by Anne Eglash MD, IBCLC, FABM
Here’s something fishy… It is safe to eat fish during pregnancy. Whaaat?
Surely you’ve heard that fish is the miracle food? Fish is high in protein, and its heart-healthy fats, along with other nutrients, promote healthy brain development in fetuses and young children. But should pregnant and/or nursing women, and young children eat fish? Many families avoid fish consumption during pregnancy, lactation, and in meals for young children because of the risk of mercury exposure.
There is now strong evidence that despite small nontoxic amounts of mercury exposure, moderate fish consumption during pregnancy can raise a child’s early verbal development and IQ.
In 2014, The United States Food and Drug Administration (FDA) released a report entitled A Quantitative Assessment of the Net Effects on Fetal Neurodevelopment by Eating Commercial Fish (As Measured by IQ and also by Early Age Verbal Development in Children)’. Read here.
The FDA reports that if pregnant women eat between 8 oz and 12 oz of fish each week (most fish species eaten in the United States) their child may gain 3.3 IQ points by age 9, without significant mercury exposure. Eating 12 oz of fish each week will give the maximum benefit for early verbal development and IQ. This means that eating more than 12 oz a week during pregnancy does not necessarily raise the IQ beyond the approximate 3.3 points, and may lead to more mercury exposure.
In fact, they report that eating less than 3 oz of fish a week during pregnancy is harmful to the fetus’s brain due to lack of exposure to the nutritional benefits of fish, even though the mother is avoiding mercury exposure.
The authors of The 2014 FDA assessment of commercial fish: practical considerations for improved dietary guidance used the FDA’s report to outline the most cost-effective ways to follow the FDA’s fish consumption guidelines.
Based on their calculations, canned light tuna is the least expensive and safest way to consume the recommended 8-12 oz of fish each week.
How many meals per week of canned light tuna does a pregnant woman need to eat in order to expose her fetus to excessive mercury?
- 18 meal/week
- 35 meals/week
- 50 meals/week
- 90 meals/week
See the Answer
Jennifer McGuire, Jason Kaplan, John Lapolla, and Rima Kleiner, Nutrition Journal 2016 15:66
The U.S. Food and Drug Administration (FDA) recently released its report: A Quantitative Assessment of the Net Effects on Fetal Neurodevelopment from Eating Commercial Fish (As Measured by IQ and also by Early Age Verbal Development in Children). By evaluating the benefits and potential concerns of eating fish during pregnancy and breastfeeding, the analysis suggests that pregnant women consuming two seafood meals (8–12 oz) per week could provide their child with an additional 3.3 IQ points by age 9. Recent insights from behavioral economics research indicate that other factors, such as concerns about price and methylmercury (MeHg) exposure, appear to reduce fish consumption in many individuals.
To assess the net effects of eating commercial fish during pregnancy, we compared the consumption of select fish species necessary to achieve IQ benefits with the amount necessary to have adverse developmental effects due to MeHg exposure. For the species or market types evaluated, the number of servings necessary to reach MeHg exposure to observe an adverse effect was at least twice that the amount estimated to achieve peak developmental benefit. We then reported average costs of fresh and canned or pouched fish, and calculated the cost per week for pregnant women to achieve maximum IQ benefits for their gestating child. Canned light tuna was the least expensive option at $1.83 per week to achieve maximum IQ benefit.
Due to their relatively low cost, canned and pouched fish products eaten with enough regularity are likely to provide peak cognitive benefits. Because of its popularity, canned and pouched tuna could provide some of the largest cognitive benefits from fish consumption in the U.S. Future FDA consumer advice and related educational initiatives could benefit from a broader perspective that highlights the importance of affordable and accessible fish choices. These observations underscore the importance of clear public health messaging that address both healthbenefits and such real-world considerations as cost and convenience. Read the article.
Milk Mob Comment:
Well this is a different kettle of fish. Finding healthy fish to eat during pregnancy is nothing like shooting fish in a barrel. I suggest that we share this information with the families we work with. Who wouldn’t fish for ways to improve their unborn child’s IQ? The FDA report has a table on page 104 that lists the amount of mercury in different fish species, the number of ounces to be eaten by a pregnant mother each week to reach the maximum benefit for her child’s IQ, and the number of oz per week causing excessive mercury exposure. Although shrimp, scallops and tilapia have the lowest mercury levels, thankfully there are other good fish in the sea. Advising no fish during pregnancy is now a whale of a tale!