- Food and Cooking
The Differences Between Saturated, Monounsaturated and Polyunsaturated Fats
Saturated fat and monounsaturated fat and polyunsaturated fat, oh my! Have you heard these terms before? I hear them all the time because I read ingredient labels and books on healthy eating. But I think most people don't know anything about these kinds of fats, except they should all be avoided. But that isn't necessarily true. The "experts" have us brainwashed into thinking that all fat is bad and the market for "low fat" and "fat free" is thriving.
Before we talk about the health benefits or drawbacks, let's figure out the difference between these three types of fat. Technically speaking it all comes down to the chemical structure. The best information I have read on this comes from a wonderful book called "Real Food" by Nina Planck. On page 168 she describes the differences.
"All fatty acids are strings of carbon atoms encircled by hydrogen atoms. When every carbon atom bonds with a hydrogen atom, the fatty acid is saturated. If one pair of carbon atoms forms a bond, the fatty acid is monounsaturated. If two or more pairs of carbon atoms form a bond, the fatty acid is polyunsaturated. A carbon-hydrogen bond is known as a saturated or single bond. A carbon-carbon bond is called an unsaturated or double bond."
Is that clear? For me that is pretty scientific and science was never my strong subject in school. I think it is more important to remember which are the good fats and which are the bad fats as well as what each fat does for our bodies. Some fats are actually very good for you. Knowing which fats to consume liberally and which fats to avoid is the key to good health.
All fats contain some of each kind of fat, but these fats are classified by what they contain the most of. Examples of saturated fats are beef, butter, coconut oil and chocolate. Examples of monounsaturated fats are olive oil, lard, and bone marrow. Examples of polyunsaturated fats are corn oil, sunflower oil, and safflower oil as well as partially hydrogenated oils.
So which fats are good for you and which are not? Well it depends to some extent on what you do with the fat. Unsaturated fats should not be heated, although monounsaturated fats can withstand heating at low temperatures. When polyunsaturated fats are heated it causes them to become oxidized. As Planck put it on page 169 "Oxidized fats contribute to cancer and heart disease." Yikes! When you buy fast food or chips, you can be sure those foods were fried in polyunsaturated fats at a very high heat causing them to oxidize. That is why they are so bad for you. (OK, one of the reasons anyway.) Saturated fats are best for heating.
A good rule of thumb to remember is that traditional fats are good for you and manmade fats are not. Think about how people used to cook. They used butter from the cow in their backyard and lard from the pig that was butchered in the fall. These kinds of fats are mostly monounsaturated fats (which are good for you) which lowers LDL (the bad kind of cholesterol). Saturated fats actually raise HDL (the good kind of cholesterol) as well as fight viruses and provide our bodies with essential vitamins. Polyunsaturated fats lower HDL, especially those that are cooked. Our bodies do need some polyunsaturated fats, but one of the problems is we consume way too much of it. Try to get your polyunsaturated fats from fish oil, flaxseed oil and walnut oil and avoid the other kinds unless eaten cold.
So there you have it; some of the key differences between saturated, monounsaturated and polyunsaturated fats. Hopefully we can all remember the fats we should avoid and the fats we should consume. I for one am very happy to figure all this out because now I don't have to feel guilty about eating butter.