Eating salmon while pregnant can affect a mother’s breast milk
Mothers who eat more salmon before giving birth boost levels of a vital nutrient in their breast milk, but could lower levels of disease-fighting antibodies they pass on while feeding their baby, researchers have found.
Long-chain omega-3 fatty acids, found in oily fish such as salmon, are crucial during early childhood when they are needed for optimal growth and development. As well as being important for the growth of a baby's brain and eyes, they may also help the development of healthy blood vessels, heart, and immune system. As a result, pregnant women are encouraged to eat one or two servings a week of certain kinds of oily fish known to provide high levels of omega-3.
However, very little is known about the influence of eating oily fish during pregnancy on the omega-3 fatty acid content of the mother's milk, and on immune substances, such as the antibodies passed from mother to baby during breastfeeding. The protection against infection that this provides to vulnerable newborns is one of the reasons why breastfeeding is strongly recommended by health professionals in the first months after birth.
A European consortium of researchers, led by the University of Southampton and the University of Reading, collaboratively conducted a dietary intervention study in which pregnant women were randomly assigned to eat their normal diet, or one high in salmon.
Researchers found that those mothers that had eaten salmon during the latter stages of their pregnancy increased the amount of long-chain omega-3 fatty acids in milk throughout the first month after birth, but also lowered levels of secretory immunoglobulin-A (sIgA) - an important antibody that helps protect the newborn against infection.
Findings from the study are published in the August 2012 issue of The Journal of Nutrition.
Philip Calder, Professor of Nutritional Immunology at the University of Southampton, led the study. He comments: “The results of the study are encouraging as they show for the first time that pregnant women who eat more oily fish pass on useful nutrients to their babies while breastfeeding. By following the current guidance of having two servings of oily fish a week during pregnancy, women can boost beneficial nutrients to help the early growth of their babies at a crucial stage of development. However, we need to conduct much more research to examine how the lower levels of antibodies in breast milk could affect the babies.”