Fish oil is an excellent source of the essential Omega 3 fatty acids, EPA and DHA. They are classed as essential because the body needs them but cannot synthesise them itself and has to obtain them from dietary sources. The Omega 3’s have extraordinary health benefits that have now been validated by studies from all over the world; however, most of us do not get enough of these in our diet. Omega 3’s are found in high quantities in cold water oily fish such as Sardines, Mackerel, Salmon and Tuna but because of the risk of potentially harmful toxins in fresh fish, many people prefer to supplement their diet with fish oil.
There are basically two types of fish oil available; one is extracted from the fatty tissue of fish and the other from the liver of fish, cod liver oil for example. Both types contain the essential Omega 3 fatty acids but cod liver oil can also contain high levels of Vitamin A and Vitamin D and these vitamins can accumulate in the body over time and possibly lead to vitamin toxicity.
Vitamin A is necessary for night vision and helps to fight infection but too much of it can result in severe vitamin A toxicity. Any oil extracted from the liver of fish will contain higher and potentially harmful levels of vitamin A. Vitamin D helps our body to absorb calcium and is necessary for healthy bones and teeth. We can source vitamin D from sunlight as well as from some dietary sources and supplements, but exposure to excess sunlight will not cause vitamin D toxicity. Vitamin D toxicity is most likely to arise from people taking vitamin supplements or fish oil supplements containing vitamin D.
One of the problems with any type of fish oil is the risk of rancidity. As they are highly unsaturated, fish oils can oxidise very easily. This means that without added protection, they can quickly become impure and lead to an increase in the number of free radicals in the body, which could counteract any of the health benefits of taking the fish oil in the first place.
To avoid this problem, it is important when choosing a fish oil to look for one that contains an efficient antioxidant such as vitamin e, tocopherol. This will help to keep the fish oil fresh and prevent it from going rancid, it will also help to preserve the beneficial and protective effects of the Omega 3 fatty acids present in the fish oil.
Some types of cod liver oil have been processed in such a way that all the natural Vitamin A and D has been removed and a synthetic form of vitamin A and D added. This type of oil can increase your risk of suffering from vitamin toxicity. If you are in doubt about the level of vitamins in your body, the only way of finding out is to have your levels tested by your GP.
Pure EPA pharmaceutical grade omega 3 fish oil only contains the natural form of vitamin E, this has been added to help keep the oil fresh both in the capsule and in the body.