By Mary Parsons, MS, RD
Mercury enters the ocean ecosystem from both industrial pollution and naturally-occurring ore deposits, and it can accumulate in fish to levels that can be potentially harmful to humans. Mercury contamination in seafood is a risk, but with a little knowledge and attention, the risk is manageable. The high-quality protein and healthy fats in seafood offer lots of health benefits, so don’t let fear of mercury keep you from ordering healthy fish options.
The Environmental Protection Agency (EPA) recommends that if you stick with low-mercury seafood options (more on that below!), adults can safely eat about 12 ounces – the amount that you would eat in about two standard restaurant portions – each week. This lets you enjoy the health benefits of seafood with minimal risk of harm from elevated mercury levels. Be aware that while adults are able to tolerate higher mercury levels without symptoms, the developing brain and nervous system are more sensitive to the effects of mercury; therefore, children, pregnant or breastfeeding mothers, and women who may become pregnant are subject to more restrictions; refer to the American Pregnancy Association for more details.
Some of the most common low-mercury seafoods recommended by the EPA are shrimp, canned light tuna, salmon, pollock, and catfish. Fish with the highest levels of mercury – including shark, swordfish, king mackerel and tilefish – should be avoided or severely limited. While mercury levels can vary based on location, species, size and age of the fish, for general guidelines we recommend consulting the Consumer Guide to Mercury in Fish from the Natural Resources Defense Council.
When eating out at seafood restaurants, opt for dietitian picks on Healthy Dining Finder to get your recommended servings of seafood without taking in too much mercury!