cholesterol-particlesHow did we arrive at the conclusion that LDL cholesterol is the villain in heart disease?

Well…once again we see the mistakes made by researchers that lead us to think of LDL as the culprit.

A little history…

It had to do with a machine used in the laboratory, called an analytical centrifuge that created evidence that ultimately mislead researchers and clouded the issue of cholesterol sub-particles.

Invented in 1949 and used until 2004, this device was used to spin blood plasma samples at 40,000 rpm to separate out the cholesterol fractions such as HDL and LDL.

However this spinning process cannot separate the particles with the precision required to identify all of the sub-fractions of cholesterol that are present in the blood. It may have been state of the art when it was first used, but still fell far short in the accuracy required to actually identify all the sub-fractions of cholesterol.

This started the characterization of cholesterol particles as either good or bad cholesterol, depending on the particle density. This was a gross oversimplification that stuck in the minds of the public.

For many years this simplified version of a person’s risk of heart disease based on their ratio of good and bad cholesterol stood as the cutting edge of cholesterol testing and heart disease prevention.

This was accompanied by the now debunked view that saturated fats caused heart disease because of their association with cholesterol. People avoided saturated fats out of a fear that was not founded in good science.

They also consumed statins, the most prescribed class of drugs on Earth due to the same fear of cholesterol and it’s supposed relationship to heart attacks.

Americans have consumed some 14 billion dollars in cholesterol lowering drugs, which some health experts have advocated be given to people of all ages including children allegedly to prevent heart disease.

John Abramson argues in his book Overdosed America that lowering LDL cholesterol has inadvertently become the main focus of preventative medical care in the United States.

Cutting edge thinking about LDL cholesterol

Yet a more recent breakthrough utilizing a new technology called ion mobility analysis has shaken the traditional concept of cholesterol’s role in heart disease to the core, and called the entire LDL cholesterol theory into question.

Ronald M. Krauss, of the Children’s Hospital Oakland Research Institute, is using ion mobility analysis to count cholesterol particles such as LDL and HDL down to the smallest sub particle types using principles of physics.

Even though it’s extremely expensive and not widely available, this technology has helped to rewrite the rules on how we think about cholesterol and heart disease.

Rather than continuing to believe that LDL cholesterol is the bad cholesterol here, we now know that there are four types of LDL particles that factor into the risk of heart disease.

Some LDL particles are benign and others more dangerous. Thus it makes no sense to continue to base diet and drug recommendations on an outdated theory when the science regarding cholesterol particle types is far more precise now.

We could be using drugs that target the wrong particles, and making dietary recommendations that are doing more harm than good at this point, all while dramatically escalating health care costs and actually making treatment less effective!

Low Density Lipoproteins

LDL comes in four sizes:

  • Large (big fluffy particles)
  • Medium
  • Small
  • Very Small

As the LDL particle size decreases the particles become more dense, (and more dangerous). This is because the large fluffy particles can’t lodge in your artery walls as plaque, while smaller dense LDLs CAN!

High fat diets tend to increase the large fluffy LDL particles, while low-fat high carbohydrate diets increase the smaller more dense particles.

From this you can see why the standard medical advice about how we should eat to avoid heart disease is seriously flawed! It was all based on an oversimplified and outmoded concept of the nature of cholesterol particles.

Typical cholesterol tests can’t differentiate between large and small LDL particles. There are also genetic, environmental, and lifestyle factors that affect LDL particle size.

Enter “Ion Mobility Analysis”

Using ion mobility analysis, Dr. Krauss and his colleagues determined that there are some 11 different particles. This was done using a sample of 4,600 healthy men and women volunteers.

Eight percent of the test subjects went on to develop heart disease, and using statistical algorithms the researchers developed a series of three very accurate predictors for who would go on to develop heart disease.

Here are the correlations that Dr. Kraus’s team found:

    1. High levels of small and medium LDL particles with low HDL (called atherogenic lipoprotein phenotype) Also known as pattern B
    2. Low HDL levels
    3. High total LDL cholesterol

So as it turns out LDL cholesterol and the risk of heart disease is a complex relationship that standard cholesterol tests are almost useless to predict.

The PLAC Test

There is one test however that can give you a better idea of what your risk is. You can read about it in my article called “The PLAC Test.” This is the latest test that really utilizes our new knowledge of LDL to make more accurate predictions about what your real risk for heart disease is.

Using this test you can make better choices about lifestyle and diet, because they are based upon a more complete understanding of the science of cholesterol particles.

Carotid ultrasound  is a non-surgical and painless test that is used to determine the amount of blockage of your carotid arteries. This is done by using ultrasound to create an image of the inside of the arteries.

carotid ultrasound
This allows the physician to assess the blood flow though your arteries and detect blockages caused by plaque buildup inside the carotid arteries that could put you at risk for a stroke.

This narrowing of the arteries is called “stenosis,” and is considered to be a big risk factor for strokes. There are two such arteries, one on either side of the neck. These arteries carry blood to the brain, and if this blood flow is interrupted, it can result in a stroke.

An ultrasound imaging of your carotid arteries is one of a number of tests that can be done to determine the extent of blockage or stenosis. There are several types of ultrasounds used. If you need this screening procedure, you should discuss with your doctor which version is appropriate for you.

Types of Carotid Ultrasound

There are two main types of tests that are used to image the carotid arteries.

  • Doppler ultrasound: This test actually creates images of the blow flow though the arteries.
  • Standard ultrasound: This test creates an image of the actual structure of the inside of the arteries.

Why are these tests performed?

The doctor may order a carotid ultrasound because he or she suspects there may be blockages or other types of damage to the artery wall that can prevent blood from getting to the brain, causing what is called an ischemic stroke, which is life threatening.

The problem may be a blood clot, or something called an artery dissection which is a damaging split in the artery wall. This condition can impede blood flow, or seriously weaken the artery wall, possibly leading to a stroke.

Another problem can be a narrowing of the artery because of plaque buildup involving bad cholesterol levels, which is called stenosis. This can be indicated by something called a bruit, which is a sound the doctor hears when using a stethoscope to externally examine your carotid arteries.

These abnormal sounds can indicate stenosis, so the doctor uses the carotid ultrasound to further determine just what is happening inside the arteries. There are other things that might cause the doctor to suspect artery disease such as:

  • High blood pressure
  • Advanced age
  • Diabetes
  • Bad cholesterol levels
  • Birth defects that affect the carotid arteries
  • Strokes
  • TIA’s (transient ischemic attacks)
  • Tumors (very rare)

Who would perform the test?

This test is performed by a medical professional called a radiological technician. This is a person trained in both the procedure and preparation for medical imaging scans. The test will sometimes be performed by a doctor called a radiologist. These physicians are experts on performing and analyzing the results of medical imaging scans.

The radiologist will analyze the carotid ultrasound results and give your doctor a diagnosis based on the imaging scans of your carotid arteries.

How carotid ultrasound works

The equipment operated by the radiological technician generates high frequency sound waves that are projected into your body by a hand-held instrument called a transducer. When these sound waves strike your tissue and are reflected back to the transducer, it creates an image of the shape and structure of the tissues being scanned.

The biggest advantage of carotid ultrasound is that it is non-invasive, meaning that no piercing or cutting of the skin surface is necessary, and that the scanning technology uses sound waves which are much safer than other imaging technologies that use ionizing radiation which can damage tissue.

How is this test performed?

This test is usually performed in a hospital or sometimes in an outpatient clinic. It takes about an hour and usually involves the following steps:

1) You dress in a standard patient exam gown sometimes called a Johnny. You can also wear your own clothing as long as the neck area is open and there is no jewelery around your neck.

2) You lie on the exam table, on your back, and the radiological technician applies a gel to your neck that helps the equipment make proper contact with your skin.

3) The tech will then place something called an ultrasound transducer on your skin. This is a hand held instrument that sends the sound waves into your body. As the tech moves it around on your neck it produces an image of your carotid artery and surrounding area. This process is completely painless.

4) When the ultrasound is finished the gel gets wiped off. You will have to wait a few minutes until the tech or radiologist makes sure that the scan is complete, and then they will send you home.

5) Your doctor will then contact you with the results of your scan and the diagnosis he has been given by the radiologist.

The carotid ultrasound is a very valuable test because it allows your doctor to see exactly how much plaque buildup there is in your carotid arteries and then create a treatment protocol based on this precise information. This test could warn you in time to prevent a stroke or other serious medical problem, which makes it one of the most effective tests for prevention there is.