The types of fat you eat have a massive effect of your health, and it’s probably not what you think. Typical government agencies and mainstream nutrition advice state that the polyunsaturated fat is the “healthy” fat while saturated fat — and now even monounsaturated fat — is the unhealthy one. But is this actually true?
The Truth About Saturated Fats
Saturated fats have typically been deemed the “bad” fats, but this couldn’t be further from the truth. The original reason that they were viewed as bad fats was because they can increase cholesterol is certain situations. Back in the 1950s, before we knew better, it seemed logical that this was healthy. However, it’s important to understand why something is happening and what it means within the entire context of the body, not just one specific outcome that may or may not matter.
This type of fat can raise cholesterol because it protects the liver and allows it to adequately turn its fat into cholesterol. Cholesterol is extremely important for health. It’s not only an antioxidant but also a key building block for cellular structures, bile acids and steroid hormones. If your cholesterol levels are high, it’s indicative that your body isn’t using cholesterol the way it should (likely based on low thyroid hormone) and therefore your levels of protective hormones like pregnenolone, DHEA, progesterone, etc. are all reduced.
However, it’s not saturated fat that is at fault. Rather it’s the next step of the process — using the cholesterol — that is flawed. Saturated fat, on the other hand, is protecting your liver and keeping it from storing fat, which would result in a disease called non-alcoholic fatty liver disease (NAFLD), which can cause the entire host of symptoms related to Metabolic Syndrome.
Why does saturated fat have this protective effect? They have no double bonds, making them extremely stable, even in high heat and high oxygen environments like the human body. This is also why plants that live in tropical climates (like coconuts) have almost entirely saturated fats. Because they’re so stable, they have the effect of diluting less stable compounds and fats, preventing the damage they can cause. These fats are the preferred fat for the human body and are found in coconut oil, dairy products and beef.
What About Monounsaturated Fats?
For a long time, monounsaturated fats (MUFAs) got a pass as healthy, but recently the AHA has even tried to attack these fats in favor of polyunsaturated fats (PUFAs). MUFAs act much like saturated fats in the body, but are slightly less stable. This is because the monounsaturated fat has one double bond, and double bonds are far more susceptible to breaking down when exposed to heat, light or oxygen (two of which are quite abundant in the human body).
While these fats are less stable than saturated fats, they’re still stable in the conditions found in the human body and have a similarly protective effect as saturated fats. However, because of the one double bond, it’s not a good idea to cook with these fats, as the added heat can cause that double bond to break down into free radical breakdown products. Regardless, these fats are very healthy and are found in avocados and olive oil.
The Dangers Of Polyunsaturated Fats
Finally, we have the polyunsaturated fat, which has multiple double bonds. Remember when we discussed the protective effect of saturated fats on the liver? PUFAs have the opposite effect. They were originally viewed as heart healthy because they have the effect of lowering cholesterol in the blood, but we didn’t know how they worked, which is crucial to understanding if they’re healthy or not.
In truth, the PUFAs are extremely unstable because they have multiple double bonds. This is especially true in high heat, high oxygen environments like the human body, and it’s also why these fats are found in cold climates, like seeds that live underground in temperate climates, and cold water fish. These fats are easily broken down into free radicals and other breakdown products, which damage the mitochondria in cells and prevent healthy metabolism.
When it comes to cholesterol levels, these PUFAs cause the cells in the liver to lose their ability to create cholesterol, and instead the liver stores fat. This creates the disease state called NAFLD, as mentioned earlier, and creates a ton of other health complications. These fats are inappropriate for the human body and should be limited or avoided as much as possible. They’re found in vegetable oils, most nuts and fish oils.
Natural vs Manufactured Trans Fats
One final fat that’s worth mentioning are the trans fats. Typically, these fats are awful for your health (even though the same government agencies that are currently promoting PUFAs used to stick their heart healthy logo on these trans fat sources). However, some trans fats are naturally present in dairy products, and these naturally occurring trans fats can have some benefits to them.
For example, conjugated linoleic fatty acids or CLA are naturally occurring trans fats and have been researched as a metabolism boosting health supplement. While you definitely want to stay away from trans fats in things like margarine, natural trans fats from dairy are safe.
Know Your Fats
Fats are an incredibly important component to your diet, and your body uses them for many different processes. However, it’s important to only consume fats that are appropriate for humans — who have high body temperatures and lots of oxygen. Because of these conditions, saturated fats and mono-unsaturated fats are stable and healthy, while PUFAs are extremely unstable and will cause high levels of inflammation and oxidative damage, eventually leading to diseases like NAFLD.
Trans fats are typically bad, unless they are naturally occurring, like they are in certain dairy foods and beverages. Overall, that means you should include foods like coconut oil, butter, dairy fat, beef, avocados and olive oil in your diet, while avoiding all vegetable oils (like canola, safflower, sunflower, etc.), peanut oils and other nuts and fish oils.