Pretty much everyone who has ever been to a doctor has taken a blood test for a conventional cholesterol panel. It is often paid for by our insurance or employee benefits in an annual check-up. While it is not exactly free, it is as close to it as we can get. Given that, wouldn’t it would be nice to know what use it really isas a health metric? That depends on what it can tell us about our risk of having a heart attack.
The old days compared to now
10 and 20 years ago, we were told (because our doctors were taught) that 1) eating fat raises cholesterol, and 2) the higher the cholesterol the greater the risk of heart attack. Now we know that eating fat does not make us fat. Eating sugar and the wrong kinds of fats (like evil trans fats still found in some margarines or too many omega 6 fats like those found in vegetable oils) creates inflammation in the body that leads to a fat body. We also know that it is not cholesterol but inflammation that puts people at risk for heart attack.
Even the American Dietary Board completely changed its position on cholesterol in 2015, stating that cholesterol is no longer a nutrient of concern. Notice they acknowledged cholesterol is a nutrient, not an evil-doer. The truth is, our bodies need cholesterol. It is a healing agent. If we did not have cholesterol in our bodies we would die. Cholesterol also helps the body make vitamin D and helps your memory.
Given that cholesterol is not the bad guy, why do we even test cholesterol anymore? Is the standard lipid panel a valid metric of anything?
Well, the typical lipid panel – commonly referred to as a cholesterol panel – used today in doctors’ offices everywhere is the same one used 20 years ago. It is indeed flawed. Not beyond usefulness, but we should proceed with caution when considering taking action due to results on this panel.
What is included in the standard cholesterol panel?
The results of this blood test are supposed to inform us about our cholesterol levels, which in turn are supposed to inform us about our risk of heart disease. Many of us have some understanding that if certain numbers are too high – in particular, our LDL or so-called “bad cholesterol” – our doctor will tell us we need to change our diet. Maybe s/he will even recommend that we go on a statin, which is a cholesterol lowering drug.
The typical cholesterol panel in at a typical check-up produces 4 numbers. Following is a list of what those number are and whether or not they are really useful:
1. Total cholesterol:
What it is
Total Cholesterol = your HDL + your “calculated” LDL. The fact that LDL is a calculated figure is important, and I will come back to that.
Useful or not?
Not. For a few years, medical professionals thought that having high total cholesterol increased your chances of having a heart attack. They thought it was a marker of heart disease. This has turned out to be wrong. The data over time has shown that high total cholesterol is not a predictor of heart attacks, heart disease, having a stroke or anything else bad.
Total cholesterol will rise and fall depending on your HDL, which you actually want to be high. If your HDL goes up by 50 mg/dl which is a good thing, your total cholesterol will also rise by 50 mg/dl. Then an uninformed but well-intentioned doctor may try to “treat” this number. So it’s best to ignore Total Cholesterol on the grounds that it is an outdated and meaningless number.
- Action Step: If despite the above info, you or your doctor is worried about this number why not have your inflammation level measured? Inflammation is what causes heart attacks. A HS-CRP test will tell you very clearly how much you have. If the number is below 1.0, you are not at risk of heart attack.
2. LDL (low density lipoproteins):
What it is
Low density lipoproteins, or LDL, are packages that carry cholesterol from the liver to the tissues. LDL is not the actual cholesterol but the transporter. In the old days it was thought that this number needs to be very low or else you will be at higher risk for heart disease and stroke.
Useful or not?
Not. Surprisingly, this is also not a number to worry about, for two reasons:
- LDL come in different sizes. And yes, this is one of those cases where size matters. The good LDL particles are big and fluffy. The bad ones are small and hard. The small, dense particles oxidise easily and will readily stick to your artery walls to form plaque. The big, fluffy LDL particles, though, are harmless. In the old days this was not known, so all LDL were wrongly implicated as unhealthy. Today, there are tests that measure LDL particle size and number.
- Action Step: If you or your doctor worry that your LDL number on a conventional lipid test is too high, you could ask for a LDL particle size and number test as a follow-up.
- In any case, the LDL number you receive on a standard lipid panel is not a real number. It is a number calculated from Total Cholesterol, HDL and triglyceride numbers + estimates from an outdated methodology. The outdated, 50-year-old calculation assumes various things. For example, all people weigh the same, eat the same, etc. But, if you follow a low carb, high fat eating plan, you will by definition modify the lipoprotein composition in your bloodstream. This in turn invalidates the LDL number. It is fiction, essentially, and can safely be ignored on these grounds.
3. HDL (high density lipoproteins):
What it is
High density lipoproteins, or HDL, are vessels that act as a sponges. They sop up cholesterol from blood vessel walls and move it to the liver to be recycled.
Useful or not?
Yes, useful. Unlike LDL, HDL is a real number. And the higher it is, the better.
It is not entirely clear whether it’s the HDL particle size themselves that is responsible for longevity or whether it’s just an associated factor. It is established, though, that high HDL is a reliable gauge that you are doing something right with you lifestyle, particularly with food. While HDL values are influenced by genetics, lifestyle has a potent impact.
What should our HDL level be?
Above 60, which is associated with a lower risk of heart disease.
A number less than 40 puts you in the “at risk” category for heart disease.
What it is
Triglycerides are a type of fat found in our blood. They come from vegetable oils and meat and dairy products. Our bodies also make them out of extra calories, if we have them. They are carried through our bloodstream by lipoproteins. If our cells don’t need them for energy, they are put into storage in our bodies as fat. So, no good.
Useful of not?
This number informs you if you are eating too many carbs, for one thing. If your value is substantially over the ideal range (<60 mg/dL), like 180 or higher, for example, it means you are overeating carbs and experiencing metabolic distortions because of it.
Very high numbers of triglycerides, in the range of 180 and higher, give you an idea of your insulin resistance, visceral fat, excess number of small LDL particles, and is suggestive of fatty liver disease. They will also block insulin, promoting weight gain (muffin tops and man boobs are a sign of high triglycerides). This is definitely associated with risk of heart disease.
What should triglyceride levels be?
Ideally, below 60 mg/dl.
If you are among the millions of people who get the conventional cholesterol panel annually, it’s good to know there is some useful information in it.
It’s also important to understand what is not so useful in these 4 numbers so that you do not needlessly take action to “treat” a number which is just fine as is.
Davis, Dr William. (2017). Undoctored. New York, NY: Rodale.
Moore, Jimmy. (2013). Cholesterol Clarity: What the HDL is Wrong with My Numbers? Victory Belt Publishing, Inc.