The 6 Best Low Mercury Fish, According to Dietitians

If you've ever been warned to watch how much fish you eat, there might be a good reason.

'Some of this concern is valid, given that most of the methylmercury in our bodies comes from eating seafood, and that mercury levels in seafood appear to be on the rise,' says Kim Yawitz, R.D. 'But for most people, the benefits of moderate seafood consumption exceed the risks—especially if you choose varieties lower in mercury.'

Albacore (or white) tuna might be one of the main culprits of the mercury fear-mongering. It has been shown to contain more mercury than other kinds of tuna. Because of this, consumers are advised to choose the lower mercury option when able and consume no more than six ounces of canned albacore tuna per week, says Lisa Ciarametaro, R.D.N.

Is it a concern in other kinds of fish, though? Here’s what you should know.

What is mercury?

'Mercury is a naturally occurring element that’s present in the earth’s crust. It’s released into the atmosphere when volcanoes erupt or as rock erodes, but most of the mercury in the atmosphere comes from human industrial practices – like smelting and burning coal,” Yawitz says. “These mercury particles eventually make their way into bodies of water, where they’re converted by bacteria into a substance called methylmercury.'

Is mercury unhealthy?

Mercury is a neurotoxin, so if you get too much of it, it can harm the nervous system, says Yawitz. But the reputation mercury gets as bad-for-you is a bit deceptive, as you really need to eat a lot of it to experience adverse health effects.

That being said, it’s best for certain populations, including young children and women who are pregnant or plan to become pregnant, to limit their consumption of higher-mercury fish and shellfish. For most men, though, mercury consumption isn’t an issue.

'Most healthy adults would need to consume a lot of higher-mercury fish over long periods of time to develop any symptoms of mercury poisoning,' she says.

As for how much mercury is dangerous, the exact number is up for debate. Per Ciarametaro, tissue concentration of 100 ng/mL of methylmercury or greater is commonly considered "high". Your doc can test your mercury levels via blood or urine tests.

If you're looking for low mercury fish, here's a rule for the wise: 'Generally speaking, it is best to look for fish that are considered "non-pelagic’ or ‘ground fish,"' says Ciarametaro. Meaning, fish that typically do not spend their life span in deep water or in the open ocean, as they tend to have less bioaccumulation of methylmercury.

Here are six low-mercury fish dietitians recommend.