Systematic Review of Nutrients' Impact on Cognition and School Performance in School-Aged Children in Sub-Saharan Africa.

CONTEXT: Over the past few decades, numerous studies have reported significant associations between nutrient intake, cognition, and later academic achievement in school-aged children. Most of these studies were conducted in Western countries, with a limited number in sub-Saharan Africa (SSA).

OBJECTIVE

This study provides a systematic review of research exploring the links between nutrients and cognition and/or academic performance in SSA and proposes appropriate cognitive and academic performance assessments for future research in this area.

DATA SOURCES: Systematic searches were conducted in the Web of Science, HINARI, ScienceDirect, PsycINFO, PubMed, and Google Scholar databases, as well as in the reference lists of relevant publications, from January to June 2023.

DATA EXTRACTION: Data were manually extracted from included publications by independent reviewers and registered in predefined sheets.

DATA ANALYSIS: A total of 31 publications were included in this review. Of these, 11 assessed the relationship between nutrients and cognition and/or academic performance, and 14 and 6 reported on cognitive and academic assessment tests, respectively. Fortification-based interventions were generally more effective than multimicronutrient (MMN) supplementation (MMNS). Additionally, micronutrients including iron, zinc, iodine, riboflavin, vitamin B6, folate, and vitamin B12 demonstrated positive associations with cognition, whereas evidence for vitamin A, vitamin D, and omega-3 fatty acids remains inconclusive. Noteworthy, most of the included studies focused on micronutrients, and there is a lack of research on the potential impacts of other types of nutrients, such as complex lipids. Furthermore, the Raven's Coloured Progressive Matrices (RCPM) and academic performance assessment using school marks have been repeatedly used, with acceptable validity for the RCPM.

CONCLUSION

Cognitive and academic performance may be associated with specific micronutrients in school-aged children in SSA. The RCPM is a promising tool for assessing cognition in this population. Nevertheless, the findings remain inconclusive for MMNS and some nutrients, which further research may help elucidate.

SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration number: CRD42023392215.