During this Lenten season, those of us who give up meat on Fridays will be eating fish. We know including fish in our diet can offer nutritional benefits–a 6-ounce serving offers a hefty dose of B vitamins, some minerals, and those beneficial omega-3 fats.
But we’ve also heard other things about fish. Every year an advisory is issued for pregnant women and young children that calls for a limit on the amount and types of fish they eat. That’s because all fish, all fish, is contaminated with methylmercury, a neurotoxic element that is particularly dangerous for a fetus or young child.
Because the amounts of methylmercury in fish vary greatly, to eat fish safely, you need to know what fish are more likely to contain more methylmercury.
But as a recent NPR article points out, lists can be confusing. For starters, you have to know what they are filtering for. Very often it’s for sustainability, not methylmercury . Only two out the most commonly referred to guides take mercury content into consideration.
Monterey Bay Aquarium Seafood Watch Regional Consumer Guide or App
- Recommendations help you choose seafood that’s fished or farmed in ways that have less impact on the environment.
Environmental Defense Fund Seafood Selector
- Scientists analyze many aspects of wild fisheries and fish farming operations for more than 200 types of seafood frequently sold in the US market.
- They collaborate with the Monterey Bay Aquarium Seafood Watch Program.
- They rank mercury content in fish with a vague category: unknown, moderate, or elevated.
Environmental Working Group’s Consumer Guide to Seafood
- Since government and independent scientists have not reached a consensus on a safe level of mercury exposure, it makes recommendations that are aimed to steer people to toward seafood with the best safety profiles.
- Until the EPA completes its multi-year process to revise its assessment of mercury toxicity, this guide recommends that pregnant women and children consume no more than 75% of the EPA’s safety level. This builds in an extra margin of safety.
Similar to our ubiquitous and unknown levels of exposure to fluoride, mere avoidance of mercury is not only complicated, but political.
Since 1994, when the first published advisory about methylmercury in fish was issued, the FDA and the EPA have come under scrutiny. This year’s advisory is no different. A public health watchdog organization,  the Environmental Working Group, fired back on the “shocking” EPA-FDA advice about eating fish and shellfish. As an eater, you have to wonder, who do you trust and what do you do?
Concern is a good indication that we need more information, for example:
- How does the mercury from your teeth get into fish?
- How does mercury get into fish?
- Methylmercury advice BEFORE pregnancy?
- What does methylmercury exposure do to children’s health?
- How do you know if you’re poisoning yourself with fish?
- What does mercury poisoning look like?
The answers to these questions don’t mean you can’t eat fish. But they do suggest it may be best to check with a guide or a print off list. Things can, and do, change.
Image by Art Siegel