Seafood for the Future Blog, Aug. 9, 2010
Here’s a question we recently received: Is farmed salmon really as safe to eat as wild salmon? …The short answer is yes.
Dr. Charles Santerre of Purdue University, whose area of expertise deals with women and children and their sensitivity to toxins, states that, “The best choice for pregnant women is farmed or wild salmon. These fish are high in healthy nutrients and low in pollutants. Farmed salmon is more affordable and available year round. The concerns over PCBs in farmed salmon have been evaluated by experts and found to be insignificant compared to the health benefits.”
Santerre puts into context the definitive study on PCBs and other contaminants in Pacific salmon (wild) and Atlantic salmon (farmed): Ronald A. Hites et al., “Global Assessment of Organic Contaminants in Farmed Salmon,” Science 303, no. 5655 (January 9, 2004): 226-229. (Note that the term “organic” is used in the chemical sense, not the agricultural sense.)
The Hites paper specifically begins saying, “…our preliminary study showed no significant difference in methylmercury levels between farmed and wild salmon.”
Hites found the average PCB level in farmed salmon to be 37 parts per billion (ppb), and the average PCB level in wild salmon to be 4 ppb. Compare this to the tolerance limit set by both the FDA and Health Canada: 2000 parts per billion.
The US EPA has a lower reference dose is based on the actual consumption rate and one’s body weight. For 132 pound person eating 12 oz. of cooked salmon per week, this limit is 50 ppb, according to this paper by toxicologist Charles Santerre: Charles R. Santerre, “Balancing the risks and benefits of fish for sensitive populations,” Journal of Foodservice 19, no. 4 (2008): 205-212.
Santerre advises that, in order to minimize PCB exposure regardless of species or level, cook the fish and cut off the skin.
Furthermore, Santerre notes that, “Americans receive 42% of dioxin-like compounds (which includes some of the PCBs) from meat products; 17% from dairy products; 12% from fruits and vegetables; 10% from poultry and eggs; 13% from other foods; and only 8% from fish products. Thus, when eating fish and not one of these other foods, consumers may actually be reducing their intake of dioxin- like compounds including PCBs.”
