Fish oil can help lower lipid levels, prevent heart disease and reduce inflammation, but it can also contain dangerous chemicals. Fish oil may contain small amounts of a class of chemical called polychlorinated biphenyls, or PCBs, which have been banned in the United States. You can limit your PCB consumption by selecting fish oil supplements low in these toxins or by eating specific fish less likely to have higher PCB levels.
Certain fish, including mackerel, lake trout, salmon, sardines, herring and anchovies, contain significant amounts of omega-3 fatty acids. Omega-3 fatty acids may help lower blood pressure and the levels of a type of fat called triglycerides. As a result, they are often used to help prevent heart disease and stroke. The fats found in fish oil may also aid in the treatment of psychiatric disorders, such as attention deficit hyperactivity disorder, depression and psychosis. Fish oil may also help in treating diabetes, asthma, psoriasis, kidney disease and osteoporosis. Supplements containing distilled fish oil are commercially available for people who are looking to benefit from fish oil without regularly consuming fatty fish.
PCBs are members of a broad family of man-made chemicals called chlorinated hydrocarbons that were made from 1929 until they were banned in 1979. They were used for hundreds of commercial and industrial products, including electrical equipment, paint, rubber, plastics, dyes and carbonless copy paper. PCBs were banned in the United States in 1979 because of their negative health effects. PCBs increase the risk of developing cancer, including liver cancer and malignant melanoma. They may also weaken your immune system, damage your nerves and affect fetal development.
PCBs and Fish
Although PCBs have been banned for years, they can still be found in some bodies of water, particularly the Great Lakes and the Mississippi River. Smaller fish absorb some of these PCBs, and when they are eaten by larger fish, the PCBs begin moving up the food chain. Fish oil supplements made with these PCB-contaminated fish will also contain PCBs, although the amount varies depending on the type of fish used in the supplement.
Minimizing PCB Intake
Not all fish oil supplements have the same levels of PCBs. According to FishOilSafety.com, fish oil supplements with high levels of PCBs include Now Foods Salmon Oil and Double Strength Cod Liver Oil. In addition, Nature Made Cod Liver Oil and Now Foods Shark Oil were found to have high levels of PCB toxicity. The supplements tested with the lowest PCB levels were from TwinLab and Solgar. If you are concerned about PCBs in fish, focus on eating smaller fish with shorter lifespans, as they are less likely to have a significant accumulation of PCBs in their bodies.
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