Eating fish is wise, but it’s good to know where your seafood comes from

Indeed, Love co-authored a 2011 study that found “a lot of veterinary drug residues in commonly eaten seafood, particularly shrimp and particularly from Southeast Asia.” The imports with the highest rate of violations? Shrimp or prawns, eel, crabs, catfish or pangasius, tilapia and salmon. The countries most likely to be cited were Vietnam, China, Thailand, Indonesia, Taiwan, India and Malaysia.

It remains to be seen what the health implications of this are, since there have been no good long-term studies on the topic. “It’s difficult to say whether there are health effects from the low-level residues of drugs of all sorts in seafood,” Love says. “We might have long-term or chronic health issues associated with that, but it’s not obvious, and with very low-level residue, it’s really hard to study.”

Health questions aside, one consideration for seafood lovers is that the nutritional profile of farmed fish isn’t always as beneficial as that of wild-caught species, according to Andrew Weil, a physician who is director of the Arizona Center for Integrative Medicine. “When fish are penned, they don’t get normal exercise, so they don’t build up as much muscle protein as normal and may have lower protein levels, and the healthy-fat content of oily farmed fish may not be as good as that of wild fish — it depends on what it’s being fed,” he says.

So what’s a health-conscious consumer to do?

“It’s important to be aware of where your seafood is coming from,” says Love, who adds that this information is required by law to be available to consumers and should be prominently displayed in grocery-store seafood cases. (To complicate matters, Love notes that there are “a lot of gray areas” in labeling; for example, he says, “about half of salmon caught in Alaska that are [marked and sold as] wild were raised in a hatchery and then released into the wild.”)

“Personally,” says Moore, of Food and Water Watch, “I try to eat as little farmed or imported seafood as possible. I eat local and wild as much as I can. But the U.S. actually has pretty good fisheries management and oversight, so if you’re eating domestically farmed fish, you’re pretty safe.”

For those in search of more specific advice, the Monterey Bay Aquarium Seafood Watch offers a “super green” list of fish that are good for human health — meaning low in contaminants and high in omega-3s — as well as abundant, well managed and fished or farmed in environmentally friendly ways.

Its top choices include troll- or pole-caught Albacore tuna from the United States or British Columbia; freshwater coho salmon farmed in American tank systems; farmed oysters; wild-caught Pacific sardines; farmed rainbow trout; and wild-caught salmon from Alaska.

Meanwhile, the seafood selector of the advocacy group Environmental Defense Fund advises avoiding several species, including farmed salmon, due to contaminants and green concerns.

All of that said, most experts still maintain that eating any fish — farmed, imported or otherwise — is better than avoiding seafood entirely.

“I would much rather see people eat farmed salmon than no salmon at all,” says Weil, choosing the species that is most often cited as suspect. “The benefits of eating farmed fish — including brain health, emotional health, inflammation control, heart health and the reduction of cancer — moderately outweigh any risks.”