From the Centre of Excellence for Nutrition, North-West University, Potchefstroom, South Africa (LM, CMS, and JB); the Human Development and Health Academic Unit, Faculty of Medicine, University of Southampton, Southampton, United Kingdom (PCC), the National Institute for Health Research Biomedical Research Centre in Nutrition, Southampton University Hospital National Health Service Foundation Trust and University of Southampton, Southampton, United Kingdom (PCC); the Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia (PCC); and the Laboratory of Human Nutrition, Institute of Food, Nutrition and Health, Eidgenössische Technische Hochschule Zürich, Switzerland (MBZ).
Am J Clin Nutr. 2015 Mar;101(3):668-79. doi: 10.3945/ajcn.113.081208. Epub 2014 Dec 31.
Although iron supplementation in malaria-free areas mostly reduces infectious morbidity, it can sometimes increase morbidity from infections as a result of the dependence of pathogenic microorganisms on iron. Supplementation with n-3 (ω-3) long-chain polyunsaturated fatty acids (LCPUFAs) improved morbidity in several human studies. However, information on the combined effect of iron and n-3 LCPUFA supplementation on infectious morbidity is limited.
We determined whether n-3 LCPUFAs and iron supplementation, alone or in combination, affected absenteeism and illness in iron-deficient schoolchildren with low fish intake.
A total of 321 South African children (aged 6-11 y) with iron deficiency (ID) were randomly divided into 4 groups to receive 1) iron plus placebo, 2) a mixture of docosahexaenoic acid and eicosapentaenoic acid (DHA/EPA) plus placebo, 3) iron plus DHA/EPA, or 4) placebo plus placebo as oral supplements 4 times/wk for 8.5 mo. Morbidity was recorded, and iron-status indexes were measured. The total phospholipid fatty acid composition of peripheral blood mononuclear cell membranes was analyzed in a subsample (n = 130).
Iron supplementation increased the number of days with illness when all symptoms were considered (B: 0.87; 95% CI: 0.71, 1.03) as well as illness that was specifically caused by respiratory symptoms (B: 1.45; 95% CI: 1.21, 1.70), whereas DHA/EPA reduced the number of days with illness at school (B: -0.96; 95% CI: -1.33, -0.59). The increases caused by iron were reduced to the levels seen in the placebo plus placebo group when iron was provided in combination with DHA/EPA as indicated by significant iron × DHA/EPA interactions (both P < 0.001).
Iron supplementation increased morbidity (mostly respiratory) in iron-deficient South African schoolchildren with low DHA/EPA intake, but when iron was given in combination with DHA/EPA, this effect was prevented.
尽管在无疟疾地区补充铁元素通常会降低传染性发病率，但由于致病微生物依赖铁元素，它有时也会增加感染性发病率。几项人体研究表明，补充 n-3（ω-3）长链多不饱和脂肪酸（LCPUFA）可以改善发病率。然而，关于铁和 n-3 LCPUFA 联合补充对传染性发病率的综合影响的信息有限。
我们旨在确定 n-3 LCPUFA 和铁单独或联合补充是否会影响低鱼类摄入量的缺铁学龄儿童的缺课和疾病。
共有 321 名南非儿童（年龄 6-11 岁）患有缺铁症（ID），他们被随机分为 4 组，分别接受 1）铁加安慰剂，2）二十二碳六烯酸和二十碳五烯酸（DHA/EPA）混合物加安慰剂，3）铁加 DHA/EPA，或 4）安慰剂加安慰剂，作为口服补充剂，每周 4 次，持续 8.5 个月。记录发病率，并测量铁状态指标。在一个亚样本（n=130）中分析外周血单个核细胞膜的总磷脂脂肪酸组成。
铁补充剂增加了所有症状考虑时的疾病天数（B：0.87；95%置信区间：0.71，1.03），以及由呼吸道症状引起的特定疾病天数（B：1.45；95%置信区间：1.21，1.70），而 DHA/EPA 减少了在校疾病天数（B：-0.96；95%置信区间：-1.33，-0.59）。当铁与 DHA/EPA 联合提供时，铁引起的增加减少到与安慰剂加安慰剂组相同的水平，这表明铁与 DHA/EPA 之间存在显著的相互作用（均 P<0.001）。
铁补充剂增加了南非缺铁学龄儿童（DHA/EPA 摄入量低）的发病率（主要是呼吸道疾病），但当铁与 DHA/EPA 联合使用时，这种作用得到了预防。
