 66% iron deficient and 49% anemic at baseline) were otherwise healthy women of reproductive age, 18-55 y. Significant improvements were documented for iron status and for perceptual, attentional, and mnemonic function in the DFS group (percentage of variance accounted for: 16.5%) compared with the control group. In addition, the amount of change in perceptual and cognitive performance was significantly ( < 0.05) related to the amount of change in blood iron markers (mean percentage of variance accounted for: 16.0%) and baseline concentrations of blood iron markers (mean percentage of variance accounted for: 25.0%). Overall, there was evidence that the strongest effects of change in iron status were obtained for perceptual and low-level attentional function. DFS produced measurable and significant improvements in the perceptual, attentional, and mnemonic performance of Indian female tea pickers of reproductive age. This trial was registered at clinicaltrials.gov as NCT01032005.

Iron Deficiency in Menstruating Adult Women: Much More than Anemia

“…After iron treatment, we detected an improvement in attention and working memory tests measured by Flanker and 2-back tasks, corroborating others' previous findings that show that cognitive alterations are responsive to iron administration. [46][47][48] Of note, there was a significant decrease in omission but not commission errors in 2-back. This is in line with studies reporting that these two types of errors have different correlates and, thus, may represent different processes.…”

Performance Factors Influencing Efficacy and Effectiveness of Iron Fortification Programs of Condiments for Improving Anemia Prevalence and Iron Status in Populations: A Systematic Review

“…As presented in Table 1, the most tested condiment, as a vehicle for efficacy or effectiveness of iron fortification, was salt. This fortification approach included 13 Double-fortified Salt (DFS) [21][22][23][24][25][26][27][28][29][30][31][32][33] and five Multiple Micronutrient Fortified Salt (MMFS) studies [34][35][36][37][38]. Only one study evaluated a seasoning powder [39], two studies evaluated fish sauce [40,41], and two studies evaluated soy sauce [42,43].…”

“…There were no efficacy or effectiveness studies of iron-fortified bouillon cubes. All studies were conducted in Asia or Africa using as subjects children or women of reproductive age during different time lengths using as fortificants a variety of iron forms that included micronized ground ferric pyrophosphate [21,30,33,38], encapsulated ferrous fumarate [21,31], ferrous fumarate [22], ferrous sulfate [23,28], microencapsulated ferrous fumarate [24], unknown iron source [25][26][27], ferrous sulfate monohydrate chelated with malic acid and sodium hexametaphosphate [29], ferrous sulfate hydrate encapsulated with partially hydrogenated vegetable oil [32], chelated ferrous sulfate [34][35][36][37], H-reduced elemental iron encapsulated with partially hydrogenated vegetable oil [39], ferrous sulfate citrate [40], or NaFeEDTA [40][41][42][43]. Blood hemoglobin was the main hematological indicator in all studies to evaluate the effect of iron fortification.…”

“…The full quality assessment table can be seen in Supplementary Materials Table S1. There were n = 12 studies classified as strong [21,24,[30][31][32][33]35,[38][39][40][41][42], n = 7 studies classified as moderate [22,26,28,29,36,37,43], and n = 4 studies classified as weak [23,25,27,34].…”

“…Effects sizes were estimated for each study, disaggregated by gender, age, iron source, and/or iron concentration when possible (Figure 2). Effect sizes were considered negligible if the standard deviation crossed the 0 x-axis, which was seen in nine studies [22,24,26,27,31,34,36,39,42]. Interestingly, Rajagopalan et al [26] demonstrated a negligible effect size for men, but a positive effect size for women, indicating that double-fortified salt may be a more effective treatment for women than men.…”