So as you may remember, I am taking Food Chemistry. We just concluded a unit on fat and I really want to share with you what I have learned. First of all, not all saturated fat is bad. It is much more complicated than that. Also, you should know that while 90% of the population does better with a lower fat (like 30% of daily calories) diet, 10% of the population does better with a higher fat diet and will actually see a decrease in health if they eat a lower fat diet. By decrease in health, I mean their HDL (good for your heart) levels goes down and their LDL and VLDL goes up (bad for heart health). However, Americans are not told this exception because when you are trying to dissipate information to the masses, it is easier and more successful to make easy to make simple blanket statements.
Now, let me explain why not all saturated fat is bad.
First of all, a fat is also called a triglyceride. It has two main elements. The skeleton of the fat is made of a 3 carbon chain called a glycerol backbone. In essence, it looks like this…
The skeleton is attached to 3 fatty acids. Each carbon connects to 1 fatty acid. We will call the first carbon Position 1, the second carbon Position 2, and the third carbon Position 3.
Now, let’s differentiate between the different fatty acids.
They can be saturated or unsaturated.
Saturated means that the fatty acid has all single bonds and as many hydrogens bonded to it as possible. Unsaturated means that the fatty acid has double bonds, and thus a few less hydrogens than is possible. Unsaturated fatty acids can have one or multiple double bonds, AKA monounsaturated and polyunsaturated.
Polyunsaturated is further divided between Omega 3’s and Omega 6’s. Unsaturated fatty acids tend to raise HDL (good) and lower LDL and VLDL levels. This means that they are good for your heart! However, the ratio of Omega 3s to Omega 6s seems to be important. Too much Omega 6 is possibly detrimental. Sources of omega 3’s include salmon, nuts, flax, and avocado. Sources of omega 6’s include vegetable, corn, soy, cottonseed, sunflower, and safflower oil.
Note: In nature, plants tend to have some unsaturated fats. Unfortunately, unsaturated fats go rancid faster than saturated fats (because of the double bonds). So, food companies like to add hydrogens to the unsaturated fats to make them saturated. This is called hydrogenation (think about how on ingredients lists you see “partially hydrogenated oil”). This is how trans fats are produced. Trans fats actually are the worst fats for your health. They can be found in many packaged and pre-made foods as well as in fast food and restaurants. Check your labels!
Fatty acids can also be short, medium, or long.
Short chain fatty acids are small enough to go straight into our intestinal walls and blood stream. Even if they are saturated, short chain fatty acids do not appear to have negative effects on our HDL and LDL levels. Dairy products like cow and goat milk, butter, cheese, and yogurt have short chain fatty acids, as well as coconut and palm oil.
Medium chain fatty acids also do not appear to have negative effects on our LDL and HDL levels, even if they are saturated. Coconut and palm oil have lots of saturated, medium chain fatty acids.
Long chain saturated fatty acids also need to be broken down and re-assembled by the body. They have been linked to an increased risk of coronary heart disease. Most raise both HDL (good) and LDL and VLDL (bad) levels. Beef and animal fats contain long chain saturated fats.
Remember, though, that trans fats are the worst of all because they lower HDL levels while raising LDL and VLDL levels.
Okay, now that you know all about the different types of fatty acids that attach to the glycerol backbone, I am going to rock your world.
Remember how I said that there are three carbons on the fat’s skeleton and each one holds onto a fatty acid? Well, it turns out that the middle carbon, Position 2, is a bit more important. When our bodies digest fats, we tend to break off the fatty acids at Position 1 and Position 3 from the glycerol backbone. The fatty acid at Position 2 tends to stay attached. Whichever fatty acid is at Position 2 is fully absorbed and metabolized by our bodies. The fatty acids that were at Position 1 and 3 are usually metabolized as well, but sometimes they get bound up by certain ions or molecules and are excreted.
What does this mean? It means that Position 2 is a bit more important for our health than Positions 1 and 3! So, we want to have unsaturated fatty acids at Position 2, or at least short or medium chain saturated fatty acids. Basically, having a “good fat” at Position 2 is awesome and having a “bad fat” at Position 1 or 3 is slightly less bad, because it might get excreted. If it gets excreted, it isn’t going to effect our LDL or HDL levels.
Putting it all together:
Have you wondered why some people say that coconut isn’t bad for you? Although it is mostly saturated fat, the fat that is at Position 2 is unsaturated! Furthermore, the saturated fats in coconut are short and medium chain, which are not harmful.
What about chocolate?! While cocoa butter is mostly saturated fat, the fatty acid at Position 2 is unsaturated!
In essence, try to get your sources of fat from nuts, seeds, avocado, olive oil, salmon and other fish, flax, eggs, coconut oil, butter and milk products (with some portion control) and grass fed meats. Try to avoid hydrogenated oils, vegetable oil, deep fried things, fast food, packaged foods, and above all else… trans fats.
[Disclaimer: While this information is helpful for many people, it can actually be harmful to people with certain conditions. For example, while most people benefit from unsaturated fat, they can actually harm people fighting cancer. In one study, unsaturated fat promoted tumor growth while short and medium chain saturated fats provided the patients with sufficient calories and energy.]