Essential Fatty Acids are certain special oils (fatty acids) which are absolutely essential in the maintenance of human health. They are often calls the "good fats", or the "healthy fats". Before going into more detailed information about the types of Essential Fatty Acids, I want to mention that certain fish are a good source of essential fatty acids called EPA and DHA. If you are eating these kinds of fish you are probably getting enough of these essential fatty acids.
Note Cod liver oil is a popular supplement but is not a good source of some of the Essential Fatty acids needed for optimum human health. It's therefore not recommended as a source of Essential Fatty acids. Cod liver oil is a good supplement of Vitamin D, a vitamin that has been found to be deficient in many people, and low levels of which may increase risk for many types of cancers.
Essential Fatty acids can be purchased in gel caps. The purpose of taking Essential Fatty acids on a regular basis is to obtain a therapeutic dose to help the body Heal and prevent or reverse inflammatory processes in the body. Essential Fatty acids have been found to be effective in most circumstances with depression and possibly other mental illnesses, and certainly implicated in a whole list of inflammatory diseases.
Its important to note that the Fish Oil gel caps are often a source of DHA (docosahaxanoic), and EPA (eicosapentanoic acid) which are Omega-3 Essential Fatty Acids derived from fish.
There are generally two types of gel concentrations. There is regular concentration, and most recently pharmaceutical grade quality, a much higher concentration. Essential Fatty acids are an extremely popular supplement. It is important to take the correct dosage, and also to consume a supplement which is micro filtered for poisonous heavy metals. Since the source of the oils are often fatty fish, and fatty fish can contain heavy metals, micro filtering or micro-distillation is essential. I recommend taking fish-oil EFAs in the morning with some fruit, preferably a slightly sour fruit to increase absorption, such as an apple, or some sweet and sour jams. Some EFA supplements can give a fish oil after-taste.
Now on to the more detailed information about Essential Fatty Acids. There are two common types of Essential Fatty Acids. Omega-3 Fatty Acids, and Omega-6 Fatty Acids. These terms generally describe the chemical structure.
Omega-3 Fatty Acids mostly come from fish as detailed above
The highest content plant sources of Omega-3 Fatty Acids are:
Note that the Omega-3 Essential Fatty Acids found in plants or nuts is absolutely not the same as those derived from fatty fish. The Omega-3 Essential Fatty Acid from flax seed is called alpha-linolenic acid or ALA for short. ALA gets converted in the body to EPA and DHA. However this bodily conversion may be very low, between 1% and 10% and very negligible in men.
In addition, the refined oils of corn, safflower, sesame, and sunflower are linked to promoting inflammation.
It is also worth noting that due to the high concentration of Omega-6 in Flax Seed Oil, it is may not be desirable to be consumed without balancing with other Omega-3 oils. Most of our current day food consumption has more Omega-6 than Omega-3 which is undesirable. Eating about 2 tablespoons of walnuts per day is a good way to supplement. Note that walnuts can contain toxins such as molds which can cause adverse reactions in some people and should not be consumed.