Be aware that only about one-third of the oil from fish is rich in EPA and DHA. Many supplements also contain vitamin E or other antioxidants to stabilize the oils and prevent them from becoming rancid. If you choose to buy a fish oil supplement, check the label carefully to see if it recommends refrigeration to prevent spoiling.
Most brands of fish oil have been proven safe, free of detectable traces of mercury, and do not contain unsafe levels of PCBs (polychlorinated biphenyls), a toxin and pollutant believed to pose various health threats.
To avoid contaminants in an unrefined supplement, it's best to choose a fish oil supplement made from small, oily fish like anchovy, sardines, or menhaden.
This content originally appeared on doctoroz.com