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

Nutrition Journal

Research

Peter Curtis¹  Susan Fairweather-Tait¹  Asmaa Abdelhamid¹  Lee Hooper¹  Martin Falkingham¹  Louise Dye² 

[1] Diet and Health Group, School of Medicine, Health Policy and Practice, University of East Anglia, UK;Human Appetite Research Unit, Institute of Psychological Sciences, University of Leeds, UK;

关键词: Iron Deficiency;    Serum Ferritin;    Iron Deficiency Anaemia;    Cognitive Domain;    Intelligence Quotient;   

DOI  :  10.1186/1475-2891-9-4

 received in 2009-07-29, accepted in 2010-01-25,  发布年份 2010

来源: Springer

【 摘 要 】

BackgroundIn 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).AimTo assess whether iron supplementation improved cognitive domains: concentration, intelligence, memory, psychomotor skills and scholastic achievement.MethodologySearches 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.ResultsFourteen 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.ConclusionsThere 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.

【 授权许可】

Unknown   
© Falkingham et al; licensee BioMed Central Ltd. 2010. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.