Effects of prolonged breastfeeding and colostrum fatty acids on allergic manifestations and infections in infancy

Background In developed countries World Health Organization recommendation of 6 months' exclusive breastfeeding is under debate. Objective We assessed the impact of predominant breastfeeding (PBF) duration and colostrum long-chain polyunsaturated fatty acids (LC-PUFAs) profile on the risk of allergic manifestations (wheezing and atopic eczema) and infections [low respiratory tract infections (LRTIs) and gastroenteritis] in infancy. Methods Information on child feeding practices was obtained from 580 infants of a pregnancy cohort. Presence of infant's health outcomes was documented through questionnaires at 6 and 14 months of age. The LC-PUFAs were measured in colostrum. Adjusted odds ratios (adjOR) and 95% confidence intervals (CI) were estimated using multivariable logistic regression models. Results In comparison with never breastfeeding, PBF for 4-6 months was associated with lower risk of wheezing (adjOR = 0.53; 95% CI, 0.32, 0.89), LRTIs (adjOR = 0.51; 95% CI, 0.31, 0.83) and atopic eczema (adjOR = 0.58; 95% CI, 0.32, 1.04) between months 7 and 14 of life. Results of a risk period-specific analysis (restricted to infants at risk for outcome onset after 6 months of age), showed no indication for reverse causation (results were not very different compared with an overall analysis). Predominantly breastfeeding for 4-6 months was associated with lower risk of gastroenteritis during the first 6 months of life (adjOR = 0.34; 95% CI, 0.18, 0.64). Among breastfed infants higher doses of arachidonic acid (AA), docosahexaenoic acid, and total n-3 in were associated with a decreased risk of gastroenteritis, but no association was found for allergic manifestations or LRTI. Conclusions and Clinical Relevance Promotion of PBF for 4-6 months could reduce the burden of allergic manifestations and infections in infancy. Beneficial effects of breastfeeding on gastroenteritis were explained in part by exposure to higher doses of n-3 and AA received from colostrum. No significant effects from fatty acid dose were found on risk of allergic manifestations or LRTIs.