Today in challenges to prevailing public-health wisdom: A new study in the American Journal of Clinical Nutrition shows that fish consumption in expectant mothers is associated with smarter, stronger babies. Researchers from Harvard University and Statens Serum Institut in Copenhagen, Denmark, interviewed a cohort of Danish mothers who gave birth to over 25,000 children between 1997 and 2002. The moms, who had already filled out detailed food questionnaires during pregnancy, were asked whether their kids had achieved specific physical and cognitive developmental milestones at 6 months and again at 18 months. "Compared with women who ate the least fish, women with the highest fish intake (about 60 grams -- 2 ounces -- per day on average) had children 25 percent more likely to have higher developmental scores at 6 months and almost 30 percent more likely to have higher scores at 18 months." Maybe fish really is brain food.
Or maybe not. Maybe mothers who are more likely to eat fish are also more likely to be genetically blessed, or to engage in parenting behaviors that might increase their kids' scores. (The same study showed that breast-feeding is also linked to higher developmental scores, for instance, though that effect was found to be independent of the one from maternal fish consumption.) Either way, though, the study did not show that eating fish during pregnancy led to issues associated with mercury poisoning, the fear behind the existing FDA recommendation that pregnant women eat no more than two servings of fish per week. Expectant moms are still advised to choose low-mercury fish, which most of the women in the Danish cohort did, but "in this case the nutrient benefits of prenatal fish appeared to outweigh toxicant harm."
Of course, this doesn't mean we should be sanguine about the effects of mercury pollution or the Bush administration's refusal to work toward reducing it in any meaningful way. But at least there's one less thing for pregnant women to beat themselves up about.