Lack of influence of red palm oil on severity of malaria infection in pre-school Nigerian children

Abstract

Vitamin A supplements are reported to reduce febrile episodes of malaria and parasite counts, especially in children aged 12–36 months. Red palm oil (RPO) is a good source of vitamin A, is rich in α- and β-carotene and is as effective as high-dose retinyl palmitate supplements in improving vitamin A status. In western Nigeria, where malaria is endemic, RPO is widely used and consumption can be measured using plasma α-carotene as a proxy biomarker since there are few other prominent sources of this carotene in the diet. The influence of RPO consumption on malaria was investigated in 207 children (aged 0–60 months) who presented with fever in August–October 1999 at several hospital clinics around Ile-Ife. Medical and anthropometric data, body temperature, parasitaemia and plasma C-reactive protein (CRP), retinol, carotenoids and tocopherols were measured in the children. Mothers were interviewed on usage of cooking oil and mosquito nets in the home, education and occupation. Most families used RPO and median plasma concentrations of both α-carotene (0·518 μmol/L) and β-carotene (0·698 μmol/L) in the children were high. Using body temperature, parasite density and plasma CRP as markers of disease severity, multiple linear regression analysis was carried out on those for whom complete data were available ( n = 138), separated into 3 age-groups of < 12 months ( n = 37), 12–36 months ( n = 68) and > 36 months ( n = 33). In the absence of plasma retinol, plasma α-carotene explained 13·9% of the variance in parasite density ( P = 0·013) but only in children aged > 36 months. The relationship with disease severity was negative i.e., there was some evidence that RPO usage protected against malaria, and other dietary indices generally indicated that better nutritional status was associated with a lower severity of malaria.