Can we still eat fish? Years of polluting the ocean have taken their toll, and the once glorified health benefits of consuming fish have come under scrutiny due to contamination of seafood with mercury.
Fish is an excellent source of high quality, lean protein. It’s low in saturated fats and high in omega-3 fatty acids; these lower blood pressure, the risk of abnormal blood clots, and the risk of sudden death from heart disease.
Mercury makes its way into the ocean via power plant emissions, chemical manufacturers, cement plants, and landfills. Once in the water, mercury is converted by bacteria into methylmercury and becomes integrated into the food chain. Larger fish eat smaller fish, and the mercury accumulates in ever-increasing amounts. The largest concentrations are found in the big predators, such as tuna, swordfish, shark, and mackerel.
This week, Consumer Reports advised that pregnant women should no longer eat tuna. The concern in pregnancy, in particular, is that mercury can cross the placenta, where it acts as a potent neurotoxin in the vulnerable fetal brain. While I love Consumer Reports and rely on their advice when I purchase a car, most physicians don’t consider it to be an authoritative source of medical information.
The quintessential source of information comes from the FDA and the EPA, which jointly issued new guidelines in June 2014 for the consumption of fish in pregnancy. Even if you’re not pregnant, you probably need every one of your brain cells and would benefit from lessening neurotoxins in your life. So I recommend that everyone follow these guidelines.
(On a related note, when you get the flu vaccine injection at your local pharmacy, it comes from a multi-dose vial packaged with the preservative thimerosal, a mercury derivative. This version is contraindicated in pregnancy, and similarly, I think we all could benefit from the single-dose packaging, which doesn’t contain thimerosal. This is the only version that I offer in my office.)
The most important parts of the guidelines are as follows:
1. Eat 8-12 ounces of a variety of fish a week.
2. Choose fish lower in mercury. These include salmon, shrimp, pollock, tuna (light canned), tilapia, catfish, and cod.
3. Avoid 4 types of fish: tilefish from the Gulf of Mexico, shark, swordfish, and king mackerel. These 4 types of fish are highest in mercury. Don’t eat these again in your lifetime.
4. Limit white (albacore) tuna to 6 ounces a week.
The guidelines list each common type of fish along with its average mercury content. Think about copying this into a folder on your phone to consult when you go shopping or are ordering at a restaurant. Find the guidelines and a lot more information here: