Thursday, February 23, 2012

The most important thing you probably don’t know about cholesterol

Following article by CHRIS KRESSER http://chriskresser.com/the-most-important-thing-you-probably-dont-know-about-cholesterol


  • The simplified view of cholesterol as “good” (HDL) or “bad” (LDL) has contributed to the continuing heart disease epidemic
  • Not all LDL cholesterol is created equal. Only small, dense LDL particles are associated with heart disease, whereas large, buoyant LDL are either benign or may protect against heart disease.
  • Replacing saturated fats with carbohydrates – which has been recommended by the American Heart Association for decades – reduces HDL and increases small, dense LDL, both of which are associated with increased risk of heart disease.
  • Dietary cholesterol has a negligible effect on total blood LDL cholesterol levels. However, eating eggs every day reduces small, dense LDL, which in turn reduces risk of heart disease.
  • The best way to lower small, dense LDL and protect yourself from heart disease is to eat fewer carbs (not fat and cholesterol), exercise and lose weight.

Not all cholesterol is created equal

By now most people have been exposed to the idea of “good” and “bad” cholesterol. It’s yet another deeply ingrained cultural belief, such as the one I wrote about last week, that has been relentlessly driven into our heads for several decades.

But once we’ve put on our Healthy Skeptic goggles, which I know all of you fair readers have, we no longer simply believe what we’re told by the medical establishment or mainstream media. Nor are we impressed or in any way swayed by the number of people that tell us something is true. After all, as Anatole France said, “Even if fifty million people say a foolish thing, it is still a foolish thing.”
Words to live by.

The oversimplified view of HDL cholesterol as “good” and LDL cholesterol as “bad” is not only incomplete, it has also directly contributed to the continuing heart disease epidemic worldwide.
But before we discover why, we first have to address another common misconception. LDL and HDL are not cholesterol. We refer to them as cholesterol, but they aren’t. LDL (low density lipoprotein) and HDL (high density lipoprotein) are proteins that transport cholesterol through the blood. Cholesterol, like all fats, doesn’t dissolve in water (or blood) so it must be transported through the blood by these lipoproteins. The names LDL and HDL refer to the different types of lipoproteins that transport cholesterol.

In addition to cholesterol, lipoproteins carry three fat molecules (polyunsaturated, monounsaturated, saturated – otherwise known as a triglyceride). Cholesterol is a waxy fat particle that almost every cell in the body synthesizes, which should give you some clue about its importance for physiological function.

You do not have a cholesterol level in your blood, because there is no cholesterol in the blood. When we speak of our “cholesterol levels”, what is actually being measured is the level of various lipoproteins (like LDL and HDL).

Which brings us back to the subject at hand. The consensus belief, as I’m sure you’re aware, is that LDL is “bad” cholesterol and HDL is “good” cholesterol. High levels of LDL put us at risk for heart disease, and low levels of LDL protect us from it. Likewise, low levels of HDL are a risk factor for heart disease, and high levels are protective.

It such a simple explanation, and it helps drug companies to sell more than $14 billion dollars worth of “bad” cholesterol-lowering medications to more than 24 million American each year.
The only problem (for people who actually take the drugs, rather than sell them, that is) is the idea that all LDL cholesterol is “bad” is simply not true.

In order for cholesterol-carrying lipoproteins to cause disease, they have to damage the wall of an artery. The smaller an LDL particle is, the more likely it is to do this. In fact, a 1988 study showed that small, dense LDL are three times more likely to cause heart disease than normal LDL.
On the other hand, large LDL are buoyant and easily move through the circulatory system without damaging the arteries.

Think of it this way. Small, dense LDL are like BBs. Large, buoyant LDL are like beach balls. If you throw a beach ball at a window, nothing happens. But if you shoot that window with a BB gun, it breaks.

Another problem with small LDL is that they are more susceptible to oxidation. Oxidized LDL, or oxLDL, is formed when the fats in LDL particles react with oxidation and break down.
Researchers have shown that the smaller and denser LDL gets, the more quickly it oxidizes when they subject it to oxidants in a test tube.
Why does this matter? oxLDL is a far greater risk factor for heart disease than normal LDL. A large prospective study by Meisinger et al. showed that participants with high oxLDL had more than four times the risk of a heart attack than patients with lower oxLDL.

I hope it’s clear by now that the notion of “good” and “bad” cholesterol is misleading and incomplete. Not all LDL cholesterol is the same. Large, buoyant LDL are benign or protect against heart disease, whereas small, dense LDL are a significant risk factor. If there is truly a “bad” cholesterol, it is small LDL. But calling all LDL “bad” is a dangerous mistake.

Low-fat, high-carb diets raise “bad” cholesterol and lower “good” cholesterol

Here’s where the story gets even more interesting. And tragic.
Researchers working in this area have defined what they call Pattern A and Pattern B. Pattern A is when small, dense LDL is low, large, buoyant LDL is high, and HDL is high. Pattern B is when small, dense LDL is high, HDL is low, and triglycerides are high. Pattern B is strongly associated with increased risk of heart disease, whereas Pattern A is not.

It is not saturated fat or cholesterol that increases the amount of small, dense LDL we have in our blood. It’s carbohydrate.
Dr. Ronald Krauss has shown that reducing saturated fat and increasing carbohydrate intake shifts Pattern A to Pattern B – and in the process significantly increases your risk of heart disease. Ironically, this is exactly what the American Heart Association and other similar organizations have been recommending for decades.
In Dr. Krauss’s study, participants who ate the most saturated fat had the largest LDL, and vice versa.
Krauss also tested the effect of his dietary intervention on HDL (so-called “good” cholesterol). Studies have found that the largest HDL particles, HDL2b, provide the greatest protective effect against heart disease.
Guess what? Compared to diets high in both total and saturated fat, low-fat, high-carbohydrate diets decreased HDL2b levels. In yet another blow to the American Heart Association’s recommendations, Berglund et al. showed that using their suggested low-fat diet reduced HDL2b in men and women of diverse racial backgrounds.
Here’s what the authors said about their results:
The results indicate that dietary changes suggested to be prudent for a large segment of the population will primarily affect [i.e., reduce] the concentrations of the most prominent antiatherogenic [anti-heart attack] HDL subpopulation.
Translation: following the advice of the American Heart Association is hazardous to your health.

Eating cholesterol reduces small LDL

The amount of cholesterol in the diet is only weakly correlated with blood cholesterol levels. A recent review of the scientific literature published in Current Opinion in Clinical Nutrition and Metabolic Care clearly indicates that egg consumption has no discernible impact on blood cholesterol levels in 70% of the population. In the other 30% of the population (termed “hyperresponders”), eggs do increase both circulating LDL and HDL cholesterol.

Why is this? Cholesterol is such an important substance that its production is tightly regulated by the body. When you eat more, the body produces less, and vice versa. This is why the amount of cholesterol you eat has little – if any – impact on the cholesterol levels in your blood.

Eating cholesterol is not only harmless, it’s beneficial. In fact, one of the best ways to lower small, dense LDL is to eat eggs every day! Yes, you read that correctly. University of Connecticut researchers recently found that people who ate three whole eggs a day for 12 weeks dropped their small-LDL levels by an average of 18 percent.

If you’re confused right now I certainly don’t blame you.
Let’s review what we’ve been told for more than 50 years:
  1. Eating saturated fat and cholesterol in the diet raises “bad” cholesterol in the blood and increases the risk of heart disease.
  2. Reducing intake or saturated fat and cholesterol protects us against heart disease.
Now, let’s examine what credible scientific research published in major peer-reviewed journals in the last decade tells us:
  1. Eating saturated fat and cholesterol reduces the type of cholesterol associated with heart disease.
  2. Replacing saturated fat and cholesterol with carbohydrates lowers “good” (HDL) cholesterol, raises triglyceride levels, and increases our risk of heart disease.
Dr. Krauss, the author of one of the studies I mentioned above, recently said in an interview published in Men’s Health, “Everybody I know in the field — everybody — recognized that a simple low-fat message was a mistake.”

In other words, the advice we’ve been given by medical “authorities” over the past half century on how to prevent heart disease is actually causing it.
I don’t know about you, but that makes me very angry. Heart disease is the #1 cause of death in the US. Almost 4 in 10 people who die each year die of heart disease. It directly affects over 80 million Americans each year, and indirectly affects millions more.
We spend almost half a trillion dollars treating heart disease each year. To put this in perspective, the United Nations has estimated that ending world hunger would cost just $195 billion.
Yet in spite of all this money spent, the best medical authorities can do is tell us the exact opposite of what we should be doing? And they continue to give us the wrong information even though researchers have known that it’s wrong for at least the past fifteen years?
Sometimes it seems like everything is backwards.

How to reduce small LDL

Eating fewer carbs is perhaps the best place to start. Reducing carbs has several cardio-protective effects. It reduces levels of small, dense LDL, reduces triglycerides, and increases HDL levels. A triple whammy.

Exercise and losing weight also reduce small, dense LDL. In fact, weight loss has been shown to reverse the evil Pattern B all by itself.

As we saw above, eating three eggs a day can reduce our small LDL by almost 20%. Interestingly, alcohol has also been shown to reduce small LDL by 20%.

In other words, if you want to reduce your risk of heart disease, do the opposite of the American Heart Association (and probably your doctor) tells you to do. Eat butter. Eat eggs. Eat traditional animal fats. Reduce your intake of carbs, vegetable oils and processed foods, and stay active and within a healthy weight range.

Testing your small LDL level

I’m not a fan of arbitrary testing. Our medical system is obsessed with testing. But where has testing has brought us with cholesterol and heart disease? Has it improved outcomes? On the contrary, we test for a number (total LDL) that tells us very little, and then medicate it downwards recklessly and expensively.
If you’re worried about your small LDL level, my advice would be to eat fewer carbohydrates, eat plenty of saturated fat and cholesterol (instead of vegetable oils), exercise, lose weight if you need to, and have a drink every now and then! Since this is the same advice I’d give you if you took a test that actually showed high levels of small LDL, I don’t see much value in doing the test.
However, if you need to see the test results to get motivated to make the changes I suggested above, by all means do the test. There are a few ways to go about it.

First, keep in mind that a regular cholesterol test at your doctor won’t tell you anything about your small LDL level. The standard tests measure your total cholesterol, LDL and HDL. But they don’t distinguish between the dangerous small LDL and benign or protective large LDL.

The fastest and cheapest, albeit most indirect, route is to test your blood sugar both before and then 60 minutes after a meal (this is called a “post-prandial” glucose test). The reason a post-prandial blood glucose test can be a rough indicator for small LDL is the same foods that trigger a rise in blood sugar also increase small LDL. Namely, carbohydrates.

Blood glucose monitors are readily available at places like Walgreens and cost about $10. You’ll also need lancets and test strips, which aren’t expensive either. If your post-prandial glucose is higher than 120 mg/dl, that may be suggestive of a higher than desired small LDL level. This test is not a perfect approximation of small LDL, but it’s the cheapest and and easiest way to get a sense of it.
If you want to get more specific, there are two tests I recommend for small LDL that use slightly different methodology:
  1. LDL-S3 GGE Test. Proteins from your blood are spread across a gel palette. As the molecules move from one end to the other, the gel becomes progressively denser. Large particles of LDL cholesterol can’t travel as far as the small, dense particles can, Dr. Ziajka says. After staining the gel, scientists determine the average size of your LDL cholesterol particles. Berkeley Heart Lab. About $15 with insurance.
  2. The VAP Test. Your sample is mixed into a solution designed to separate lipoproteins by density. Small, dense particles sink, and large, fluffy particles stay at the top. The liquid is stained and then analyzed to reveal 21 different lipoprotein subfractions, including dominant LDL size. The Vap Test. Direct cost is $40.
Chris Kresser

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