Farmed Salmon Carry Harmful Toxins
by Sherry Morse
Farmed salmon carry about ten times more cancer-causing chemicals than wild salmon, according to a new study.
The study, conducted at Indiana University, Cornell University and the University of Albany, examined the levels of 14 toxins, all likely to cause cancer in humans.
The two metric tons of salmon used in the study were purchased in 16 cities in North America and Europe.
The toxins examined included industrial pollutants known as polychlorinated biphenyls (PCBs) which have been found to cause cancer in humans and have been linked to developmental defects, including decreased intelligence, in children.
PCBs were highest in fish from Scotland and from the Faroe Islands near Scotland.
The study's authors believe that PCBs from the manufacture of paints and flame retardants and from waste incineration find their way into small fish that are caught and processed into food for the farmed salmon.
Farm-raised Atlantic salmon - similar to the fish found at Scottish farms - were found to have significantly higher levels of 13 toxins compared with wild Pacific salmon.
According to David Carpenter of the University at Albany, although salmon is rich in omega-3 fatty acids which protect against heart disease, people who have a low risk of heart problems should actually avoid eating salmon, due to the high levels of PCBs in the fish.
Robert Lawrence, a public health expert from Johns Hopkins University in Baltimore, agreed.
"It might be good for middle-aged men, but not for childbearing women and children," he said.
Lawrence added that salmon on US farms are fed recycled fat from slaughtered animals, including cows; and because they are consuming material from higher in the food chain, which might already have high levels of PCBs, the salmon have a greater chance of having high levels of PCBs themselves.
Carpenter believes that if farmers fed the salmon a vegetarian diet - substituting soybeans or flaxseed for fish protein - the levels of PCBs in the fish would be reduced.
Flaxseed oil is also rich in Omega-3 acids and could be used by itself, as a substitute for salmon, by those seeking to increase their heart health.
Based on the United States Environmental Protection Agency's recommended maximum intake of organochlorides - of which PCBs are a part - most consumers would have to limit their salmon consumption to just two ounces per month of Scottish or Faroe Island salmon, or eight ounces per month of uncooked farmed salmon from other European or American markets.
In comparison, eight ounce servings of wild salmon could be consumed as many as eight times in a month.
The salmon-farming industry is a significant source of jobs and revenue in Scotland. So far, the Scottish industry has reacted to the PCB scare with outright denial and defiance.
John Webster, a spokesman for Scottish Quality Salmon, representing the Scottish salmon-farming industry, claims his group performed a similar analysis of salmon and found that there were lower levels of contamination than the study team found, and that the study's experts were "misleading the public."
The UK Food Standards Agency also challenged the study and stated that the benefits of eating salmon outweighed the possible risks.
In the last 20 years the production of farmed salmon has increased dramatically, and today over half of the salmon sold in the world are raised on farms in North America, Europe or Chile.
© 2004 Animal News Center, Inc.
Farmed salmon carry about ten times more cancer-causing chemicals than wild salmon, according to a new study.
The study, conducted at Indiana University, Cornell University and the University of Albany, examined the levels of 14 toxins, all likely to cause cancer in humans.
The two metric tons of salmon used in the study were purchased in 16 cities in North America and Europe.
The toxins examined included industrial pollutants known as polychlorinated biphenyls (PCBs) which have been found to cause cancer in humans and have been linked to developmental defects, including decreased intelligence, in children.
PCBs were highest in fish from Scotland and from the Faroe Islands near Scotland.
The study's authors believe that PCBs from the manufacture of paints and flame retardants and from waste incineration find their way into small fish that are caught and processed into food for the farmed salmon.
Farm-raised Atlantic salmon - similar to the fish found at Scottish farms - were found to have significantly higher levels of 13 toxins compared with wild Pacific salmon.
According to David Carpenter of the University at Albany, although salmon is rich in omega-3 fatty acids which protect against heart disease, people who have a low risk of heart problems should actually avoid eating salmon, due to the high levels of PCBs in the fish.
Robert Lawrence, a public health expert from Johns Hopkins University in Baltimore, agreed.
"It might be good for middle-aged men, but not for childbearing women and children," he said.
Lawrence added that salmon on US farms are fed recycled fat from slaughtered animals, including cows; and because they are consuming material from higher in the food chain, which might already have high levels of PCBs, the salmon have a greater chance of having high levels of PCBs themselves.
Carpenter believes that if farmers fed the salmon a vegetarian diet - substituting soybeans or flaxseed for fish protein - the levels of PCBs in the fish would be reduced.
Flaxseed oil is also rich in Omega-3 acids and could be used by itself, as a substitute for salmon, by those seeking to increase their heart health.
Based on the United States Environmental Protection Agency's recommended maximum intake of organochlorides - of which PCBs are a part - most consumers would have to limit their salmon consumption to just two ounces per month of Scottish or Faroe Island salmon, or eight ounces per month of uncooked farmed salmon from other European or American markets.
In comparison, eight ounce servings of wild salmon could be consumed as many as eight times in a month.
The salmon-farming industry is a significant source of jobs and revenue in Scotland. So far, the Scottish industry has reacted to the PCB scare with outright denial and defiance.
John Webster, a spokesman for Scottish Quality Salmon, representing the Scottish salmon-farming industry, claims his group performed a similar analysis of salmon and found that there were lower levels of contamination than the study team found, and that the study's experts were "misleading the public."
The UK Food Standards Agency also challenged the study and stated that the benefits of eating salmon outweighed the possible risks.
In the last 20 years the production of farmed salmon has increased dramatically, and today over half of the salmon sold in the world are raised on farms in North America, Europe or Chile.
© 2004 Animal News Center, Inc.
Use the feedback form below to submit your comments.
Use the form below to email this article to your friends.
