Poly-unsaturated Fatty Acids
An acquaintance asked me whether poly-unsaturated fatty acids are good or bad, and here is my response:
PUFAs (PolyUnsaturated Fatty Acids) are a major, blanket term for many different individual kinds of fats. In this regard, there are only three options for fat to be in (there are other ways of categorizing fats, however, just like you could categorize fruits either based on size or based on color. Either way, you are going to get fats placed into different groups depending on how you categorize.)
So in this regard you have either: MONOUNSATURATED fats, POLYUNSATURATED fats, and SATURATED fats. As you know, saturated fats are considered the “bad” fats (They’re only “bad” if you get too much, which many of us do.) Saturated fats are not essential.
Mono- and poly- unsaturated fats are both lumped under “UNSATURATED” fats– the so-called better fats.
Unsaturated fats include the essential fattty acids, like OMEGA-3 & OMEGA-6 (OMEGA-9 are PUFAs, but not essentail). As their name implies, many of these fats are essential, and polyunsaturated fatty acids can supply those fats that are essential to good health. Most notable are ALA from greens, soybean oil, and flaxseeds; and DHA and EPA from fish oil and cod liver oil. Many people supplement with these oils because they have been scientifically proven to benefit a wide range of health conditions. These are all PUFAs (of the omega-3 variety), and in this case they are good. Most of us get too few (we should eat more dark greens, fish, omega-3 supplemented eggs, and dressings with soybean oil, and take fish oil or flax oil supplements)
Many of the OMEGA-6 oils are PUFAs (some are MUFAs), and they are common in the modern diet. They are essential to physiological function, but if there are too many of these and too few OMEGA-3, they promote inflammation (arthritis, obesity, allergies, etc.) The reason these are so common is that they are the main oils in grains, vegetable oils, eggs, and poultry.
So PUFAs are not bad, they should just be taken in a good ratio. A good way to do this is to buy a bottle of cod liver oil or good fish oil capsules, and/or eat salmon frequently and raw walnuts.
One problem (only a problem b/c of modern processing) with PUFAs is that they don’t have a shelf life. They go rancid easily (unlike saturated fats). So industry has been using “hydrogenation” to create saturated and trans fatty acids out of PUFAs and MUFAs. These new industrial fats don’t go rancid like the unsaturated fats, but they wreak havoc on the body and should be avoided (like the plague for those with heart disease).
In a nutshell: don’t worry about polyunsaturated fats, other than to increase your consumption of the foods mentioned above and decrease the amount of processed foods.