Long-chain omega-3 polyunsaturated fatty acids in relation to gut integrity, growth and cognitive development of rural African children

Background and rationale: Weaning foods fed to infants in rural Gambia are often contaminated, resulting in infections which contribute to initiating a persistent inflammation of the gut. This enteropathy, which causes intestinal damage and malabsorption, is strongly associated with the high degree of growth faltering seen in Gambian infants. There is evidence that supplementary omega-3 long-chain polyunsaturated fatty acids (n-3 LCPs) might ameliorate this damage by reducing gastro-intestinal inflammation. Additionally, n-3 LCPs have been shown to benefit mental development and problem-solving ability in infants, but this has not yet been tested in an African population. Methods: A randomised, double-blind, controlled trial (500mg combined n-3 LCPs per day for six months) was conducted in a population of rural African infants aged 3 months - 9 months. The primary outcomes were infant anthropometric indicators and gut integrity (measured by urinary lactulose-mannitol ratios). Plasma fatty acid status (plasma fatty acid profiles), cognitive development (Willatts Test and an attention assessment at 12 months of age), intestinal mucosal inflammation (faecal calprotectin), and daily morbidities were the secondary outcome measures. Results: One-hundred and seventy-two Gambian infants completed the trial. Except for an increase in mid-upper-arm circumference z-scores in the intervention group (95% Cl: 0.06,0.56; p=0.017), no significant differences between treatment groups were detected for growth and lactulose-mannitol ratios at 9 months. At 12 months mid-upper-arm circumference remained greater in the intervention group, and significant increases in skinfold thicknesses were detected (pSO.022 for ali). Supplementation resulted in a significant increase in plasma n-3 LCP levels (p<O.001) and decrease in n-6 LCP:n-3 LCP ratios (p<O.OOl). Plasma n-6 fatty acid levels were not affected. No difference was detected for the other secondary outcomes. Conclusion: Fish oil supplementation proved safe and successfully increased plasma n-3 fatty acid status, but the results of this trial do not support the use of supplementary n-3 LCPs in young, breast-fed, rural Gambian infants for improving overall growth performance, intestinal integrity, and cognitive development, or reducing intestinal and systemic inflammation