Excerpted from Nutrition Action, May 24, 2015:
The Best Fish for Your Health and the Earth
Seven popular fish and finding a balance between the best fish for your health and for your dinner table
David Schardt
Which seafood choices are good for you…and the planet? There are plenty of reasons to be wary of seafood, such as possible PCBs, mercury, antibiotic residues, dioxins, sea lice in ocean pens, leveled mangrove forests, and depleted fish stocks.
But there also are plenty of reasons to eat it. People who consume more seafood have a lower risk of heart disease, stroke, and Alzheimer’s disease. Researchers aren’t sure if that’s because of DHA and EPA, the omega-3 fats in fish, or because seafood eaters do other things to protect their health. Still, seafood is low in saturated fat and rich in protein…and flavor.
How healthy is the most popular seafood? What’s it doing to the environment? Below you’ll find simplified versions of recommendations from the Monterey Bay Aquarium’s Seafood Watch program.
Is Tilapia the Best Fish For Your Health?
It’s the fourth most popular seafood in the United States. Some is raised here, but most of this mild-tasting fish now comes from farms in China, followed by Indonesia, Ecuador, and Honduras.
Good for people? Modest in omega-3s (about 150 mg in 4 oz. cooked). Very low in mercury. Fed a vegetarian diet (so it’s less likely to accumulate harmful chemicals).
Bad for people? A 2008 study found large amounts of arachidonic acid in farmed tilapia. Some charge that omega-6 fats like arachidonic acid cause inflammation. “But omega-6 fats don’t cause inflammation or promote heart disease,” says William Harris, of the University of South Dakota’s Sanford School of Medicine, who chaired the American Heart Association’s 2009 panel on omega-6s.
Tilapia from China and Taiwan are on an FDA watch list for illegal drug residues. In part, that’s why neither is a “best choice.”
Good for the Earth?
Best choice: Tilapia that’s tank-farmed in the United States or Canada or in carefully managed ponds in Ecuador.
Is Farmed Salmon the Best Fish For Your Health?
Americans are eating more Atlantic salmon, which is always farmed. Most of it comes from Chile, Canada, and Norway.
Good for people? Very high in omega-3s (about 2,400 mg in 4 oz. cooked). Very low in mercury.
Bad for people? In 2004, a chemical analysis of 459 samples of farmed salmon from five countries rattled seafood eaters. Most was so polluted with PCBs and dioxins that the researchers advised people to eat farmed salmon no more than once a month. The fish accumulate the industrial chemicals from the fishmeal they are fed.
Since then, the industry claims that it has been cleaning up its act by replacing some fishmeal with soy protein.
Has it worked? There’s no way to tell, since independent researchers haven’t done any recent testing.
In the 2004 analysis, farmed salmon from the United States, Canada, and Chile had lower levels of contaminants than farmed salmon from Northern Europe. For what it’s worth, a Norwegian study found that PCB and dioxin levels in its farmed salmon fell by half from 2004 to 2011. But no one has published recent good data on farmed salmon raised elsewhere.
Good for the Earth?
Best choice: U.S. farmed salmon—or any other farmed salmon—that are raised in “recirculating aquaculture systems” or “tank systems.” Good alternative: Verlasso farmed salmon from Chile.
Avoid: Most farmed salmon from Chile, British Columbia, Scotland, and Norway, which are raised in “net pens.” Why? Fish that escape from the pens can breed with wild salmon and can infect them with parasites.
Is Trout the Best Fish For Your Health?
Most farmed trout, unlike most farmed salmon, are raised in closed, man-made waterways that are essentially artificial streams. So trout farming doesn’t raise the same environmental concerns—about feed and feces polluting the ocean, residues of antibiotics getting into the environment, and fish escaping and breeding with wild fish.
Good for people? High in omega-3s (about 1,000 mg in 4 oz. cooked). Low in mercury.
Bad for people? Farmed salmon and farmed trout are both fed fishmeal and fish oil, which come from small oily fish— like menhaden—that absorb fat-soluble pollutants like PCBs and dioxins from their environment. There have been no recent analyses of farmed trout, but there’s reason to think that they’re cleaner than farmed salmon. “Trout are fed lesser amounts of fishmeal and especially fish oil because they’re smaller and live shorter lives,” says aquaculture expert Gary Fornshell, of the University of Idaho.
Good for the Earth?
Best choice: Rainbow trout farmed in the United States. Wild lake trout from Minnesota waters of Lake Superior.
Good alternative: Wild lake trout from Lake Huron, Lake Michigan, and Canadian and Michigan waters of Lake Superior.
Avoid: Wild lake trout from Wisconsin waters of Lake Superior.
Is Canned Tuna the Best Fish For Your Health?
Is canned tuna safe? Only in moderation.
Good for people? Modest to high in omega-3s (150 to 300 mg in 4 oz. of canned light and about 1,000 mg in 4 oz. of canned albacore).
Bad for people? Mercury can damage nerves, leading to memory loss, irritability, and balance problems. According to the FDA, it’s safe to get, on average, up to 7 micrograms (mcg) of mercury a week for every 22 pounds you weigh. That works out to around 50 mcg for a 150-pound person. Four ounces of canned albacore (white) tuna averages 40 mcg of mercury; that much canned light averages 13 mcg.
Because the developing nervous system is especially sensitive to mercury, we recommend that women who are nursing, pregnant, or could become pregnant, as well as children under 55 pounds, not eat albacore tuna. Those women should limit light tuna to 2 oz. a week (1 oz. for children). Other adults can safely eat up to 3 oz. of albacore or 12 oz. of light tuna a week.
Good for the Earth?
Best choice or Good alternative: Tuna caught by trolls, poles, or FAD-free purse seines. (FADs—fish aggregating devices— attract, catch, and waste a lot of other fish.) That typically means smaller brands like Wild Planet and Raincoast Trading.
Avoid: Tuna caught with gill nets, purse seines with FADs, or most longline methods. That includes Chicken of the Sea, Bumblebee, and (sorry, Charlie) Star-Kist.
Is Shrimp the Best Fish For Your Health?
Shrimp is the most popular seafood in the United States. Most of it is imported from shrimp farms in Asia and Ecuador.
Good for people? Modest in omega-3s (about 100 mg in 4 oz. cooked). Very low in mercury.
Bad for people? In 2014 tests carried out in Louisiana (where domestic shrimp competes with imports), 20 of 27 samples of farmed shrimp from Asia and Ecuador showed traces of fluoroquinolones, a class of antibiotics—Cipro is one—that is banned from food here. And 25 tested positive for malachite green, an anti-fungal compound not permitted in imported food. None of the 14 frozen U.S.-caught wild shrimp samples tested positive for illegal drug residues or malachite green.
In April 2015, Consumer Reports reported that of 205 raw farmed imported shrimp samples it purchased in U.S. supermarkets, 11 samples from Vietnam, Thailand, and Bangladesh tested positive for one or more antibiotics. (No antibiotics are approved by the U.S. Food and Drug Administration for use in shrimp farming. All are illegal in imported shrimp.)
Farmed shrimp from China, India, Malaysia, Mexico, Vietnam, Bangladesh, and Indonesia are on an FDA watch list for illegal drug residues.
Good for the Earth?
Best choice or Good alternative: U.S. farmed shrimp. Wild shrimp caught anywhere other than Mexico or Louisiana. The Monterey Bay Seafood Watch prrogram says, “Wild shrimp from Louisiana and Mexico are on the ‘Avoid’ list for poor management, illegal fishing or heavy bycatch loads that include sea turtles and many other species.”
Avoid: Most imported farmed shrimp.
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Is Wild Salmon the Best Fish For Your Health?
“Alaska’s icy, pure waters and the abundance of natural food give Alaska Salmon unparalleled flavor,” says the Alaska Seafood Marketing Institute. The downside: fresh wild salmon costs more than twice as much as farmed and is available only during the summer.
Good for people? High in omega-3s (about 1,500 mg in 4 oz. of cooked wild coho and 900 mg in cooked wild sockeye). Canned salmon, which is usually wild, has about 1,200 mg in a 4 oz. serving. Very low in mercury.
Bad for people? The 2004 analysis that found PCBs and dioxins in farmed salmon also found both in samples of wild Alaska salmon. But levels of contaminants were typically only about an eighth of those in the farmed.
Good for the Earth?
Best choice: Any wild salmon from Alaska.
Good alternative: Any wild salmon from California, Oregon, or Washington state. Wild coho from British Columbia. Any wild salmon from a Marine Stewardship Council Certified Fishery.
(from the Center for Science in the Public Interest)