Cholesterol…

(If you don’t feel like reading, skip to the bottom to the summary in italics!)

I goofed! Sunday at our Intro to Paleo Session, I shared my cholesterol numbers with everyone like they were something to brag about… BUT I told the wrong numbers! Sorry!

Let’s look at those numbers again and talk about what each one means in detail…

Date: 02/15/2011

Total Cholesterol: 283 mg/dl*

HDL: 88 mg/dl

LDL: 182 mg/dl**

Triglycerides: 61 mg/dl

TC/HDL Ratio: 3.2

*Although this # may seem high, this measurement alone does not tell us much. See below.

**Like Total Cholesterol, this # alone is vague. See below.

Besides scaring you into a heart attack when you learn your numbers, cholesterol serves many vital functions in our bodies. It is the basis of our sex hormones (e.g. testosterone), brain tissue and every single cell in our body. About 20% of your cholesterol comes from your food while the remaining 80% is manufactured by your cells and liver. That’s right. Cholesterol is so important that your body will make it itself… most of it, in fact.

Cholesterol is actually a waxy alcohol (see the -ol ending) that acts as a carrier in the blood. Just like oil and water do not mix, fat cannot float around in our blood stream unaided. Carrier-proteins (e.g. LDL) shuttle cholesterol and triglycerides around in the blood.

For our purposes, cholesterol’s function is to carry triglycerides and cholesterol from the liver TO the cells for energy or fat for storage. Alternately, it also brings triglycerides and cholesterol FROM the cells and fat to the liver for recycling or elimination.

There are several different types of these carrier-proteins in our blood and they are not static. They transform from one kind to the next. We will look at four main types, but know that there are many more. In fact, we do not even know the exact functions of several of the types of cholesterols in our blood.

The most commonly known carrier-proteins that we will discuss are: high-density lipoprotein (HDL), low-density lipoprotein (LDL), very-low density lipoprotein (VLDL), and the lesser known intermediate-density lipoprotein (IDL). As each type performs its job, it transforms into another type.

All triglycerides and cholesterol leave the liver as VLDL first. VLDL is characterized by having mostly triglycerides and some cholesterol. As VLDL travels throughout the blood dropping off triglycerides to either cells for energy or fat for storage, it becomes smaller and turns into IDL.

IDL still has a bunch of triglycerides to drop off, so it continues through the blood shuttling triglycerides to their new home. When it has dropped off a sufficient amount, it transforms into LDL.

LDL drops off both triglycerides AND cholesterol to various cells and tissues throughout the body. It even has a special receptor called LDL receptor that only recognizes LDL.

Okay, let’s talk about the numbers now.

Total Cholesterol

Thirty years ago when total cholesterol was the only lipid we were able to measure, doctors noticed that total cholesterol was elevated in men who had heart attacks. They falsely assumed, however, that total cholesterol  caused coronary artery disease and heart attacks, instead of merely being associated with it.

Several studies over the past 30 years have shown that total cholesterol has little bearing on whether you have a heart attack or not. Several people with a low total have heart attacks every day. So, in essence, total cholesterol tells us nothing about our heart health unless it’s extremely high or low.

High-Density Lipoprotein (HDL)

HDL, a.k.a. “good cholesterol”, is the carrier-protein that picks up triglycerides from cells and takes them back to the liver for repackaging or reuse. Although “good” and “bad” cholesterol is not so cut and dry, black and white, it does serve the general function here.

There are several sub-types of HDL, but the consensus is currently out on their significance. Generally, we don’t want too little HDL. Below 50 mg/dl for women and 40 mg/dl for men is a bad sign according to the American Heart Association.

As you can see, mine was 88mg/dl.

You can increase your HDL number by diet and exercise. The best foods to eat are quality fats, like fatty fish (salmon, sardines, mackeral) or taking a quality fish oil (Nordic Naturals, Carlson’s) or grass-fed meat. Exercise and drinking wine (red, especially) is also known to have beneficial increases in HDL.

Low-Density Lipoprotein (LDL)

LDL has been deemed the “bad cholesterol” because it shuttle triglycerides TO cells for use. By itself, this is a very necessary function. LDL can be damaged, however, and deposit those triglycerides in artery walls instead, leading to atherosclerosis. LDL becomes damaged through oxidation by high blood sugar… “carmelized” if you will. This is how diabetes, heart disease, and metabolic syndrome all have common themes.

Instead of worrying about lowering your LDL number, it’s more important to focus on preventing damaged LDL through lifestyle factors like controlling your blood sugar and not smoking.

My LDL number was 182 mg/dl, which may seem high, but read on.

The LDL number by itself is not enough to tell us much because its subtypes have significance on whether we are suffering damage or not. Unfortunately, a general lipid panel does not tell us the different subtypes. Instead, it measures total cholesterol, triglycerides and HDL because those are cheap tests. The LDL is figured from a mathematical equation.

Let’s think of LDL as A-LDL and B-LDL. Your genetics play a large role in determining the ratio of these two subclasses. A-LDL is large, fluffy, and benign. They resist “carmelization.” B-LDL is small, dense and dangerous. B-LDL has a tendency to become “carmelized” easier and deposit in artery walls instead.

What does diet have to do with this? A lot.

The standard high-carbohydrate, low-fat diet that most Americans eat almost guarantee that more small, dense B-LDL’s will be formed. So… even if you lower your total cholesterol and your LDL with such a diet, you are at a larger risk of developing heart disease if all of your LDL’s are of this type.

A lower-carbohydrate, higher-fat and low-sugar diet, however, has the opposite effect in producing large, fluffy, resistent A-LDLs. So, even if your LDL number is high… if they are mostly A-LDLs, you are okay.

My number is inconclusive. They could all be B-LDLs, yes, but I doubt it because of my high HDL and low triglyceride number.

Triglycerides

Triglycerides are the energy form of fat that is also used for storage. Heart, muscle, and your body (when give the opportunity) prefer triglycerides over sugar for fuel. With elevated insulin levels our bodies cannot use triglycerides for fuel and store them away as fat thighs, bellies, or backs instead. We also store triglycerides in and around our organs. That’s how men can have huge guts that are hard.

High triglycerides put you at a larger risk for experiencing a heart attack than LDL or Total Cholesterol numbers. Below 100 mg/dl is best.

Interestingly, high triglycerides come from a diet high in carbohydrates and poor insulin sensitivity instead of a high fat diet.

Mine were 61 mg/dl. Not too shabby.

In summary, cholesterol is a very important class of lipids that serves vital functions in our bodies. The various subtypes of cholesterol that we measure: HDL, LDL, VLDL, IDL either carry cholesterol and triglycerides TO cells and fat tissue or bring them FROM cells and fat to the liver. We call the kind that takes triglycerides TO cells LDL, a.k.a. the “bad kind”, while the scavengers that bring triglycerides FROM the cells to the liver is the “good kind”, HDL.

Total cholesterol is a vague measurement that does not tell us much. It can vary greatly between people because of genetic differences.

LDL levels are not an independent risk factor for heart disease as was once thought. Instead, oxidized LDL (B-LDL) that is small and dense is very atherogenic while large fluffy A-LDL is benign. It is not possible to know the ratio of your LDL without a specific, and expensive blood test.

From current research, HDL and triglyceride levels have more impact on heart disease risk than LDL levels. Optimal levels of HDL are above 40 mg/dl for men and above 50 mg/dl for women. Triglyceride levels below 100 mg/dl are recommended, but below 70 mg/dl is even better.

Reducing the amount of carbohydrates and hydrogenated oils while increasing the quality of fats (more omega-3 fats) in your diet will decrease triglycerides and increase HDL levels. Genetics also play a large role in your cholesterol numbers.

I’ve never had my blood lipids checked before, but from the this record, I’d say my Paleo diet has suited me well over the past year and 1/2. 🙂

For more info, read this paper:

Ramsden CE, Faurot KR, Carrera-Bastos, P, Sperling LS, de Lorgeril M, Cordain L. Dietary fat quality and coronary heart disease prevention: a unified theory based on evolutionary, historical, global and modern perspectives. Curr Treat Options Cardiovasc Med; 2009;11:289-301.

The following books are also great:

For the nerds:

  • Good Calories, Bad Calories by Gary Taubes. A technical book about “fats, carbs, & the controversial science of diet and health”.

For everyone else:

  • Why We Get Fat, also by Gary Taubes. Basically, Good Calories Bad Calories in the easy-to-read format.
  • The Paleo Solution by Robb Wolf. A great mix of science, humor, and real-life experience. He covers everything from food to digestion to exercise and everything in between.

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