Not all fats are created equally, and not all fats are bad for you. Unfortunately we have been inundated with "non-fat" and "low-fat" options for what seems to be every type of food out there. And in the process, we've been a little brainwashed to believe that fat is bad.
But it all depends on the type of fat. We actually need fat in our diet, and especially certain kinds of fat that are beneficial to us in a variety of ways. And yes there are types that are bad for us and should be avoided. The key is to know which is which, and then make good decisions based on that knowledge.
From a chemistry standpoint, it is the chemical structure of the fatty chain that determines its properties, and thus how the human body processes it. In general, there are three types of fatty acids that we see in our foods and food products: saturated, monounsaturated, and polyunsaturated.
Saturated fats are closely bound together and are solids at room temperature. Trans fats are fatty chains that have a trans bond that makes them rigid and thus similar to saturated fatty acids, also solid at room temperature. By being solid at room temp, these fats are very useful for shelf products that do not necessarily need to be refrigerated. These are the fat products found in packaged and processed foods, beef and pork, and butter and margarine. There is evidence that trans-fats increase insulin resistance, have ill effects on our cholesterol levels, increase inflammation in our bodies, and increase the risk of having a heart attack.
Monounsaturated fatty acids (MUFA's) are liquids at room temperature and cloudy and possibly solid when cooled. These contain one carbon-carbon double bond, and they are found in foods such as avocados, almonds, cashews, pecans, macadamia nuts, canola oil, olives and extra virgin olive oil.
Polyunsaturated fatty acids (PUFA's) are liquids when cooled. They contain 2 or more carbon-carbon double bonds, and these are generally broken into Omega-3 and Omega-6 fatty acids, depending on the three-dimensional structure based on the location of the double bond. These fatty acids can be obtained from a variety of sources: Omega-6's and Omega-3's in safflower, sunflower, canola, cottonseed, and soybean oils, Omega-3's in certain nuts (walnuts) and in fish & shellfish.
There are 2 primary Omega-3's that we need to get a lot of - EPA and DHA. These are obtained by eating fish, and can also be consumed in supplements such as fish oil or krill oil. These are the primary fats that have beneficial effects. Conversely, the Omega-6's should be avoided for the most part, as they increase the levels of arachidonic acid, a potentially inflammatory compound.
So here is the take-away message:
Avoid - soybean, safflower, and corn oils; red meat; high-fat dairy products; margarine; processed and packaged foods
Get more - olive oil, avocados, tree nuts, fish & shellfish, and fish or krill oil supplements
There have been numerous studies on the health benefits of Omega-3 fatty acids, too many to list here. In summary, these fatty acids have been shown to decrease heart attacks and sudden death, decrease blood pressure, decrease triglycerides, decrease cardiac arrhythmias, decrease inflammation, be helpful in treating depression and some mood disorders, and potentially beneficial in a variety of cancers.
Again, Omega-3's are plentiful in a typical Mediterranean diet. Eat wisely and eat healthy!
Originally posted Sept. 2015