Can eating more fish during pregnancy help babies’ brains function better as they grow older? Yes, according to a new study from Spain. The researchers say that mothers who eat three substantial servings of fish – each week- during pregnancy may be giving their children an advantage as they mature.
Researchers followed nearly 2,000 mother-child pairs from the first trimester of pregnancy through the child’s fifth birthday and found improved brain function in the kids whose mothers ate the most fish while pregnant, compared to children of mothers who ate the least.
Even when women averaged 600 grams, or 21 ounces, of fish weekly during pregnancy, there was no sign that mercury or other pollutants associated with fish were having a negative effect that offset the apparent benefits.
“Seafood is known to be an important source of essential nutrients for brain development, but at the same time accumulates mercury from the environment, which is known to be neurotoxic,” lead author Jordi Julvez, of the Center for Research in Environmental Epidemiology in Barcelona, said in an email to Reuters Health.
This important health concern prompted the U.S. Food and Drug Administration (FDA) to come up with a guideline for pregnant women in 2014. It encourages women to eat more fish during pregnancy, but limit the intake to no more than 12 ounces per week.
For this study, researchers analyzed data from the Spanish Childhood and Environment Project, a large population study that recruited women in their first trimester of pregnancy, in four provinces of Spain, between 2004 and 2008.
Julvez and colleagues focused on records of the women’s consumption of large fatty fish such as swordfish and albacore tuna, smaller fatty fish such as mackerel, sardines, anchovies or salmon, and lean fish such as hake or sole, as well as shellfish and other seafood.
Women were tested for blood levels of vitamin D and iodine, and cord blood was tested after delivery to measure fetal exposure to mercury and PCB pollutants. At ages 14 months and five years, the children underwent tests of their cognitive abilities and Asperger Syndrome traits to assess their neuropsychological development.
On average, the women had consumed about 500 g, or three servings, of seafood per week while pregnant. But with every additional 10 g per week above that amount, children’s test scores improved, up to about 600 g. The link between higher maternal consumption and better brain development in children was especially apparent when kids were five.
The researchers also saw a consistent reduction in autism-spectrum traits with increased maternal fish consumption.
Mothers’ consumption of lean fish and large fatty fish appeared most strongly tied to children’s scores, and fish intake during the first trimester, compared to later in pregnancy, also had the strongest associations.
“I think that in general people should follow the current recommendations,” Julvez said. “Nevertheless this study pointed out that maybe some of them, particularly the American ones, should be less stringent.”
Julvez noted that there didn’t appear to be any additional benefit when women ate more than 21 ounces (about 595 g) of fish per week.
“I think it's really interesting, and it shed a lot more light on the benefits of eating fish during pregnancy,” said Dr. Ashley Roman, director of Maternal Fetal Medicine at NYU Langone Medical Center in New York.
“I think what's interesting about this study compared to some data previously is that they better quantify the relationship between how much fish is consumed in a diet and then the benefits for the fetus and ultimately the child,” said Roman, who was not involved in the study.
Roman also noted that pregnant women should avoid certain fish such as tilefish, shark, swordfish and giant mackerel. These are larger fish with longer life spans that may accumulate more mercury in their tissue.
While fish may be a great source of protein and benefit brain development in utero, most experts agree that women should consult their obstetrician about what fish are safer to eat and how much they should eat during pregnancy.
The study was published online in the January edition of the American Journal of Epidemiology
Source: Shereen Lehman, http://www.reuters.com/article/us-health-pregnancy-fish-idUSKCN0UW1S4