The effects of oral iron supplementation on cognition in older children and adults: a systematic review and meta-analysis

被引:179
作者
Falkingham, Martin [1 ]
Abdelhamid, Asmaa [1 ]
Curtis, Peter [1 ]
Fairweather-Tait, Susan [1 ]
Dye, Louise [2 ]
Hooper, Lee [1 ]
机构
[1] Univ E Anglia, Sch Med Hlth Policy & Practice, Diet & Hlth Grp, Norwich NR4 7TJ, Norfolk, England
[2] Univ Leeds, Inst Psychol Sci, Human Appetite Res Unit, Leeds LS2 9JT, W Yorkshire, England
关键词
QUALITY-OF-LIFE; ZINC SUPPLEMENTATION; DEFICIENCY ANEMIA; PERFORMANCE; ACHIEVEMENT; GROWTH; MEMORY; HEALTH; TRIAL;
D O I
10.1186/1475-2891-9-4
中图分类号
R15 [营养卫生、食品卫生]; TS201 [基础科学];
学科分类号
100403 ;
摘要
Background: In observational studies anaemia and iron deficiency are associated with cognitive deficits, suggesting that iron supplementation may improve cognitive function. However, due to the potential for confounding by socio-economic status in observational studies, this needs to be verified in data from randomised controlled trials (RCTs). Aim: To assess whether iron supplementation improved cognitive domains: concentration, intelligence, memory, psychomotor skills and scholastic achievement. Methodology: Searches included MEDLINE, EMBASE, PsychINFO, Cochrane CENTRAL and bibliographies (to November 2008). Inclusion, data extraction and validity assessment were duplicated, and the meta-analysis used the standardised mean difference (SMD). Subgrouping, sensitivity analysis, assessment of publication bias and heterogeneity were employed. Results: Fourteen RCTs of children aged 6+, adolescents and women were included; no RCTs in men or older people were found. Iron supplementation improved attention and concentration irrespective of baseline iron status (SMD 0.59, 95% CI 0.29 to 0.90) without heterogeneity. In anaemic groups supplementation improved intelligence quotient (IQ) by 2.5 points (95% CI 1.24 to 3.76), but had no effect on non-anaemic participants, or on memory, psychomotor skills or scholastic achievement. However, the funnel plot suggested modest publication bias. The limited number of included studies were generally small, short and methodologically weak. Conclusions: There was some evidence that iron supplementation improved attention, concentration and IQ, but this requires confirmation with well-powered, blinded, independently funded RCTs of at least one year's duration in different age groups including children, adolescents, adults and older people, and across all levels of baseline iron status.
引用
收藏
页数:16
相关论文
共 53 条
[1]  
[Anonymous], 2002, The Oxford Concise Colour Medical dictionary
[2]  
[Anonymous], COCHRANE DATABASE SY
[3]   Maternal iron deficiency anemia affects postpartum emotions and cognition [J].
Beard, JL ;
Hendricks, MK ;
Perez, EM ;
Murray-Kolb, LE ;
Berg, A ;
Vernon-Feagans, L ;
Irlam, J ;
Isaacs, W ;
Sive, A ;
Tomlinson, M .
JOURNAL OF NUTRITION, 2005, 135 (02) :267-272
[4]   Pre- and postweaning iron deficiency alters myelination in Sprague-Dawley rats [J].
Beard, JL ;
Wiesinger, JA ;
Connor, JR .
DEVELOPMENTAL NEUROSCIENCE, 2003, 25 (05) :308-315
[5]  
BEGH C, 2004, AM J MED, V116, pA7
[6]   Micro-nutrient supplementation and the intelligence of children [J].
Benton, D .
NEUROSCIENCE AND BIOBEHAVIORAL REVIEWS, 2001, 25 (04) :297-309
[7]   CELL-MEDIATED-IMMUNITY IN IRON-DEFICIENT AND VITAMIN-DEFICIENT CHILDREN [J].
BHASKARAM, C ;
REDDY, V .
BMJ-BRITISH MEDICAL JOURNAL, 1975, 3 (5982) :522-522
[8]   Randomised study of cognitive effects of iron supplementation in non-anaemic iron-deficient adolescent girls [J].
Bruner, AB ;
Joffe, A ;
Duggan, AK ;
Casella, JF ;
Brandt, J .
LANCET, 1996, 348 (9033) :992-996
[9]  
BRUNER AB, 1995, AM FAM PHYSICIAN, V52, P249
[10]  
Cohen J., 1988, Statistical power analysis for the behavioral sciences, VSecond