Americans are afraid of cholesterol. This is no surprise. For years we’ve been told, in essence, that cholesterol is a silent killer, building up in our arteries and causing coronary artery disease, heart attacks and strokes, all of which are pretty scary illnesses. We’ve gone to the doctor and seen great emphasis placed on our cholesterol “numbers”. When our numbers go up we feel concerned, when our numbers go down we feel relieved and safer, but are we really?
We’re right to be concerned about heart disease and stroke. Roughly 400,000 people die in the US each year from coronary artery disease, the clogging of the arteries that feed the heart muscle. This is considerably more than die from any other single disease! Another 135,000 or so people die from strokes, most of which are also caused by a clogging of the arteries which deliver nutrients to the brain. Even greater numbers of people experience the loss of function and impaired quality of life that come with these diseases.
The process underlying both of these conditions is atherosclerosis, the forming of “plaques” or bulges on the inside of blood vessels which leads to reduced blood flow through the affected arteries. When these plaques rupture, a clot is formed which can completely block the flow of blood through the effected vessel, leading to damage and death of the tissue served by that vessel. If that tissue is a portion of the heart or the brain, the consequences can be devastating or fatal.
The emphasis on cholesterol as a marker for atherosclerosis originally emerged from two findings. Plaques are formed partially from cholesterol, and early research done in the 1950‘s and 60‘s found an association between higher levels of cholesterol in the blood and heart attacks. As a result, lowering cholesterol, along with quitting smoking and weight loss, became the primary focus of reducing heart disease and heart attack risk. Since the introduction of cholesterol lowering drugs in 1987 (the statins), the emphasis on lowering cholesterol has only increased. (I imagine the fact that statins are the single most profitable class of medication in the history of pharmaceuticals may have something to do with it as well).
Now, it is important to understand:
In all the research that has been done over the years, dietary cholesterol and high levels of cholesterol in the blood have never been shown to cause heart disease or atherosclerosis.
That’s right, there is no evidence that high levels of cholesterol actually cause heart disease. The relationship between cholesterol and heart disease, heart attack and stroke has always been an “association”. An association simply means that two things often occur together, not that one of them causes the other. Seagulls and sunbathers, for instance, often occur together at the beach. This doesn’t necessarily mean that seagulls cause sunbathers, or that sunbathers cause seagulls.
In fact, as more and more research has been done over the years, the association between cholesterol and heart disease, and particularly heart attacks, appears to be getting weaker and weaker.
For example, it has been estimated that about 50% of people who have a heart attack have normal cholesterol levels. Furthermore, a study published several years ago found that almost 75% of heart attack patients had LDL levels within the recommended range, and about 45% had HDL levels also within the recommended range. (LDL is a sub-fraction of total cholesterol that is considered to be more harmful. HDL is a sub-fraction considered to have some protective effects). Another interesting study published this year found no association at all between total cholesterol or LDL cholesterol levels and incidence of heart attack.
If cholesterol isn’t causing heart disease, what is?
It has been fairly well established now that injury to the inner lining of blood vessels is the real cause of atherosclerosis and the diseases that result from it. This injury can come from physical forces, such as the increased pressure and turbulence that occurs in high blood pressure, or from chemical sources, such as free radicals (think of them as chemical sand paper), oxidized fats, compounds from inhaled tobacco smoke, high levels of sugar, insulin and certain other compounds.
Continued damage to the linings of the arteries leads to inflammation and an attempt by the body to protect and repair the damaged tissue. Cholesterol is laid down in the tissues as a part of the body’s attempted repair, but because the damage tends to be ongoing the body continues to deposit more and more cholesterol which leads to a growing bulge in the interior of the artery that reduces the flow of blood. If you continued to cut yourself over and over again in the exact same place you would eventually develop a really big scar!
So cholesterol is not the cause of atherosclerosis, but a part of the body’s attempt to heal. Now, there is a little bit of complexity here. Cholesterol may become damaged, or oxidized, by either improper cooking of the foods that contain it, or through contact with free radicals inside the body. If this occurs, then the oxidized cholesterol ends up contributing to arterial damage, but keep in mind that many other substances within the blood can also become oxidized and contribute to arterial damage, so cholesterol is not special in this respect.
Why is cholesterol often high in people with cardiovascular disease?
In my clinical experience, the single most common reason for high cholesterol levels is insulin resistance, a condition in which the body’s ability to remove sugar from the blood is impaired. This causes levels of sugar (glucose) within the blood to rise and in response the body produces more and more of the hormone insulin in an attempt to return blood sugar levels to normal.
In addition to removing sugar from the blood, insulin also sends a message to the liver to increase synthesis of cholesterol and its sub-fractions (HDL and LDL) in exactly the pattern we see with atherosclerosis or heart disease.
Now, here’s where it comes together. Both high levels of blood sugar and high levels of insulin damage the inner lining of the arteries leading to inflammation and plaque formation. So, while high levels of cholesterol do not cause atherosclerosis, they are often present as a product of the underlying dysfunctional process.
Cholesterol is essential for life!
Far from being a villain, cholesterol is actually essential for the function of every cell in your body. It forms a portion of the cell membrane and without adequate amounts cells cannot function properly. In addition, it is the building block for many important hormones, such as testosterone, DHEA, estrogen and progesterone. We believe that one of the reasons cholesterol levels tend to go up a little in women after menopause is that the body is trying to make more hormones.
A deficiency of any essential element in the body will lead to disturbances in health. This appears to be true for cholesterol as well. A number of studies have found an association between low levels of cholesterol and various psychiatric disorders such as depression, psychosis and suicide attempts. This is very concerning in light of the continued efforts being made to lower the recommended levels for total and LDL cholesterol and to increase the prescribing of statin medications such as Lipitor to achieve these levels.
There are other indications that excessively low levels of cholesterol are harmful as well. A European study involving over 11,000 people found that individuals with total cholesterol under 160 mg/dL, a number any cardiologist would be proud of, not only died of heart disease just as often as people with higher cholesterol levels, but their overall rate of death from all causes was greater than that of people with higher cholesterol levels, about 1.5 times greater! So for every 10 people with cholesterol values above 160 who died, 15 people with cholesterol values below 160 died! The most frequent cause of non-heart related death found in this study was cancer.
We’re zigging when we should be zagging!
Our current model for preventing and treating coronary artery disease is out of date and off base. Indeed, it continues to be the single largest cause of mortality in the United States. Every doctor practicing medicine knows that cholesterol doesn’t actually cause atherosclerosis or cardiovascular disease. Many of them are aware that arterial damage is actually the underlying cause. Scientists and executives in pharmaceutical companies certainly know that cholesterol doesn’t actually cause atherosclerosis. Nonetheless, the medical community continues to push for ever greater reductions in target levels for cholesterol and its various fractions as its primary treatment approach.
Now, the rate of deaths from cardiovascular disease have been going down fairly dramatically since the 1970’s, but mostly for reasons other than cholesterol related interventions. Medical and public education efforts have helped to reduce rates of smoking and high blood pressure, and emergency management of people with acute heart attacks has improved survival rates dramatically. In fact, a study published in the journal “Circulation” in 1994 estimated that only 9.5% of the reduction in deaths from cardiovascular disease could be attributed to reductions in cholesterol levels, and much of that reduction was attributed to changes in diet and lifestyle habits which likely improve other health parameters as well. According to the study only 0.7% of the reduction could be attributed to the use of statin medications.
So, what do we do instead?
In a word, we need to address the causes of arterial damage.
Perhaps the single most prevalent of these is insulin resistance which results in high blood sugar, high insulin and sometimes high blood pressure, all of which damage the inner lining of the arteries. Insulin resistance is currently at epidemic levels in the US and other developed countries. It is interesting to me that while acceptable values for cholesterol have gotten stricter and stricter over time, acceptable values for blood sugar have actually gotten more lax, and virtually no one (except our clinic and a few other naturopaths) test regularly for insulin levels.
How do you know if you have insulin resistance? Well, a complete evaluation is necessary to make a diagnosis, but here are some things to look for:
- You’ve had at least one fasting blood glucose test above 95
- You’ve had a hemoglobin A1c test above 5.4 (even though your doctor told you it was fine)
- The ratio between your LDL and HDL cholesterol is greater than 2.5 to 1, even with total cholesterol levels under 200
- You carry excess weight around your middle, but your arms, legs and behind are relatively thin
- You crave carbohydrates or have an excessive appetite (with other signs, not by itself)
- You have slightly but not dramatically elevated blood pressure
In addition to addressing insulin resistance, it is essential to normalize blood pressure of course, and if you smoke . . . well, you know . . . .
Beyond these, there are many things about modern life that can contribute to the development of atherosclerosis and its associated diseases: exposure to environmental toxins and heavy metals and deficiencies of certain nutrients, for example. Assessment of these risk factors is complex and requires a thorough workup. Many of these, however, fall into the category of “oxidative damage”. Eating a diet rich in natural antioxidants can help a lot and is probably more effective than eating poorly and taking antioxidant supplements. Not only do refined foods lack naturally occurring antioxidants but processing increases the levels of oxidative substances within foods. Antioxidant rich foods include: green leafy vegetables as well as all the orange, yellow and red colored vegetables, berries of all kinds and the great underdog of the food world, legumes (beans, peas and lentils).
The problem with statins:
Conventional medical therapies have relied more and more on drug interventions to lower cholesterol, particularly the statin class of medications which includes Lipitor, Zocor, Crestor and others. These medications do effectively lower total cholesterol and LDL cholesterol. Advocates will also point out that they do reduce the number of heart attacks. What’s curious is that there is no evidence that they actually prolong life. This means that if you are taking a statin you may be less likely to have a heart attack, but you will probably die just as soon as someone who isn’t taking one.
If statins are reducing the risk of cardiovascular disease how could this be? At this point we don’t know for sure, however, one possible explanation is that a few years after the introduction of statin medications in 1987, the rates of another kind of heart disease, congestive heart failure, started to rise dramatically. In the early 1980’s there were about 400,000 hospitalizations for congestive heart failure per year in the US. By 2004 there were over a million!
This makes some sense because statin medications deplete CoQ10, a naturally occurring compound that our bodies make and use for energy production. There is more CoQ10 used in the heart than anywhere else in the body because the heart requires a tremendous amount of energy to function. Heart failure is essentially a weakening of the pumping capacity of the heart, certainly something that could be brought on or worsened by inadequate energy in the heart muscle. To date, two studies have been done that look at changes in heart function before and after the start of statin therapy. Both studies showed changes in a large percentage of participants after initiation of statin therapy that were consistent with what is seen in early stages of congestive heart failure. It makes a person think, doesn’t it?
Additionally, one of the most common side effects from statins is muscle aches which occur because statin medications tend to damage muscle tissue. It’s possible that statins are also damaging heart muscle, although this hasn’t been established. Finally, based on other research that I discussed earlier in this article, lowering cholesterol levels excessively with statins may be contributing to increased mortality from non heart related causes by mechanisms that are not yet understood.
In addition to muscle pain and muscle damage, statins have other significant side effects as well, they are notoriously hard on the liver and kidneys (they can cause acute kidney failure) and they commonly cause cognitive impairment as well. The Department of Health in England estimates that up to 10% of patients on statins have significant side effects.
Putting things in perspective:
Coronary artery disease is the single greatest cause of mortality in the U.S. and we should be taking it seriously. Its cause, however, is not high cholesterol, and reducing cholesterol levels to ever lower numbers will not eradicate it. In fact, that policy very likely is and will continue to cause many other health problems such as increased rates of congestive heart failure.
The cause of coronary artery disease and other illnesses that result from atherosclerosis is really this: arterial damage. Except for the damage caused by high blood pressure, this damage comes from oxidative and inflammatory elements in the blood such as high blood sugar, insulin, homocysteine and environmental toxins.
To avoid atherosclerosis and all that comes with it we need to live in a way that normalizes these artery damaging elements.
We need to increase our intake of colorful vegetables, low sugar fruits and unrefined plant based foods. We need to decrease our waist lines and bring our blood sugar and insulin levels into a healthy range. Finally, we need to enjoy our lives and be part of a truly supportive social network. I could cite research on this, but hey, I’ve gone on long enough already.