Nutritional Perspectives on Sickle Cell Disease in Africa: A Systematic Review

Abstract

Background: Sickle cell disease (SCD), an inherited blood disorder, predominantly affects individuals in sub-Saharan Africa. While there are established studies that links its pathophysiology and nutritional status, the extent of research in this area involving African patients has not been previously described. This systematic review aimed to assess the nutrition-focused landscape of SCD studies in Africa, summarize findings, and highlight gaps in knowledge that could inform priority-setting for future research.Methods: The study was conducted using the Preferred Reporting items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. We included all original studies, conducted between 1995 and 2018, on nutritional status of individuals with SCD in Africa. ‘Nutritional status’ was defined by studies on dietary intake, measurements of growth/anthropometry, and nutritional biomarkers. Studies of anemia in non-SCD individuals and those with sickle cell traits were excluded. Databases used were Ovid Embase, Medline, Biosis and Web of Science. Results: The search returned 366 articles from which 62 studies were included in the final analyses. Seventy percent of the investigations were conducted in Nigeria. Studies were categorized into one of three main categories: descriptive studies of anthropometric characteristics (50%), descriptive studies of macro- or micronutrient levels (35%), and interventional studies (15%). Findings consistently found growth impairment, especially among children and adolescents. Studies assessing macro- and micro-nutrients generally had small sample sizes and were exploratory in nature. Only two randomized placebo-controlled trials were identified, which measured the impact of fatty acid supplementation and lime juice on health outcomes. Conclusions: The findings reveal a moderate number of descriptive studies, with small sample size, that focused on various aspects of nutrition and sickle cell disease in African patients. There was a stark lack of interventional studies that could be used to inform evidence-based changes in clinical practice. Findings of investigations were generally consistent with data from other regional settings, describing a significant risk of growth faltering and malnutrition among individuals with SCD. There is an unmet need for clinical research to better understand the potential benefits of nutritional-related interventions for patients with SCD in sub-Saharan Africa in order to promote optimal growth and improve health outcomes.