There are 20 different types of fatty acids that the human body needs for optimum health. It can manufacture all but two of those, which must be obtained from the diet and are known as essential fatty acids (EFAs). Essential fatty acids are better known as omega 3 and omega 6 fats. While most people get an ample amount of omega 6's in their diets, intake of omega 3 fatty acids is generally very low.
There are many different types of essential fatty acids; the ones most well-researched for human health are alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA); these are all polyunsaturated fatty acids.
There is much evidence that omega 3 fatty acids, especially, are vital to your health. The EPA and DHA in fish oil are the subject of thousands of studies that clearly demonstrate cardiovascular benefits and reduced mortality rates as primary benefits of these fats.
Omega 3 fatty acids are probably the most important fats for your health. A major reason for this is because they tend to suppress inflammation, a primary cause of many of the degenerative diseases so common today — heart disease, diabetes, Alzheimers, arthritis, and more.
DHA is the most biologically active essential fatty acid. It has been proven to be the main contributor to the cardiovascular protection of fish oil. DHA is used by all cell membranes in your body, especially your brain.
Most of the health benefits associated with omega 3 fats are linked to the animal-based omega 3 fats EPA and DHA, not plant-based ALA. ALA can be converted into EPA and DHA in your body, but only at a very low rate. This makes vegetarian sources of essential fatty acids less desirable.
Seafood, by far, is the best source of omega 3 fats.
Other good omega 3 foods include:
The other primary type of essential fatty acid is linoleic acid, also known as omega 6 fats. Although omega 6’s have acquired a reputation as “bad fats,” they're not inherently unhealthy. However, problems may occur when you consume too many omega 6's compared to the amount of omega 3's you eat.
Omega 6’s can increase inflammation, while omega 3’s reduce it. Excess inflammation contributes to the very diseases which omega 3’s have been proven to help. Both omega 3 and 6 fatty acids are needed for optimal health.
An imbalance of these fats stems in part from a diet high in animal fats and processed foods made with hydrogenated oils (trans fats). Trans fats are metabolized very differently from other fats, and interfere with your body's assimilation of other dietary fats.
For optimal health, you need a ratio of omega 6 to omega 3 fatty acids somewhere between 1:1 and 4:1. The typical American diet contains an excess of omega 6 — having ratios ranging from 10:1 to 30:1!
Good sources of omega 6 fats include:
One should be careful about purchasing vegetable oils, however. Almost all of the corn, canola, sunflower, safflower, peanut and soybean oils in your supermarket have been bleached and deodorized. They're stored at room temperature, in clear containers with no expiration date. This means that the omega 6 fats in these products may well be of poor quality.
Omega 9’s are the most abundant fatty acids of all in nature. They are not considered essential because you can make omega 9’s from other unsaturated fats in your body.
Omega 9’s are found in olive oil, avocados, peanuts and almonds. Interestingly, the oil produced by your skin glands is the same omega 9 fatty acid found abundantly in olive oil: oleic acid.
The only truly “bad” fats are the ones not found in nature: trans fats. The food industry created hydrogenated trans fats by adding extra hydrogen atoms into the molecular structure, creating an unnatural product that your body does not assimilate properly.
It has taken decades, but the health hazards of trans fats has finally made it into the public consciousness. Many manufacturers are now promoting trans fat-free snacks and other processed foods. This still does not make these foods healthy, however. Your best bet is to just avoid processed foods altogether, and you'll avoid trans fats entirely.