Mercury in Fish: What You Need to Know
If you eat a lot of fish should you worry about mercury? High levels of mercury can cause tingling or numbness in fingers and toes and vision problems. It affects infant brain development. Even consistent, low-level mercury exposure can leave you fatigued or make concentrating difficult.
Tricky thing is, the major source of mercury in our diet is seafood, a really healthy choice in many other ways. It’s packed with protein, selenium, vitamins D and B12. So don’t bypass the seafood counter: USDA’s Dietary Guidelines say to eat at least 8 ounces of seafood a week—choosing lower-mercury fish (salmon, shrimp, canned light tuna, tilapia, cod) and some omega-3-rich fish. Follow these guidelines and you should be fine.
So where’s the line of “too much”? If you cook up a high-mercury fish even just once a month, some say you might get too much mercury. High-mercury fish include tilefish, shark, swordfish, albacore tuna and king mackerel. And a 2016 Environmental Working Group report found that eating tuna steaks, sushi tuna, sea bass, halibut and marlin could also lead to too much. Still, there’s no clear cutoff. “The kind of fish you eat matters just as much as the frequency,” says Roxanne Karimi, Ph.D., research scientist at Stony Brook University. Your best bet? Use EWG’s Seafood Calculator to get a customized seafood recommendation for your age, weight and gender.
Bottom line: Don’t spurn seafood. Research shows its benefits far outweigh any risk. Mix it up and be judicious with higher mercury varieties. For good measure, maybe add a squeeze of lemon to your fish—its vitamin C might help clear the toxin from your body. If you’re really worried, get a blood test.