Is Farmed Salmon Safe to Eat?
By Gloria Tsang
The American Heart Association
recommends eating
fish/salmon and their products to prevent heart disease. On
the other hand, recent media reports indicate that some fish and
farmed salmon contain toxic substances.
What are PCBs?
Polychlorinated biphenyls (PCBs) are mixtures of up to 209 individual
chlorinated compounds. There are no known natural sources of PCBs.
PCBs are either oily liquids or solids that are colorless to light
yellow. PCBs have been used as coolants and lubricants in transformers,
capacitors and other electrical equipment because they don't burn
easily and are good insulators.
The manufacture of PCBs was stopped
in the United States in 1977 because of evidence they build up
in the environment and can cause harmful health effects. However,
PCBs persist in the environment. Fish absorb PCBs from contaminated
sediments and from their food.
Farmed salmon under the
gun
• In January 2001, BBC News produced a program "Warnings
from the Wild: The Price of Salmon." The program cited a
pilot study conducted by Dr. Easton with the David Suzuki Foundation.
The study found that farmed salmon and the feed they were fed
appeared to have a much higher level of contamination with respect
to PCBs, organo-chlorine pesticides and polybrominated diphenyl
ethers than did wild salmon. It concluded that it seems that contamination
in farm fish comes from the feed. (David
Suzuki Foundation)
• In July 2003, the Environmental Working Group (EWG) released
a report stating that farmed salmon purchased in the United States
contain the highest level of PCBs in the food supply system. In
the report, EWG reported that farmed salmon have 16 times the
PCBs found in wild salmon, four times the levels in beef and 3.4
times the levels in other seafood. EWG recommends that consumers
choose wild instead of farmed salmon and eat an 8-ounce serving
of farmed salmon no more than once a month. (EWG
Report)
• In January 2004, Science warned that farmed salmon
contain 10 times more toxins (PCBs, dioxin, etc.) than wild salmon.
The study recommends that farmed salmon should be eaten once a
month, perhaps every two months, as they pose cancer risks to
the human beings. (Science journal)
Farmed salmon PCBs
• Fishmeal/Feed: Studies found that the fishmeal fed to
farmed salmon is highly contaminated with PCBs.
• Farmed salmon are "fatter." Farmed salmon are
generally bigger in size and contain more fat than wild salmon.
PCBs are stored in fat and remain there for an extended period
of time; therefore, farmed salmon contain more PCBs.
Government PCB guidelines
The average level of PCBs in salmon is 0.027 ppm (parts per million).
• FDA: The current FDA limit
of PCBs in all fish is 2 ppm.
• Health Canada: The current Health Canada's guideline for
PCBs in fish is 2 ppm.
• EPA: The Environmental Protection Agency guideline on
PCBs is much stricter. It recommends that no more than 8 ounces
per month of fish with PCBs level between 0.024 to 0.048 ppm should
be eaten.
What does this mean? There is an
obvious discrepancy in the limit set by various health agencies.
Dr. Mark Woodin of Tufts University notes that even if the strict
EPA guidelines were known to be the right ones, they are based
on the amount of PCBs that are thought to be capable of causing
one additional cancer case in 100,000 people over a 70-year lifetime.
Don’t give up on fish
So don't give up fish and salmon completely. It is a known fact
that fish and salmon offer benefits in heart health. The benefits
to heart health may outweigh the risk of getting cancer from eating
farmed salmon. Choose a variety of fish and include them in a
healthy well-balanced diet.
• Trim the skin and the
visible fat, as PCBs are stored in the fatty portion.
• Prepare your salmon to reduce a significant portion
of fat, such as grilling and broiling.
• Try canned salmon, as almost all of them are wild salmon.
© Gloria Tsang
Gloria Tsang, R.D., is the chief
editor for HealthCastle.com,
a one-stop site for reliable nutrition information and tips. HealthCastle.com’s
main focus is on preventive health, with popular topics including
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