Your diet and your baby’s help her development
Both higher fish consumption and longer breastfeeding are linked to better physical and cognitive development in infants, according to a new European study. Maternal fish consumption and longer breastfeeding were independently beneficial.
Researchers looked at 25,446 children, interviewing their moms about child development markers at 6 and 18 months postpartum and asking about their breastfeeding at 6 months postpartum. Prenatal diet, including amounts and types of fish consumed weekly, was assessed by a detailed food frequency questionnaire administered when they were six months pregnant.
During the interviews moms were asked about specific physical and cognitive developmental milestones such as whether child could hold up his/her head, sit with a straight back, sit unsupported, respond to sound or voices, imitate sounds, or crawl by the age of 6 months. At 18 months, they were asked about more advanced milestones such as whether the child could climb stairs, remove his/her socks, drink from a cup, write or draw, use word-like sounds and put words together, and whether they could walk unassisted.
The children whose moms ate the most fish during pregnancy were more likely to have better motor and cognitive skills. For example, among moms who ate the least fish, 5.7% of their children had the lowest developmental scores at 18 months, compared with only 3.7% of children whose moms had the highest fish intake. Compared with women who ate the least fish, women with the highest fish intake (about 2 ounces per day on average) had children 25% more likely to have higher developmental scores at 6 months and almost 30% more likely to have higher scores at 18 months.
Longer duration of breastfeeding was also associated with better infant development, especially at 18 months. Like fish, breast milk contains omega-3 fatty acids. The benefit of fish consumption was similar among infants breastfed for shorter or longer durations.
Women in the US have been advised to limit their fish intake to two servings a week because some fish contains high traces of mercury, which has demonstrated toxic effects. Information regarding mercury levels among the moms in the study wasn’t collated but most of them said they consumed cod, plaice, salmon, herring, and mackerel; fish types that tend to have low mercury content. In this study, consumption of three or more weekly servings of fish was associated with higher development scores, so in this case the nutrient benefits of prenatal fish appeared to outweigh toxicant harm. Previous studies also have linked higher prenatal fish consumption with an overall benefit for child cognitive development.
In 2004, the Environmental Protection Agency (EPA) and the Food and Drug Administration (FDA) issued a joint advisory to pregnant and nursing women warning that excessive consumption of high mercury fish can have dangerous neurological consequences to infants and young children. Methylmercury, the toxic metal found in all fish, is present at the highest levels among swordfish, shark, bluefin mackerel, tilefish and tuna. However, many women are confused about how much fish they should eat in pregnancy and conflicting reports about safe levels of mercury in fish mean that many pregnant women eliminate fish from their diet altogether. Information on mercury levels in commonly consumed fish is available at the FDA website.