The majority of restaurants serve farmed salmon because it is cheaper, but a study published in the Journal of Nutrition shows that it is not the healthiest choice. Farmed salmon is raised in cramped pens where pathogens are rampant, toxicity of the water is common and the fish are fed red dye pellets to color its flesh to make it resemble wild salmon.

Researchers analyzed the risk-benefit ratio based on levels of contaminants like dioxins, PCBs and chlorinated pesticides versus omega-3 fatty acid levels. While farmed salmon is higher in omega-3s, it is also significantly higher in these toxins (about 10 times) which can produce birth defects, lower IQ, and cause cancer. They determined the following based on origin of the salmon: "consumers should not eat farmed fish from Scotland, Norway and eastern Canada more than three times a year; farmed fish from Maine, western Canada and Washington state no more than three to six times a year; and farmed fish from Chile no more than about six times a year. Wild chum salmon can be consumed safely as often as once a week, pink salmon, Sockeye and Coho about twice a month and Chinook just under once a month."

How can you tell if the salmon is wild or farmed if the package does not indicate either? Any salmon labeled "Atlantic" is farmed because commercial Atlantic salmon fishing no longer exists due to the depletion of stocks. The only way to obtain wild Atlantic salmon is to catch it yourself during the short quota salmon season in places like Atlantic Canada. Anything labeled "Alaskan salmon," on the other hand, is by definition wild salmon.

1. Foran JA et al. Quantitative Analysis of the Benefits and Risks of Consuming Farmed and Wild Salmon. J. Nutr 2005 135:2639-2643

Cornell University