With all the wonderful things fish oil can do to help you Be smarter, Fight cancer and Improve depression, I wasn't at all surprised to learn it may also protect your heart from exposure to pollution. There is very little doubt in my mind that omega-3 fats are the single most important nutritional deficiency in the United States. There would be a massive improvement in our health if more people started consuming more of this vitally important animal fat. There is quite a bit of confusion regarding omega-3 fats though and many people believe that flax oil is superior to fish oils. Unfortunately flax oil is a shorter chain omega-3 fat called ALA. Your body must take it through two major conversions before it becomes the important DHA omega-3 fat that provides most all of the benefits of omega-3 fats. Unfortunately most people have a serious impairment of the enzyme (delta-6 desaturase) that converts the ALA to DHA. This is one of the primary reasons why I promote fish and cod liver oil so strongly. While we all need ALA, I believe it is best obtained from organic freshly ground flax seeds and only as a supplement to, never as a replacement for fish or cod liver oil. There is even suggestion that those that use flax oil instead of fish oil will actually worsen their health problems. Fish or cod liver oil is really the only "supplement" I routinely take. I put supplement in quotes because I really don't believe that fish or cod liver oil is a supplement at all, but rather is a food. The unfortunate reason the extracted oil is a superior option to fish itself for most of us is due to the contamination of the fish supply with mercury and PCBs. The trick about fish oil is choosing the best one for your health. And, to help you make the right decision, you'll want to review my FAQ page chock full of links to more articles about the benefits of fish oil and my recommendations. I would advise you to: 1.      Make sure that your brand is free of mercury and PCBs. This will not be on the label so you will need to: Contact the manufacturer for their analysis Review an independent third party that has analyzed the product Hire a company to test the product yourself 2.      Confirm that there are very low oxidation products in the cod liver oil. Cod liver oil has long-chain unsaturated fats (primarily EPA and DHA) and they are very susceptible to oxidation or damage. If the oil is not processed properly damage will occur. Many years ago nearly all the fish oils were oxidized. That is why when you mention cod liver oil to most anyone they turn up their nose in disgust. Typically, they only taste bad when they are oxidized. 3.      Make certain your cod liver oil has therapeutic levels of vitamin E in it. Because fish and cod liver oils are very susceptible to oxidation and rancidity, nearly all manufacturers insert a small amount of one unit of vitamin E per teaspoon. This is sufficient to prevent oxidation of the fish oil in the bottle. However, after you consume it this is woefully inadequate. Your body will tend to oxidize the fish oil and much larger doses of vitamin E are needed to prevent the fish oil from going rancid in your body. There are a number of high-quality fish/cod liver oils on the market. Many of you know I recommend Carlson's. If you can't find that in your local health food store we do carry it on our site for your convenience.