One fish, too much fish, how much fish?

Originally Published: March 27, 2014
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Dear Alice,

How often should I eat fish?

Dear Reader,

This is a simple question for which there is no simple answer! How often you should eat fish depends on a variety of factors, including your specific health concerns, the type of fish you like to eat, how much you weigh, whether you’re pregnant or breastfeeding, and how much fish you eat per sitting. In addition to being quite tasty, fish can have many nutritional benefits, including being low in cholesterol, a good source of protein, and chock full of Omega-3 fatty acids. The American Heart Association even recommends eating a variety of fish, preferably oily fish (e.g., salmon, tuna, herring, etc.), at least twice a week.

Most people can eat fish without being concerned, but pregnant and breastfeeding women and young children should be more careful. Nearly all fish and shellfish contain traces of methylmercury, a type of mercury that can be harmful for pregnant women and young children. Mercury is present in both freshwater and oceans throughout the world as a result of industrial pollution. Generally speaking, older fish, larger fish, and fish that eat other fish will have accumulated the most mercury, thus there is lots of variation in mercury levels. There are three primary factors to monitor if you are trying to lower your consumption of mercury. These include the type of fish, the frequency you eat it, and the amount you eat per meal.

Some good general guidelines for fish consumption:

  • Eat fish that are lower in mercury. These include anchovies, clams, oysters, herring, tilapia, whiting, shrimp, sardines, salmon (in some cases), and a few others.
  • Eat less fish that are higher in mercury. These include tuna (especially steaks and sushi), Chilean Sea Bass, sharks, swordfish, eel, halibut, and orange roughy.
  • Eat a variety of fish. As an alternative to completely cutting high mercury fish out of your diet, simply eating a variety will make it more likely that some of the fish you consume is of the lower mercury variety.
  • Eat smaller (or fewer) servings of fish. Eating fish less frequently and eating smaller amounts will help keep mercury levels in check.

To get a more precise calculation of how often you should eat fish, check out the National Resources Defense Council's Mercury Contamination in Fish - Consumer Guide to Mercury in Fish. Other helpful resources include the New York City Department of Health – Mercury and Fish, the Environmental Protection Agency, and New Yorkers can check out New York State Fish Advisories.

If you are still concerned about the amount of fish you should include in your diet and if there are any restrictions based upon your individual health needs, you should make an appointment with your primary care provider or a registered dietitian to discuss. Columbia students on the Morningside campus can make an appointment at Medical Services using Open Communicator or by calling 212-854-2284. Columbia students at the Medical Center can make an appointment with Student Health or by calling 212-305-3400. 

Bon appétit!

Alice