Determination of omega-3 long chain polyunsaturated fatty acid levels using dried blood spots in Zimbabwean children aged 7 to 9 years

Abstract

Background: Blood omega-3 long chain-polyunsaturated fatty acids (LC-PUFAs) have been widely studied in children because of the benefits from optimum physical and mental development. Despite these recognized benefits, the levels of blood omega-3 LC-PUFAs are unknown in Zimbabwean children. Omega-3 LC-PUFA levels were determined and reference intervals were established for the 7-9 year old Zimbabwean children. The association between omega LC-PUFAs and cognitive outcomes was also determined. Methods: A cross sectional study was conducted from September 2011 to August 2012 on a cohort of peri-urban Zimbabwean children aged 7-9 years born to mothers enrolled at late pregnancy into an HIV prevention program between 2002 and 2004. Whole dried blood spots were sampled and LC-PUFAs were quantified using gas liquid chromatography. Differences in LC-PUFAs between groups were compared using the Kruskal Wallis test. Spearman correlation coefficient was used for the relationship between LC-PUFA levels and cognitive development. Results: LC-PUFAs levels were determined in 297 Zimbabwean children of whom 170 (52%) were girls. The LC-PUFAs (wt/wt) ranges were; EPA 0.06–0.55%, DPA 0.38–1.98%, DHA 1.13–3.52%, ARA 5.58–14.64% and ARA: EPA ratio 15.47–1633.33. There were no gender differences in omega-3 LC-PUFAs levels (all p>0.05). EPA was statistically significantly elevated in the 8 years age group compared to those aged 7 and 9 years (0.20 vs 0.17 vs 0.18, respectively, p=0.049). ARA:EPA ratio was statistically significantly elevated in the 7 years age group compared to those aged 8 and 9 years (64.38 vs 56.43 vs 55.87 respectively, p=0.014). Conclusions: In this cohort of children, lower EPA levels and higher ARA:EPA ratios were observed compared to those reported in apparently healthy children elsewhere. The high ARA:EPA ratios make the children vulnerable to inflammatory pathologies. Identification and incorporation into diet of locally available foodstuffs rich in omega-3 LC-PUFAs is recommended as is as omega-3 supplementation.