Essential fats: how do they affect growth and development of infants and young children in developing countries? A literature review

Omega-3 and omega-6 fatty acids, particularly docosahexaenoic acid (DHA), are known to play an essential role in the development of the brain and retina. Intakes in pregnancy and early life affect growth and cognitive performance later in childhood. However, total fat intake, alpha-linolenic acid (ALA) and DHA intakes are often low among pregnant and lactating women, infants and young children in developing countries. As breast milk is one of the best sources of ALA and DHA, breastfed infants are less likely to be at risk of insufficient intakes than those not breastfed. Enhancing intake of ALA through plant food products (soy beans and oil, canola oil, and foods containing these products such as lipid-based nutrient supplements) has been shown to be feasible. However, because of the low conversion rates of ALA to DHA, it may be more efficient to increase DHA status through increasing fish consumption or DHA fortification, but these approaches may be more costly. In addition, breastfeeding up to 2 years and beyond is recommended to ensure an adequate essential fat intake in early life. Data from developing countries have shown that a higher omega-3 fatty acid intake or supplementation during pregnancy may result in small improvements in birthweight, length and gestational age based on two randomized controlled trials and one cross-sectional study. More rigorous randomized controlled trials are needed to confirm this effect. Limited data from developing countries suggest that ALA or DHA supplementation during lactation and in infants may be beneficial for growth and development of young children 6-24 months of age in these settings. These benefits are more pronounced in undernourished children. However, there is no evidence for improvements in growth following omega-3 fatty acid supplementation in children >2 years of age.