*This one's for you mom :) There is a lot of buzz around essential fatty acids (EFA's), monounsaturated fatty acids (MUFA's), and polyunsaturated fatty acids (PUFA's) right now in the nutrition world. If you don't know much about these terms, let me spare you the boring diagrams of hydrogen and carbon atoms, and let me put it in terms you can fully understand without getting too scientific-y about it. (Scientific-y being the "technical" definition).
The food industry, I'm going to say the proverbial "they" so bare with me, has been talking up all the benefits of PUFA's and MUFA's, and don't get me wrong, there are many benefits, but as they've been glorifying these fatty acids, they've also been downplaying their saturated fat sisters. This article isn't about saturated fats though, that's for another day.
The bottom line about unsaturated fats, though providing many benefits in small doses, are unstable. Have you noticed that your olive oil is liquid at room temperature and your coconut oil is solid? This is because, now here is where I have to get scientific-y, saturated fats have the maximum number of hydrogen atoms attached to every carbon atom in its chain, therefore it is stable. Unsaturated fats however, have gaps in their chains. If it has one gap, it is a monounsaturated fat, and if it has two gaps, it is a polyunsaturated fat. Because of these gaps, they are unstable, thus making them liquid.
Ok, so who cares? Well, everyone should care in my opinion. If something is unstable outside of the body, it is unstable inside of the body. When PUFA's are consumed in high amounts, they are incorporated into the cell membrane making your cells fragile and prone to oxidation, in turn causing inflammation and stress internally. This is seen with the typical American diet composed of high levels of omega-6 compared to lower levels of omega-3's. The optimal diet for your health is to be consuming a 1:1 ratio of omega-6 to omega-3, but in small doses.
It would be wise to stick with more MUFA's, like olive oil, and high grade saturated fats like coconut oil or grass-fed butter, than to be consuming high amounts of PUFA's, which are found in vegetable oils like corn, safflower, and cottonseed. These vegetable oils are usually rancid by the time they hit the grocery store shelf from undergoing extreme processes to extract the oil from them. You would never eat a bowl of cottonseeds, so why are you consuming its oil? Furthermore, when they are heated, the vegetable oil Jekyll turns into Hyde, and the oil goes from an unsaturated fat, to a literally bent out of shape trans fat.
That's right, every time you cook with one of these "healthy" fats, you are ingesting trans fats, which is short for a fat that has undergone a transfiguration, and not in a good way. This is not the fat phoenix rising from the ashes, this is more like the Frankenstein of fats.
What does this all mean?
Start to incorporate more fats in your diet and start to purge your diet from excess PUFA's. Choose high quality fats like coconut oil, grass-fed butter, and extra virgin olive oil (not heated), and start to stay away from oils that include, but are not limited to: canola, grapeseed, cottonseed, safflower, and corn.