We’ve heard the conflicting news.

Don’t eat fish. It’s high in toxic mercury.

Eat fish. It’s good for your brain.

Sometimes with that conflicting advice, it’s hard to know how to make a decision.

Mercury in fish: how much is safe?

Recently, Edward Groth III, a PhD in biological sciences, published a paper in Environmental Research proposing a model that ranks fish eaten as seafood by relative benefits and risks that are also consistent with epidemiological observations.

You can read the paper here.

What’s interesting in the paper are several things.

His consumption guide is clear with a color coded key that shows which fish are simply too risky to eat. These include the usual suspects of shark, swordfish, and king mackerel.

Fish Consumption Chart - GrothAnother interesting way that he analyzes the information in order to assess a broader public health risk is to calculate what percentage mercury each type of fish contributes to the US seafood supply.

Some of the interesting results from this are that:

  • The five species of the fish highest in mercury (swordfish, shark, orange roughy, Gulf tilefish, and King mackerel) account for more than 10% of the mercury contribution in the US diet.
  • More than 27% of the mercury in the seafood diet comes from canned albacore tuna and fresh/frozen tuna even though he categorizes them in the orange category rather than red category because they are lower in mercury concentrations.
  • 75% of the mercury coming from fish in the US diet come from only 10 species (out of 46 listed) largely because of how much is consumed.

Groth’s paper is important since the issue of mercury in fish is complex and guidelines developed to protect public health also need to reflect this complexity.

To evaluate whether the fish you are buying is high in mercury, please visit our easy to use mercury-in-seafood calculator at http://www.gotmercury.org