Environmental Working Group (EWG) has produced a new study called “U.S. Fish Advice May Expose Babies to too Much Mercury.” In it, they say that “adhering to the federal government’s recommendations on seafood and mercury may be risky, potentially leading women to eat too much of the wrong kind of fish.” The guidelines were issued as a draft recommendation in 2014 that recommended that women who are pregnant or breastfeeding eat more fish that is lower in mercury.
Their tests found that mothers who eat species of fish in the amounts recommended by the EPA and FDA may risk exposing their fetuses to harmful levels of mercury. And those species do not have enough omega-3 fatty acids that are recommended in the diet. Mercury has toxic effects on the nervous, digestive and immune systems, and on lungs, kidneys, skin and eyes. It is especially dangerous to fetuses developing in the womb.
Dr. Philippe Grandjean, an adjunct professor at the Harvard School of Public Health said in a statement, “when you eat seafood during pregnancy, you get the benefits from omega-3s but from mercury you have the risk of toxicity. If you get a little bit of mercury it can be offset by the omega-3s. But that means you don’t get the full benefit of the omega-3s and other nutrients in seafood.”
Environmental Working Group recruited 254 women of childbearing age from 40 states. They stated that they ate as much or slightly more fish than recommended by the FDA. Samples of their hair were tested. Almost three in ten of the women had more mercury in their bodies than the EPA says is safe.
Those women who ate seafood often had about 11 times as much mercury as a comparison group who only eat seafood rarely. That establishes that the mercury in the women’s bodies comes from fish, if the study was controlled for other factors.
FDA recommendations are that women eat no more than six ounces a week of canned albacore tuna. The species that should not be eaten because of higher mercury content include shark, swordfish, tilefish, and king mackerel.
But, alarmingly, the analysis discovered that only a small amount of mercury comes from species that the government says to avoid. Most of the toxin came from species the FDA doesn’t warn about: tuna steaks and tuna sushi.
EWG would like the FDA and EPA to update their recommendations to include the full list of low mercury and high omega-3 fish, such as salmon, that should be included in diets. And the government’s advice should be updated to inform women about the dangers of mercury and name other species they should avoid for up to 12 months before conception. Those include seabass, halibut, and marlin.
EWG offers a Good Seafood Guide you can download, which provides guidelines for those who want to limit mercury consumption and increase intake of omega-3 fatty acids. They also have a Seafood Calculator that estimates portion size and the frequency of consumption based on a child’s or adults weight. You can download a copy of their project at their site, or watch a video made about the findings and recommendations.