Salmon provides an excellent source of omega 3-fatty acids — a type of fatty acids that Western diets are often deficient in. Omega-3s are believed to have a protective effect against pancreatic cancer and other types of cancer. In addition to omega-3s, salmon (particularly wild salmon) provides plenty of astaxanthin, a carotenoid that gives salmon its pink color and that has strong antioxidant activity. In addition to boasting higher levels of astaxanthin, wild salmon contains lower levels of polychlorinated biphenyls (PCBs), harmful chemicals that are often found in high quantities in farmed salmon. That said, moderation should be practiced also in the consumption of wild salmon. Too frequent or too high a consumption of salmon may predispose you to an excessive exposure to certain toxins — such as mercury and pesticides — contained in fish. The FDA recommends eating fish twice a week, but not more often. Pregnant women and women who are planning to become pregnant should take this advice particularly seriously because the toxins in fish can impair the neurological development of the fetus.