There seems to be an ever-increasing list of considerations to factor in when shopping for ourselves and our families. Is the food we’re selecting delicious? Is it nutritious? Will it be easy to prepare? Was it responsibly sourced? All of these questions apply to seafood, both canned and fresh. However, relatively recently another factor has been entered into the consideration set and that’s mercury in fish. Often positioned as something to be quite fearful of, without explanation and context the subject of mercury and how to evaluate it can be confusing. Here, we’ve tried to provide a quick summary of what mercury is, why it’s in seafood, how to evaluate that fact and provide reassurance that the pole & line caught tuna that Wild Planet has been proudly producing for nearly 20 years is something you can feel confident in feeding yourself and those you love the most.
1) Mercury is naturally present in seafood.
Mercury is naturally occurring and it comes in three forms: elemental, inorganic and organic. Elemental mercury occurs as a silver-colored liquid. Inorganic mercury is formed when mercury combines with other elements like sulfer and oxygen. These compounds are often used in industrial processes and in the production of chemicals. Organic mercury, also known as methylmercury (MeHg) is formed when mercury combines with carbon. MeHg is found in air, water & soil and over time it releases itself into the environment, including the oceans. Methylmercury is found in marine ecosystems and as a result, trace levels of mercury can be found in all sea life.
2) Research consistently supports the idea that adults should eat seafood weekly.
Despite the fact that mercury is naturally present in seafood, the thought of consuming foods containing some mercury might make people nervous. The great news is that the levels in seafood (specifically mercury in tuna, mercury in salmon and mercury in sardines) are generally so low that there’s nothing to be overly apprehensive about. However, it is important to note that there are some species of tuna that are high in mercury and they should be consumed in moderation. The Food and Drug Administration (FDA) and the Environmental Protection Agency (EPA) provide helpful guidance on how to navigate seafood choices safely so the question isn’t whether or not one should eat fish. Rather, the question is how much fish (and which fish) should each of us consume?
The Dietary Guidelines for Americans recommends that adults consume at least 8oz of seafood per week. Doing so has the potential to provide a wide variety of health benefits including improved brain health and a reduced risk of heart disease. This is due to a robust and efficient delivery of essential nutrients such as protein, vitamin D, calcium and essential omega-3 fatty acids like EPA and DHA. Seafood is also low in saturated fat.
3) The benefits of eating fish outweigh potential contaminants even for women who are pregnant or breastfeeding.
The American College of Obstetrics and Gynecology (ACOG) in conjunction with the guidelines established by the FDA and EPA believe it is safe for pregnant or breastfeeding women to eat 8-12 ounces of seafood each week. However, research shows that half of all pregnant women are only eating two ounces or less weekly and therefore, are not capturing the nutritional benefits needed by them and their developing babies. These benefits include better fetus brain and eye development, reduced risk of mental illness, and a healthy heart.
4) The EPA and FDA have provided guidance regarding mercury in seafood and which species are the best to eat.
The “Best Choices” for pregnant or breastfeeding women include two-three servings/week of: The “Good Choices” for pregnant or breastfeeding women include one serving/week of:5) Selenium can help to mitigate certain effects of mercury
Selenium is a trace mineral found in grains, poultry, red meat and fish; it is also a powerful antioxidant that may reduce cancer risk and it is essential for thyroid function and the immune system. Interestingly, mercury has a strong binding affinity for selenium and when we consume seafood, the two are bonded together and create a substance that is not absorbable in our bodies. This means the mercury levels in fish we consume will be attached to the selenium and likely removed from our bodies before they can ever be deposited and cause toxicity.
6) Canned tuna generally has lower levels of mercury than fresh or frozen tuna fillets.
The natural order of the food chain is such that mercury concentration increases as small fish get eaten by medium fish who in turn get consumed by large fish who ultimately, may be consumed by humans. The larger the fish (which often times means the older the fish), the higher the mercury levels. Fortunately, the tuna used in canned light tuna typically comes from species that are smaller in size and these species are usually younger when caught. This is particularly true of pole & line caught Skipjack tuna.
7) Wild Planet only sources pole & line and troll caught tuna, which are the younger and smaller, migratory tuna. These fish are naturally lower in mercury.
Caught near the surface of the water, the tuna Wild Planet sources are younger (typically 3-5 years of age) and have accumulated lower levels of mercury as compared to older and larger tuna (6-12 years of age), which live at much lower depths of the ocean.
