Love Salmon? There's Scary News

Farm-raised salmon, which is the kind commonly sold in grocery stores, contain significantly more cancer-causing chemicals than salmon that are caught in the wild, warn researchers from the University at Albany in New York, who tested 700 salmon worldwide.

Although the U.S. Food and Drug Administration insists the levels of 13 pollutants found in salmon are too low for serious concern, this new international study shows that farm-raised salmon have enough dioxins and other potentially cancer-causing pollutants that the researchers are cautioning consumers to eat salmon no more than once a month. The Associated Press reports that the average dioxin level in farmed-raised salmon was as 11 times higher than that in wild salmon--1.88 parts per billion compared with 0.17 ppb. For PCBs, the average was 36.6 ppb in farm-raised salmon and 4.75 in wild salmon.

The researchers actually go so far as to warn that eating farm-raised salmon more than once a month--depending on its country of origin--could slightly increase your risk of getting cancer later in life. In this study, salmon farmed in Northern Europe had the most contaminants, followed by North America and Chile. More than half the world's supply of salmon is farmed.

Answers to the big questions:
Where is most of the salmon farmed that we eat in the United States?
Chile. And that's good news. The pollutant level in Chilean salmon was not too much higher than that found in some wild-caught salmon, notes AP.

Where are these contaminants coming from? The feed, which is made of fish oil and meal from just a few species of ocean fish. This concentrates the ocean contaminants to which the farm-raised salmon are exposed. Wild salmon eat a greater variety. When any fish or animal absorbs these pollutants, they are stored as fat and not secreted. So if the fish has the contaminates in its fat and the fish is eaten by a human, the contaminants that were in the fish are then stored in the human's fat. However, the salmon farming industry points out that all the pollutant levels are well within the FDA's legal limits, notes AP.

Will the farmers change the feed? Many salmon farmers in the United States, Canada, and Chile doing just that. But it's a slow process. Instead of using fish oil in the salmon feed, they are switching to soybean oil and canola oil, which don't have the pollutants.

What level of pollutants is considered safe? The government does not have one set level of dioxins and PCBs that is considered safe in foods.

What can you do as a consumer? Until the farmers change the feed they use, your best bet is to buy wild salmon. Wild salmon sells for about $15 a pound, compared with $4 to $5 a pound charged for farm-raised salmon.

Will cooking help remove pollutants? If you do eat farm-raised salmon, the FDA recommends cutting off the skin and grilling it. This will remove a significant amount of PCBs, dioxins, and other pollutants stored in the fish fat.

Is the government concerned? No. The FDA says the levels of pollutants are too low for concern and recommend Americans not make any changes in their diets. Even a nutrition and chronic disease specialist at the Harvard School of Public Health is worried the study will frighten people. "To alarm people away from fish because of some potential, at this point undocumented, risk of long-term cancer--that does worry me," Eric Rimm told AP.

"We are certainly not telling people not to eat fish," lead study author David Carpenter told AP. "We're telling them to eat less farmed salmon."

The research findings were published in the journal Science.