Many people are concerned about taking fish oil supplements because of the possible contaminants they may contain. One possible toxin is polychlorinated biphenyls, or PCBs. These are synthetic and were widely used before being banned in the U.S. back in the 1970s. However, during the time they were used, they contaminated the air, soil and water, and are still present today. They are very stable compounds that do not decompose easily.
How PCBs Get Into Fish Oil
Since PCBs are in water, many fish can be contaminated with the compound, thereby transferring it to humans when the fish is eaten or its oil is used in a supplement. Certain types of fish are more likely to be affected by PCBs, especially those who are predators of smaller fish, are fatty, or are caught near industrial areas. Examples of fish to avoid are farmed Atlantic salmon and blue fin tuna.
Dangers of PCB Exposure
The FDA has set a standard for the amount of PCBs permitted in supplements, which is less than 2 parts per million (or two nanograms). Exposure to certain levels of PCBs can cause a multitude of health problems. The National Toxicology Program has deemed PCBs a probable human carcinogen. Increased levels have led to cases of melanoma, liver cancer, gall bladder cancer, gastrointestinal cancers, and brain cancer. Whether or not it is linked to breast cancer is still being determined.
PCBs can also affect the immune system, the thyroid hormones and are unsafe for pregnant women due to the possibility of causing neurological problems and brain issues to the unborn baby.
PCBs are not water soluble, so they cannot be excreted by the body. Therefore, they can accumulate in the body over time. Some types of PCBs can eventually be reduced to a nontoxic form, but that decomposition process can take several years.
Choosing a Safe Supplement
It is nearly impossible to find fish that are completely devoid of all contaminants, but many reputable manufacturers use a distillation process that separates toxins from the pure fish oil, and meet the FDA standards of low PCB levels. So, when purchasing a fish oil supplement, make sure to research it and read the labels to determine that it is as safe, pure and toxin-free as possible.
Summing It Up
Fear of these toxins is no excuse for not taking omega-3 supplements. There are plenty on the market that are safe for consumption and will allow you to reap the many benefits omega-3 offers. As with any supplement, please discuss them with your doctor before adding them to your regimen.