Department of Health Promotion, Education, and Behavior, Arnold School of Public Health, University of South Carolina, Columbia, SC, USA; Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia; Department of Infectious Diseases at the Peter Doherty Institute, The University of Melbourne, Melbourne, Victoria, Australia.
Melbourne School of Psychological Sciences, The University of Melbourne, Melbourne, Victoria, Australia.
J Nutr. 2023 Jan;153(1):352-363. doi: 10.1016/j.tjnut.2022.12.026. Epub 2022 Dec 28.
Anemia and iron deficiency have been associated with poor child cognitive development. A key rationale for the prevention of anemia using supplementation with iron has been the benefits to neurodevelopment. However, little causal evidence exists for these gains.
We aimed to examine effects of supplementation with iron or multiple micronutrient powders (MNPs) on brain activity measures using resting electroencephalography (EEG).
Children included in this neurocognitive substudy were randomly selected from the Benefits and Risks of Iron Supplementation in Children study, a double-blind, double-dummy, individually randomized, parallel-group trial in Bangladesh, in which children, starting at 8 mo of age, received 3 mo of daily iron syrup, MNPs, or placebo. Resting brain activity was recorded using EEG immediately after intervention (month 3) and after a further 9-month follow-up (month 12). We derived EEG band power measures for delta, theta, alpha, and beta frequency bands. Linear regression models were used to compare the effect of each intervention with that of placebo on the outcomes.
Data from 412 children at month 3 and 374 at month 12 were analyzed. At baseline, 43.9% were anemic and 26.7% were iron deficient. Immediately after intervention, iron syrup, but not MNPs, increased the mu alpha-band power, a measure that is associated with maturity and the production of motor actions (iron vs. placebo: mean difference = 0.30; 95% CI: 0.11, 0.50 μV; P = 0.003; false discovery rate adjusted P = 0.015). Despite effects on hemoglobin and iron status, effects were not observed on the posterior alpha, beta, delta, and theta bands, nor were effects sustained at the 9-month follow-up.
The effect size for immediate effects on the mu alpha-band power is comparable in magnitude with psychosocial stimulation interventions and poverty reduction strategies. However, overall, we did not find evidence for long-lasting changes in resting EEG power spectra from iron interventions in young Bangladeshi children. This trial was registered at www.anzctr.org.au as ACTRN12617000660381.
贫血和缺铁与儿童认知发育不良有关。用铁补充剂预防贫血的一个主要理由是对神经发育有益。然而，这些益处的因果证据很少。
我们旨在使用静息脑电图（EEG）检查铁或多种微量营养素粉（MNP）补充对脑活动测量的影响。
本神经认知子研究纳入的儿童是从孟加拉国的儿童铁补充益处和风险研究中随机选择的，这是一项双盲、双模拟、个体随机、平行组试验，8 月龄的儿童接受为期 3 个月的每日铁糖浆、MNP 或安慰剂治疗。在干预后（第 3 个月）和进一步的 9 个月随访（第 12 个月）后立即使用 EEG 记录静息脑活动。我们得出了 delta、theta、alpha 和 beta 频带的 EEG 频带功率测量值。使用线性回归模型比较每种干预措施与安慰剂对结果的影响。
在第 3 个月和第 12 个月分析了 412 名儿童的数据。在基线时，43.9%的儿童贫血，26.7%的儿童缺铁。铁糖浆干预后，立即增加了 mu alpha 频带功率，这是与成熟和运动动作产生相关的指标（铁与安慰剂：平均差异=0.30；95%置信区间：0.11，0.50 μV；P=0.003；假发现率调整 P=0.015）。尽管对血红蛋白和铁状态有影响，但在后 alpha、beta、delta 和 theta 频带未观察到影响，在 9 个月的随访中也未观察到影响。
mu alpha 频带功率的即时影响的效应大小与心理社会刺激干预和减贫策略相当。然而，总的来说，我们没有发现铁干预对年轻孟加拉国儿童静息 EEG 功率谱的持久变化的证据。这项试验在 www.anzctr.org.au 注册，注册号为 ACTRN12617000660381。
