10. Wild Salmon vs. Farmed Salmon
Barbara A. Knuth, Natural Resources, Steven J. Schwager, Biological Statistics and Computational Biology, and research colleagues found in a benefit-risk analysis that consumers should choose wild salmon over farmed salmon unless heart disease is a risk factor. Although farmed salmon has more omega-3 fatty acids, which benefit the heart, it also has much higher levels of chemical contaminates—up to 10 times greater—known to cause cancer, memory impairment, and (in children) neurobehavioral changes. For the person with a history of heart disease, the benefits from eating salmon outweighs the risk of pollutants; however, for children who run the risk of the accumulation of carcinogenic pollutants or for pregnant women who risk damage to the fetus, the risks outweigh the benefits. The researchers found regional differences in contaminants in farmed salmon, with Chilean salmon showing the lowest levels and European (particularly Scottish) farmed salmon showing the highest levels. In general, the net benefits of eating wild Pacific salmon outweigh those of eating farmed Atlantic salmon. The study supports policy and regulatory efforts that would limit pollution of waters, clean up existing pollution to reduce human exposure to contaminants, and require fish to be labeled with the country of origin so that consumers can make informed decisions.