Cholesterol is one of the misunderstood outsiders of the nutritional society. If cholesterol was a person, it would be the kid who plays guitar, cleans his room, builds epic Lego forts, can fix a lawnmower engine and gets along with his parents...except he wears all black so people never look past the exterior and judge him as scary and weird. In fact, the next time someone picks on you for being different, say to yourself “I'm just like cholesterol”.
If you have ever read an article or blog post on cholesterol, you already know its importance in the structure of all steroid hormones, which is good because we need these hormones like testosterone, estrogen, progesterone, cortisol, aldosterone and the body's synthesized version of vitamin D. These hormones are necessary for tissue growth, bone density, energy production, fluid balance and calcium absorption among others. I don't know about you but I want proper function of all of those processes!
Some other neat facts regarding cholesterol is that the brain is made up of about 25% cholesterol and synthesis of cholesterol in the brain occurs during sleep, which also aids in memory. Cholesterol is also a precursor to bile, which we use to emulsify fat that we eat so it can be digested and absorbed.
So cholesterol is great and I should eat as much of it as possible........? Hold your horses because to understand how much and what types of foods to eat, you need to understand why cholesterol has been demonized. Those who say that you should eat as little saturated fat and animal products as possible to limit cholesterol production may not even know that your liver will make cholesterol. Your body will make cholesterol from a compound called Acetyl CoA. This compound is produced when you eat fat OR carbohydrates and is then used within cells to make ATP, which is our most basic form of energy in the body. So even if you ate a very low-fat diet, your body would make all the cholesterol it needs (or try to at least) from carbohydrates. This should be a pretty good indicator to you that cholesterol is not only vital but good for us; our body will try to make it any way it can!
Yep, got it, cholesterol is great AND vital and now I can eat as much as I want? Keep holding those horses because now we get into the really interesting stuff.
I learned relatively recently myself that there is no such thing as good cholesterol and bad cholesterol. There is only one type of cholesterol. What is labeled “good” is High-Density Lipoproteins(HDL) and the “bad' would be Low-Density Lipoproteins(LDL). The name of these two lipoproteins should clue you in that they actually aren't even cholesterol; what they are is the cholesterol carrier. Before I start italicizing this entire article for effect, here is a basic rundown of HDL and LDL.
*These two lipoproteins are carriers for cholesterol, fat and vitamins.
-LDL transports cholesterol, fat and fat soluble vitamins(K,D,A etc) to cells for bone formation, blood clotting and protection against heart disease. Vitamin A even helps prevents calcification of arteries.
--HDL moves cholesterol, fat and vitamins unused or excess from cells back to liver for reprocessing so they do not float around in the blood stream
How the Body Uses Cholesterol
Cholesterol is sent from the liver in LDL to various cells in the body. Cells that use cholesterol, fat and vitamins have receptors on their cell walls that “grab” the nutrients from LDL, and then pull them into the cell to use for energy production and other processes as listed above. HDL is available in the blood stream for uptaking excess amounts of the cholesterol and fat unused by the cell and bringing them back to the liver for disposal. This is simplified but just remember: LDL from liver to cells, HDL from cells back to liver.
The Potential Problem
If our receptors are working well, we are taking up plenty of the nutrients from our LDL and if our HDL is high enough, all the excess is carried back to the liver and out of the blood. The potential problem is when our LDL receptor sensitivity decreases. LDL receptor activity can be low from a genetic defect or from down-regulation within the body. When activity is low, the LDL particles float around in the bloodstream with nowhere to go and eventually oxidizing the cholesterol they carry. This is similar to rust forming on metal, where oxygen causes free radical formation on a particle or compound and damages its structure. When LDL sits in the blood and oxidizes, the cholesterol then accumulates in arteries, causing decreased fluid flow and increased blood pressure; this hardening of the arteries is called artherosclerosis. So it isn't just the LDL that is the problem, it is the receptor activity and the oxidation that matter most.
Corn Oil Is NOT Your Friend
Take a dish of corn oil and place it on a table at room temperature for 6 months. Do the same next to it with some coconut oil. At the end of the 6 months, look at and smell these two fats and tell me which one you'd rather eat. Let me save you time and trouble: it would be coconut oil.
Saturated fat has received a really bad reputation as an artery clogger and said to increase blood triglycerides. Well, that is called the lipid hypothesis and to tell you the truth, there isn't much science to back it up. It makes logical sense, eat more fat and cholesterol, get more fat and cholesterol in your blood. Since no one is going tell you this, let me do you a favor:
-Before 1920, heart disease was very rare in the US
-As of 2000, heart disease caused around 40% of all US deaths
-From 1910 to 1970, animal fat consumption decreased from 83% to 62% of fat in US diets
-Butter consumption during this same time dropped from 18lbs per person per year to 4lbs
-Dietary cholesterol in this same time period only increased 1%
-Fat from margerine, shortening and refined oils increased 400%
-Sugar consumption increased about 60%
*Excuse me, but I thought heart disease was caused by eating animal fats and cholesterol? This shows a decrease in animal fat and cholesterol with a huge increase in refined oils and sugar. What's wrong with this picture?
This takes us back to the corn oil ( I hope you remember my analogy). These “heart-healthy” refined oils are loaded with polyunsaturated fatty acids (PUFA's). These are the so-called good fats that we should be eating in place of grass-fed butter and meat, free range eggs and coconut oil. The issue with these fats is that they are prone to rancidity, the same oxidative damage discussed when LDL just floats around in your blood stream with nowhere to go. Loading up on these easily damaged fats puts us at greater risk of oxidized LDL in our blood. The oxidized PUFA in our blood stream also has the potential to damage the protein in the receptors on our cells, meaning we uptake less of the cholesterol and fat and leave more to sit in the blood.
Does that mean we shouldn't eat any? No, but it should not be your only source of fat!
Saturated fats, on the other hand are very rancid resistant. Coconut oil pretty much WON'T go bad, which is why it is such a good choice to cook with and eat. Unlike processed oils that seem stable, smell clean and look pure, they are actually highly refined, filtered and often perfumed to hide the fact that they are old, oxidized and unstable fats. If an oil needs to be refined and perfumed to make it appealing to eat, that should be a red flag that it isn't a healthy product.
Here are a couple of factual nuggets to chew on:
1. Studies have shown that giving someone corn oil instead of butter may reduce cholesterol. However, oxidation of cholesterol goes up which is contributing to the development of artherosclerosis.
2. Studies have shown that substituting corn oil with butter led to 25% of the risk of heart disease compared to the corn oil-only group.
-The scientific response to this is often that the only reason people ingesting corn oil had higher heart disease risk is because they already HAD it or were prone to having it! That's like saying your car didn't go faster because you stepped on the gas, you were probably just going downhill already.
I hope the cholesterol confusion is clearing for you. We've seen that cholesterol itself isn't always the culprit, it is the ultimate fate of where the cholesterol goes that is cause for concern. We've also covered the benefits of eating quality saturated fats and how excess consumption of refined oils actually contributes to unhealthy cholesterol metabolism.
In the second part of this article I will discuss how to interpret blood markers of cholesterol and some dietary changes you can make to improve your cholesterol health.