Samuel Scott

The Impact of Anemia on Child Mortality: An Updated Review

Iron deficiency anemia and child mortality are public health problems requiring urgent attention. However, the degree to which iron deficiency anemia contributes to child mortality is unknown. Here, we utilized an exhaustive article search and screening process to identify articles containing both anemia and mortality data for children aged 28 days to 12 years. We then estimated the reduction in risk of mortality associated with a 1-g/dL increase in hemoglobin (Hb). Our meta-analysis of nearly 12,000 children from six African countries revealed a combined odds ratio of 0.76 (0.62–0.93), indicating that for each 1-g/dL increase in Hb, the risk of death falls by 24%. The feasibility of a 1-g/dL increase in Hb has been demonstrated via simple iron supplementation strategies. Our finding suggests that ~1.8 million deaths in children aged 28 days to five years could be avoided each year by increasing Hb in these children by 1 g/dL.

Iron Status Is Associated with Performance on Executive Functioning Tasks in Nonanemic Young Women

BACKGROUND Iron deficiency (ID) is prevalent, particularly among women of reproductive age (WRA). How mild ID without anemia relates to cognition is poorly understood. Executive functioning (EF) has emerged as potentially being affected by mild ID in WRA. OBJECTIVE We sought to examine how iron markers relate to performance on EF tasks in nonanemic WRA. METHODS Participants included 127 females aged 18-35 y. Hematological indicators included hemoglobin, RBC distribution width, transferrin saturation (TSAT), ferritin, transferrin receptor (TfR), and total body iron (TBI). EF was assessed using 5 tasks. Associations between EF outcomes and iron status were examined using continuous iron predictors and group comparisons. RESULTS Better iron status was associated with better attention [faster reaction time (RT) with lower TfR (P = 0.028) and higher TSAT (P = 0.013)], inhibitory control [lower RT variability with higher TSAT (P = 0.042) and planning ability (faster planning time and a smaller planning time increase with increasing difficulty with higher ferritin; P = 0.010)]. No associations with iron status were found for several EF outcomes, possibly due to performance ceilings. Paradoxically, worse performance on a working memory task was related to better iron status, which may reflect hippocampal-frontal interference [lower capacity with lower TfR (P = 0.034) and higher TBI (P = 0.043) and a larger accuracy change with increasing difficulty with higher TBI (P = 0.016)]. Longer RTs on a working memory task were observed among those with positive TBI (iron surplus; P = 0.021) and <2 abnormal iron markers (P = 0.013) compared with those with negative TBI (iron deficit) and ≥2 abnormal markers, respectively. CONCLUSIONS These findings suggest cognitive ramifications of mild ID in otherwise healthy WRA and have implications for daily well-being. Future investigators should explore how brain system interactions change according to iron availability.

Cardiorespiratory Fitness is Associated with Better Executive Function in Young Women

PURPOSE A positive association between cardiorespiratory fitness (CRF) and cognitive function has been demonstrated mainly in children and older adults. Women attending college live in a cognitively demanding setting where optimal cognition matters but often experience declines in CRF. Our aim was to test whether CRF is associated with executive function in young adult women. METHODS Participants in this cross-sectional study included 120 healthy women age 18-35 yr in a university setting. Each woman completed a maximal treadmill-based exercise test to determine peak oxygen uptake (V˙O2peak), computerized tests of executive function, and questionnaires to assess motivation and other factors with potential to influence physical and cognitive performance. RESULTS Overall CRF was excellent, with a sample mean V˙O2peak of 44.6 mL·min·kg. After adjusting for covariates, higher V˙O2peak was associated with better performance on attention (P < 0.01), learning/shifting (P < 0.01), working memory (P < 0.01), and problem-solving (P < 0.05) tasks. Likewise, when women were grouped according to the American College of Sports Medicine fitness classification, performance on executive function tasks was poorest in women with very poor or poor CRF. Women with superior CRF performed best on executive function tasks, and performance was intermediate in women with fair, good, or excellent CRF. CONCLUSION The findings from this cross-sectional study suggest that optimal cognition is related to CRF in young adult women. Future studies are needed to test whether strategies to improve CRF are effective in improving cognitive function.

Combined iron deficiency and low aerobic fitness doubly burden academic performance among women attending university

BACKGROUND Academic success is a key determinant of future prospects for students. Cognitive functioning has been related to nutritional and physical factors. Here, we focus on iron status and aerobic fitness in young-adult female students given the high rate of iron deficiency and declines in fitness reported in this population. OBJECTIVES We sought to explore the combined effects of iron status and fitness on academic success and to determine whether these associations are mediated by cognitive performance. METHODS Women (n = 105) aged 18-35 y were recruited for this cross-sectional study. Data were obtained for iron biomarkers, peak oxygen uptake (VO2peak), grade point average (GPA), performance on computerized attention and memory tasks, and motivation and parental occupation. We compared the GPA of groups 1) with low compared with normal iron status, 2) among different fitness levels, and 3) by using a combined iron status and fitness designation. Mediation analysis was applied to determine whether iron status and VO2peak influence GPA through attentional and mnemonic function. RESULTS After controlling for age, parental occupation, and motivation, GPA was higher in women with normal compared with low ferritin (3.66 ± 0.06 compared with 3.39 ± 0.06; P = 0.01). In analyses of combined effects of iron status and fitness, GPA was higher in women with normal ferritin and higher fitness (3.70 ± 0.08) than in those with 1) low ferritin and lower fitness (3.36 ± 0.08; P = 0.02) and 2) low ferritin and higher fitness (3.44 ± 0.09; P = 0.04). Path analysis revealed that working memory mediated the association between VO2peak and GPA. CONCLUSIONS Low iron stores and low aerobic fitness may prevent female college students from achieving their full academic potential. Investigators should explore whether integrated lifestyle interventions targeting nutritional status and fitness can benefit cognitive function, academic success, and postgraduate prospects.

Consumption of Iron-Biofortified Beans Positively Affects Cognitive Performance in 18- to 27-Year-Old Rwandan Female College Students in an 18-Week Randomized Controlled Efficacy Trial

Background: Evidence shows that iron deficiency in adulthood may affect cognitive performance, possibly by disrupting neurotransmitter regulation or brain energy metabolism. Women of reproductive age (WRA) are among those who are most vulnerable to iron deficiency; however, they have been largely ignored in the literature relating iron status to cognition. Objective: Our aim was to determine the efficacy of iron-biofortified beans in improving cognition in WRA compared with control beans. Methods: A double-blind, randomized intervention study was conducted in 150 women aged 18–27 y with low iron status (ferritin <20 μg/L). Women were randomly assigned to consume iron-biofortified beans (86.1 ppm iron) or control beans (50.1 ppm iron) daily for 18 wk. Iron status was assessed based on hemoglobin, ferritin, transferrin receptor, and body iron values and on cognitive performance on 5 computerized tasks at baseline and endline. Results: Groups did not differ on any variables at baseline. Per protocol analyses revealed that consumption of the biofortified beans resulted in a 17% larger improvement in the speed of spatial selective attention; a nearly 7-fold larger improvement in the speed, a 68% greater improvement in the efficiency, and a >2-fold greater improvement in the specificity of memory retrieval; and a >2-fold larger improvement in the speed and a >3-fold larger improvement in the efficiency of memory search—all of which are relative to consumption of the control beans (P < 0.01 for all comparisons). Conclusions: Cognitive performance is sensitive to iron status, and consumption of iron-biofortified beans for 18 wk improved cognitive performance, especially the efficiency of search and the speed of retrieval on memory tasks, in young adult women. This trial was registered at clinicaltrials.gov as NCT01594359.

Iron status at opposite ends of the menstrual function spectrum

OBJECTIVES Although exercising women are at high risk of poor iron status, it is unknown how non-pathological, physiological menstrual function affects iron status. As such, this study investigates the association between menstrual function and iron status in exercising women with amenorrhea and exercising women with ovulatory, eumenorrheic menstrual cycles. DESIGN Cross-sectional analysis of iron depletion prevalence, iron status indices, exercise parameters, and diet composition. METHODS Women aged 18-35 years performing at least 2 h per week of aerobic exercise were recruited. Women with amenorrhea (AMEN) were defined by the absence of menses for at least 90 days or less than 6 menses in the past 12 months (n = 82). Women with ovulatory, eumenorrheic menstrual cycles (OvEU) were defined by the presence of ovulatory cycles of 26-35 days in length for the past 6 months (n = 109). Group differences in serum ferritin (Ft), soluble transferrin receptor (sTfR), total body iron (TBI), hemoglobin (Hb), hematocrit (Hct), iron depletion prevalence (Ft <15 μg/L), peak oxygen consumption (VO2peak), exercise minutes per week, and diet logs were assessed. RESULTS The prevalence of iron depletion was greater in OvEU when compared to AMEN (26% vs. 15%, p = 0.04). No significant differences were observed between AMEN and OvEU in Ft (30.2 ± 2.2 vs. 24.9 ± 2.6 μg/L; p = 0.62), sTfR (5.2 ± 1.4 vs. 4.9 ± 1.5 mg/L; p = 0.95), TBI (5.3 ± 2.7 vs. 4.8 ± 3.7 mg/kg; p = 0.42), Hb (13.2 ± 0.4 vs. 13.4 ± 0.6 g/dL; p = 0.80), Hct (39.5 ± 0.8% vs. 39.8 ± 4.1%; p = 0.93), or exercise parameters. AMEN consumed more vitamin C than OvEU (269 ± 180 vs. 129 ± 141 mg/day, p < 0.001), but all other dietary factors were similar between AMEN and OvEU. CONCLUSION Exercising women with ovulatory, eumenorrheic cycles are at a greater risk of iron depletion than exercising, amenorrheic women. Thus, menstrual function must be considered when screening for poor iron status in exercising women.