When you think of LDL, you probably automatically identify it as the bad stuff that causes heart attacks. When you have your blood lipids checked, LDL is probably one of the main items you're interested in seeing.
But did you know that when you go for a blood test, the lab estimates this number?
First, total cholesterol, HDL and triglycerides are measured. They are then used to calculate LDL using what is known in the biz as the Friedewald Formula.
It's not at all difficult to do for yourself. Just plug in your numbers, and you can recalculate your LDL. I decided to use my latest bloodwork, and I'm happy to report that my numbers agree completely.
LDL = Total - HDL - Tri/2.2
In my case: 6.63 - 2.21 - (0.45/2.2) = 6.63 - 2.21 - 0.205 = 4.22(This shows that my LDL cholesterol is off the scale high. The upper limit of the reference range is 3.40. But more about that in a bit.)
If you're an American, you need to use a slightly different formula, since your lipids are measured in mg/dL:
LDL = Total - HDL - Tri/5For people with very high triglycerides, it has been known for a long time that this formula isn't very accurate. To get at the right number, the lab would have to measure LDL dirctly. This is expensive, and so it's not normally done.
More recently, high fat, low carb diets became more popular, and more and more people started showing up with extremely low triglycerides. Now there is a growing awareness that this formula also gets these people's LDL counts wrong. We'll never know how many family physicians took one look at their low-carb patients' seemingly high LDL and unnecessarily convinced them to go back to their previous low-fat diet. But I digress...
Essentially this is because LDL cholesterol consists of both tiny little bad particles (known as VLDL or very low density lipoproteins) and large fluffy ones that are too big to slip through cell membranes and do any harm. It's the little ones that sneak about causing trouble, but when you have very low triglycerides, there are very few of them around.
The Friedewald formula pretty much assumes all the LDL particles are of a similar size, and because this is very much not the case when the concentration of triglycerides is either very high or very low, the formulas above give bogus numbers.
It's like using a formula for a linear graph when in fact you should be plotting a curvilinear chart.
Since we already know that HDL and triglycerides are excellent predictors of coronary heart disease risk, my lay-brain finds it hard to understand why we even need to go on to determine an LDL count.
If you're wondering the same thing, you might also enjoy this interview with Gary Taubes, where he explains how the experts manipulated the relative importance of LDL cholesterol back in the 60's and 70's.
Maybe it's just that the entire western world is indoctrinated into believing LDL is more important than it really is, or perhps it's a fun way to occupy legions of scientists, doctors, labs, and of course, the drugmakers.
Be that as it may, there are alternative formulas designed especially for conspiracy-minded people with time on their hands, and for those who have low triglycerides, like I do.
By now you must really be wondering about the title to this post. Of course it's tongue in cheek. But there is an Iranian connection. You see, you can read a 2008 study reported in the Archives of Iranian Medicine. The researchers remeasured their test subjects' LDL directly and then performed regression analysis to determine that a more appropriate formula should be:
LDL (mg/dL) = TC/1.19 + Tri/1.9 – HDL/1.1 – 38You will see this is in the American mg/dL, so if you are a Canadian and your numbers are in mmol/L, you'll have to convert them first. Luckily this is not hard to do with this handy online tool.
You must be wondering about my apparently dangerously high LDL of 4.22.
The Iranian formula recalculates my LDL at a more respectable 3.1 mmol/L, which means I'm back into the reference range of 2.00 to 3.40.
Doubtless Big Pharma would be delighted to discredit this foreign paper. Anything to keep sales of cholesterol lowering drugs on the linear trajectory that keeps them wealthy.
Given the political tensions in the Middle East, there must be many Americans, blissfully unaware of Persia's historical role in the development of Medicine, who would fall for this.
But let's say it like it is: current LDL measurements fail miserably to tell the truth. Given the sophisticated tools available in our medical system, I find it hard to come up with a logical explanation for the nutritional experts' failure to fix this.
It seriously makes me wonder about the extent of deception, collusion and suppression of the truth in this industry.
It also makes me wonder how many people have unnecessarily been prescribed with statins, some with significant side-effects, just because LDL is arithmetically derived by means of an inadequate formula.