From: Nutritional perspectives on sickle cell disease in Africa: a systematic review
Authors and year of publication | Location | Ages | No. of subjects | Intervention | Nutrient intervention type | Design | Outcome | Comments |
---|---|---|---|---|---|---|---|---|
Afolabi et al., 2012 [85] | Lagos State and Ogun State, Nigeria | 15–48 years | Not reported | Seed oils from Solenostemon monostachyus, Ipomoea involucrate and Carica papaya plants | Plant extract/ seed oil | In vitro comparisons using blood from SCD patients; comparison groups were controls, cells treated with glutathione, and cells treated with a known anti-sickling plant extract | • All plant extracts studied led to reduction in sickled red blood cells, reduction in Fe+ 2/Fe+ 3 ratios, and reduction in lactate dehydrogenase activity when compared with controls • Individual extracts also showed varying improvements in hemoglobin concentration, sickle cell polymerization inhibition, and catalase activity | Some gender dependent differences were noted; specific bioactive compounds within each plant extract were not isolated |
Imaga et al., 2013 [86] | Lagos State, Nigeria | 15–28 years | 4 (2 treated, 2 controls) | Oral ingestion for two weeks of a commercial product made from Cajanus cajan plant extract | Plant extract/ seed oil | Non-blinded in vitro comparison study | • Treatment group reported to have anti-sickling effect, but no statistical analyses performed • Treatment group reported to have increased fetal hemoglobin, but no statistical analyses performed • No effect reported on packed cell volume, hemoglobin, or mean corpuscular hemoglobin | Statistical analyses lacking for main outcomes |
Kaddam et al., 2019 [87] | Khartoum, Sudan | 5–42 years | 47 | Acacia Senegal (gum Arabic) supplementation as a lipid-lowering agent | Plant extract/ seed oil | Single-arm trial | Treatment led to significantly decreased total cholesterol, triglycerides, and low-density lipoprotein; no effect on high-density lipoprotein | Gum Arabic is a dried, gummy substance obtained from the acacia Senegal tree |
Adegoke et al., 2013 [88] | Ekiti State, Nigeria | 1 year to “adolescent” (upper range not specified) | 125 (65 treated, 60 controls) | Oral ingestion for 6 months of freshly squeezed lime juice; dose was weight- dependent (range: 10–30 ml daily) | Micronutrient | Open label, randomized study | • Treated group had significantly fewer pain episodes, febrile illness, and admission rate • Treated group had significantly increased mean hematocrit • No change in transfusion rate, organomegaly, or jaundice | Effect hypothesized to result from vitamin C, amino acids (especially phenylalanine) and flavonoids |
Adegoke et al., 2017 [67] | Ile-Ife, Nigeria | Mean age 7 years | 170 (95 treated, 75 controls) | Oral ingestion for 3 months of vitamin D supplementation in children with SCD that had low 25-hydroxyvitamin D (25-OHD) levels | Micronutrient | Age- and gender-matched controlled study | • Children with SCD and low 25-OHD levels had enhanced levels of pro-inflammatory cytokines • Treatment with vitamin D in children with SCD that had low 25-OHD levels led to an improved pro-inflammatory cytokine profile | Effect hypothesized to result from anti-inflammatory influence of supplemental vitamin D |
Daak et al., 2013 [89] | Khartou, Sudan | 2–24 years | 128 (67 treated, 61 controls) | Oral ingestion for 1 year of Omega-3 capsules containing EPA and DHA fatty acids; dose was weight-dependent | Macronutrient | Double-blinded, placebo-controlled, randomized study | • Treatment group had improved primary outcome: significantly fewer clinical vaso-occlusive events • Treatment group also had reduced severe anemia, reduced blood transfusions, reduced white blood cell counts, and reduced school absences due to disease • No change in rates of stroke, sequestration crisis, or vascular necrosis | The study was not powered to detect changes in rates of stroke, sequestration crisis, or vascular necrosis |
Cox et al., 2018 [90] | Dar-es-Salaam, Tanzania | 8–12 years (mean 10 years) | 119 | Oral ingestion of ready-to-use supplementary food (RUSF) with and without arginine and citrulline | Macronutrient | Double-blind, random order crossover trial | • RUSF increased the global arginine bioavailability ratio and improved measures of endothelial function, and led to improvements in growth • RUSF fortified with arginine and citrulline did not additionally increase the plasma global arginine bioavailability ratio or improve endothelial function | Arginine is the sole substrate of endothelial nitric oxide synthase and has been implicated in pathophysiology of SCD complications |
Onalo et al., 2019 [91] | Abu, Nigeria | 5–17 years (mean 11 years) | 68 (35 treated, 33 controls) | Oral arginine therapy every 8 h until discharge in SCD patients hospitalized with severe vaso-occlusive events | Macronutrient | Double-blind, randomized, phenotype included placebo-controlled trial | • Plasma arginine levels increased by 125% (arginine arm) vs 29% (placebo arm) • 54% of children treated with arginine were discharged compared to 24% in placebo arm by day 5 • Arginine treatment appeared to ameliorate some measures of pain • No significant differences in adverse events but arginine arm trended more towards vomiting compared to placebo | Arginine had previously been shown to have benefits in individuals with SCD in studies performed in the Unite States |