The Cholesterol Myth

The Cholesterol Myth

What is cholesterol?

Cholesterol is a fat-like substance which is a major component in the cell membranes of animals. This means it is essential for the life of each cell in our bodies. For this reason the body does not just rely on us getting cholesterol from our diet but each cell makes its own cholesterol. It is also essential for making hormones in the body as well as vitamin D.

There has been much bad science around cholesterol, often promoted by pharmaceutical companies, for whom cholesterol lowering drugs are the biggest sellers worldwide, responsible for tens of billions of dollars in sales per year. They have a vested interest in keeping the status quo around cholesterol alive and well. While this article is certainly not the final word on cholesterol as much of the science is not settled yet, it should give you pause for thought when considering cholesterol treatment. So, what are some of the misunderstandings, myths and downright deceptions that are commonly found?

The Cholesterol Myths

  1. There is good and bad cholesterol.

There is no good or bad cholesterol. Because cholesterol is a fat-like substance it repels water. This means it can’t just float around in the blood stream but must be carried by another molecule called a lipoprotein. The two most common lipoproteins that many people have heard of are high-density lipoprotein (HDL) and low-density lipoprotein (LDL). These are like trucks that are able to carry the cholesterol from one part of the body to another. In general, HDL carries cholesterol to the liver where it can be recycled or excreted in bile, and LDL carries it to the body tissues. Too much LDL in the blood has generally been considered bad and more HDL has been considered good which is where the good and bad cholesterol misunderstanding came from.

       2. Cholesterol in your food can give you high cholesterol.

It is true that there is some effect from dietary cholesterol on blood cholesterol levels but this effect seems to be minor. The body makes about 3-4 times as much cholesterol as you eat. This is why in a review of 16 trials using a low cholesterol diet as an intervention for high cholesterol, the diet managed to lower blood cholesterol levels at on average about 3%.1

Studies of African tribes in Kenya and Somalia who eat very high amounts of animal fat and cholesterol through meat and dairy actually have lower cholesterol values than normal. Several other studies on more Western populations have shown little to no correlation between dietary cholesterol and blood levels.1 This is likely because the body is intelligent enough to vary the amount of cholesterol it produces depending on the dietary load.

      3. Your total cholesterol score is a useful measure of heart disease risk.

Although conventional wisdom is that levels of total cholesterol (TC) should be kept below 5mmol/l or 200mg/dl, a very wide range of values has been found in traditional indigenous cultures. Typical values range between 3.6 and 6.5 mmol/l (140-250mg/dl) in these cultures and they have very low rates of heart disease.40 These TC values will also vary depending on age (older generally higher) and sex (female generally higher).

Further evidence seems to suggest that those indigenous populations with a high burden of parasites had low cholesterol and those without parasites had higher cholesterol (over 5 mmol/l or 200mg/dl) independent of their type of diet. 41 The infections are taking up a portion of the cholesterol in the blood.

The French and the Swiss both have average cholesterol levels over 6 (230 mg/dl).  They also have the first and second lowest rates of heart disease among industrialized nations.  This is called the French (and Swiss) paradox. Russians have an average cholesterol level of 4.9 (190 mg/dl) – below that magic number of 5 (200 mg/dl).  Russians also have the highest rate of heart disease in Europe.44

       4. High cholesterol clogs the arteries and causes heart disease.

Uffe Ravnskov in his review of the literature on cholesterol and atherosclerosis has shown that there is no relationship between the two. In other words having high cholesterol is not the cause of atherosclerotic plaque (deposits in the walls of the arteries) formation.

In a 2009 study of over 130 000 people admitted to hospital with coronary artery disease, 75% had normal LDL cholesterol levels. 2 This flies completely in the face of what one would expect if high cholesterol was causing heart disease. Some observational studies have shown that people who have high cholesterol are more likely to have heart attacks than those that have normal cholesterol.8 However, this was true only for young men and doesn’t prove causation. Further studies have shown no relationship between cholesterol levels and future heart attacks.3

But cholesterol particles are found in the atherosclerotic plaques that line the artery walls. Doesn’t that prove that cholesterol causes heart disease? No, that shows an association. Just because you see a fireman at a fire doesn’t mean he is causing the fire. This metaphor might be apt because there is strong evidence that it is chronic inflammation in the body that is causing the heart disease.5,6 LDL cholesterol can be damaged by this inflammation and become oxidized and the oxidized cholesterol is then more likely to form plaques in the artery walls.6 It is more likely that a high cholesterol level may be a protective response by the body which produces a beneficial effect on the immune system.8

So the real question is how do we prevent this chronic inflammation in the body. First we need to know what causes the inflammation. The most common causes are:7

  1. Poor diet
  2. Stress
  3. Lack of exercise
  4. Smoking
  5. Poor sleep
  6. Infection

It is notable that all these factors can be controlled by natural means and don’t require medications. Diet is one of the most important of these. For a look at a low inflammation diet see this article.

        5. Low cholesterol is good

If high cholesterol is bad then low cholesterol must be good. On the contrary a low cholesterol level has been associated with a higher chance of dying from cancer, stroke, infections and ironically, heart disease.9-11,13 And in people over 60, high cholesterol has been shown to be inversely related to all-cause mortality.12 In layman’s terms this means people over 60 (when 90% of heart attacks occur) have much less chance of dying for any reason if their cholesterol is high!

         6. Cholesterol lowering drugs are necessary for everyone with high cholesterol

Based on the evidence above, the foundation for the billion dollar statin industry is looking shaky. Statins are medications that reduce the production of cholesterol in the liver. Statins do lower cholesterol and they do seem to reduce mortality due to heart attack and stroke. However, it has been shown that statins have this effect whether the person has high or low cholesterol to start with and regardless of whether the cholesterol levels are lowered a lot or a little.14 This suggests that the positive effect of statins is not related to cholesterol lowering but some other mechanism, most likely an anti-inflammatory effect.

Well, why not just take them anyway if they are helping? The truth is a little more complicated. It appears that positive clinical trials use statistical reporting that makes the results seem impressive. Results like 25-40% reduced risk of heart attack with treatment abound. But these are relative reductions. When looked at more closely the statistics show an absolute reduction in risk of 1-4%. In other words 90-100 people have to have the treatment to save one life, i.e. they fail at least 90% of people using them. 15

While statins may have a modest effect in reducing cardiovascular events, the only population group that has been shown to have any extension of lifespan with statins is men under 80 with pre-existing heart disease. Men under 80 with no heart disease, women of all ages and men over 80 receive no benefit to life extension.43

Now, even with these very modest effects it might still be worthwhile taking them if the adverse effects were few and minor. This may not be the case. There is evidence that adverse effects are underrecognised and underreported.16

The most common adverse effects are muscle pain, fatigue and weakness affecting up to 30% of patients, with severe muscle damage (rhabdomyolysis) a rare but disabling possibility. 42 Also concerning are studies showing increased risk of erectile dysfunction, memory loss, diabetes and cancer.16-20

At very least, if you would like to continue taking your statins, it is advisable to take supplementary Co-enzyme Q10 as this is depleted in the body by statins and can reduce side effects related to muscle problems.21,22

Cholesterol testing

You may have been for the typical finger prick test to look at your cholesterol levels which only measures your total cholesterol levels. As described above, this is a fairly useless test. A better measure of cholesterol levels is the standard lipid profile blood test. This generally gives you the results of your total cholesterol, HDL, LDL and triglycerides.

Total cholesterol: as discussed above, total cholesterol (TC) doesn’t give you much useful information unless combined with other lipid levels (see below).

Triglycerides: this is a measure of the amount of fat moving through your blood stream. It is has been shown in studies that a higher level of triglycerides is causally linked to an increased risk for heart disease. This means that a lower triglyceride level in the blood is better.23,24

So it makes sense that to lower your triglyceride (fat) level in the blood it would be necessary to eat a low fat diet. On the contrary, it has been shown in several studies that the culprit in raising triglyceride levels is a high carbohydrate diet. The effect is more pronounced with refined sugars (especially fructose) and is more pronounced in those who are already overweight.25-27

General recommendations are to keep triglycerides below 1.7mmol/l (150mg/dl)24 but it is better to aim for below 1.1mmol/l (100mg/dl).

HDL: it was originally thought that the higher your HDL level the better it was for your cardiovascular health. However, more recent research has cast doubt on this theory. Drugs designed to raise HDL levels have been detrimental for health of experimental subjects and very high levels of HDL have not been shown to be beneficial. That being said low HDL is definitely a marker for poor health and it is probably best to keep HDL in a band from moderate to high, equating to 1-2 mmol/l(40-75 mg/dl).28

LDL: because the general LDL measurement (also called LDL-C) has shown a poor correlation with heart disease risk as described in the myths above, research has focused on some other parts of the LDL puzzle. LDL-C refers to the amount of cholesterol contained in all the LDL particles. Research is now looking at the particles themselves and two main types or sizes have been distinguished: large fluffy (or buoyant) and small dense. The small dense LDL particles seem to be the problem ones whereas the large fluffy type are harmless.29

This goes a long way towards explaining the inconsistent results with LDL-C. A person may have a high LDL-C cholesterol level but their shape is large and fluffy so there is no risk to the cardiovascular system. But someone with a low LDL-C and the small dense type may be on a path to heart disease. Furthermore it has been shown that statin drugs do nothing to lower the small dense LDL levels and may in fact increase them while reducing the levels of the large fluffy type.30

Another subfraction of LDL being looked at is LDL-P: the number of particles of LDL. This has very little to do with the amount of cholesterol and has been much more strongly correlated with heart disease than LDL-C i.e. the higher the LDL-P the worse the outlook.31 This makes sense because if you have mostly small dense LDL particles then you will need more of them to carry the same amount of cholesterol as when you have mostly large, fluffy particles. As a result, you might also have a low LDL-C but still have a high LDL-P and this won’t be picked up by conventional testing.

Unfortunately, testing for these subfractions is much more expensive than the standard blood test but may be a good idea if you are concerned about high cholesterol levels or have a family history of heart disease or very high cholesterol. In South Africa the testing for the subfractions can be done here. Very often LDL-P testing is approximated by testing Apo-B which is a component of the LDL particle.

There are 5 factors which increase your chances of having a high LDL-P:32

  • Insulin resistance and metabolic syndrome
  • Poor thyroid function
  • Infection
  • Leaky gut
  • Genetics

The first 4 can all be helped by the correct diet. When it comes to genetics, familial hypercholesterolaemia (FH) is a disorder of cholesterol metabolism affecting about 1 in 500 people which results in very high total cholesterol levels greater than 8mmol/l (310 mg/dl).33 They have also been shown to have a higher than normal LDL-P. Genetic testing is necessary to confirm this though. People with FH should be followed by a medical practitioner due to their greater risk of heart complications.

Although the standard lipid profile blood test is not all that useful by itself some simple calculations can give better information:

Triglyceride to HDL ratio: this ratio seems to be a good predictor for heart disease.35 It is also a good approximation of the LDL-P levels in the blood. If the ratio is high this means a higher level of LDL-P – definitely a negative. Divide your triglyceride number by the HDL number for mg/dl (multiply the result by 2.3 if you are using mmol/l). The result should ideally be less than 1.3 but preferably less than 2.34,36 A ratio higher than 3.8 has also been shown to be associated with a preponderance of the small dense particle size – a no-no once again.37

Total cholesterol to HDL ratio: this ratio should be lower than 3.5.38 A high ratio has been correlated with insulin resistance (the step before diabetes).39

Remember with both of these ratios that they are do not say whether you have a disease or not. They are predictors of the risk that you might get the disease.

Because heart disease is highly correlated with inflammation it can also be worth testing for inflammation in the body with a blood test. The most commonly used test for this is C-reactive protein (CRP).

Conclusion

Cholesterol is a controversial subject. However, evidence is strong that the value of cholesterol testing has been overblown, especially when it comes to total cholesterol, and that cholesterol is of great importance to the human body and should not be unduly vilified.

Ultimately, decisions on whether to treat high cholesterol should be done in conjunction with your medical practitioner. However, very often medical practitioner knowledge on this subject is outdated and this article is written to keep you up to date with of pros and cons so you can make an informed decision.

References:

  1. http://www.ravnskov.nu/2015/12/27/myth-3/
  2. http://www.ahjonline.com/article/S0002-8703(08)00717-5/abstract
  3. https://www.ncbi.nlm.nih.gov/pubmed/1342254
  4. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC27435/
  5. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3644714/
  6. http://atvb.ahajournals.org/content/20/6/1536.full
  7. http://www.marksdailyapple.com/what-is-inflammation/
  8. http://qjmed.oxfordjournals.org/content/96/12/927.full?ijkey=172mwKXqzgmtE&keytype=ref
  9. https://www.ncbi.nlm.nih.gov/pubmed/21160131
  10. https://www.ncbi.nlm.nih.gov/pubmed/10870365
  11. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3247776/
  12. http://m.bmjopen.bmj.com/content/6/6/e010401.full.pdf
  13. http://www.ravnskov.nu/2015/12/27/myth-9/
  14. http://www.ravnskov.nu/2015/12/27/myth-6/
  15. https://www.ncbi.nlm.nih.gov/pubmed/25672965
  16. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2849981/
  17. http://qjmed.oxfordjournals.org/content/qjmed/early/2011/12/08/qjmed.hcr243.full.pdf?keytype=ref&ijkey=kZGZxqVjYWEOtoc
  18. http://www.greenmedinfo.com/article/statin-drugs-increase-risk-diabetes
  19. http://www.greenmedinfo.com/article/lipid-lowering-drugs-contribute-erectile-dysfunction
  20. http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0075467
  21. https://www.researchgate.net/publication/235785552_Coenzyme_Q10_and_selenium_in_statin-associated_myopathy_treatment
  22. http://www.sciencedirect.com/science/article/pii/S0014299913003026
  23. http://www.nature.com/ng/journal/v45/n11/full/ng.2795.html
  24. http://circ.ahajournals.org/content/123/20/2292
  25. http://jn.nutrition.org/content/131/10/2772S.full
  26. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2682989/
  27. https://www.ncbi.nlm.nih.gov/pubmed/11082210
  28. https://content.onlinejacc.org/article.aspx?articleID=2572335
  29. https://www.ncbi.nlm.nih.gov/pubmed/22989852
  30. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2929871/
  31. https://www.ncbi.nlm.nih.gov/pubmed/19657464
  32. https://chriskresser.com/what-causes-elevated-ldl-particle-number/
  33. http://emedicine.medscape.com/article/121298-overview?pa=qUODZlLvEH6H0ejvzXmJB67ckAmLKx40P7d2Sccw0FZap6xY6p2K9MDB33p7cHXqIYBuKbLtyjjBgaaJJ4Mv0ZwfqwaG3lIao9g53Y4UE8Q%3D
  34. http://care.diabetesjournals.org/content/diacare/23/11/1679.full.pdf
  35. https://www.ncbi.nlm.nih.gov/pubmed/19091534
  36. http://www.docsopinion.com/2014/07/17/triglyceride-hdl-ratio/
  37. http://www.sciencedirect.com/science/article/pii/S000291490400517X
  38. http://ispub.com/IJAM/6/2/9074
  39. https://www.researchgate.net/publication/13657675_Individuals_with_high_total_cholesterolHDL_cholesterol_ratios_are_insulin_resistant
  40. https://chriskresser.com/episode-16-chris-masterjohn-on-cholesterol-heart-disease-part-2/
  41. http://perfecthealthdiet.com/2011/07/serum-cholesterol-among-hunter-gatherers-conclusion/
  42. http://jama.jamanetwork.com/article.aspx?articleid=2511043
  43. https://chriskresser.com/the-diet-heart-myth-statins-dont-save-lives-in-people-without-heart-disease/
  44. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1768013/

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