Cholesterol is a so-called sterol that is responsible for transporting chemical messengers and proteins into cell membranes. Let’s do away with a widely held misconception right away: cholesterol is not a lipid or fat! In the body, it is a precursor to steroid hormones like (testosterone, estradiol, progesterone, corticoids) and bile acids. Cholesterol is thus a natural, vital component of human metabolism. Nonetheless, cholesterol values and triglyceride values are still commonly referred to as “serum lipids“.
Ninety percent of cholesterol is produced by the body itself. Approx. 500 mg of cholesterol are removed daily by the liver. To attain and maintain a healthy cholesterol level, it is necessary to support a delicate balance between cholesterol production, cholesterol intake through food, and cholesterol breakdown.
An elevated cholesterol level is not immediately noticeable. Generally, those affected do not recognize an elevated level until the end stage – when it has caused significant damage to blood vessels over a period of many years. Blood lipid levels can be measured through a blood analysis. In addition to the total cholesterol level, the lab report on the blood sample also includes triglyceride levels, as well as HDL (High Density Lipoprotein = “good cholesterol”) and LDL (Low Density Lipoprotein = “bad cholesterol”).
High Cholesterol Level – Causes and Consequences
Things that can cause elevated levels of cholesterol include:
- genetics (hypercholesterolemia runs in the family),
- diet (large amounts of saturated fatty acids),
- little exercise,
- obesity (Body-Mass-Index),
High cholesterol levels (synonymous with elevated serum lipids) is the result of an unhealthy diet rich in fats, but may also be influenced by hereditary factors. More than half of all adults aged 40 or more in western industrialized countries evidence an elevated cholesterol level.
High levels of serum lipids lead to build-up of fats in the interior walls of blood vessels. These build-ups, or plaques, can occur anywhere in the entire system of blood vessels. High blood pressure (hypertension) is also a common outcome of elevated cholesterol levels. The process is insidious and develops over several years. Depending on where in the body blood circulation is compromised, poor circulation in that area of the body leads to further problems:
- compromised circulation in the pelvic arteries can lead to erectile dysfunction,
- poor circulation in the inner ear may lead to tinnitus and vertigo,
- reduced circulation in the eyes may cause vision impairment and macular degeneration.
- Tissues that are cut off from blood circulation die quickly.
- The likelihood of blood clots (thromboses) increases sharply, which increases the likelihood of the complications they cause: pulmonary embolism and stroke.
An elevated cholesterol level can be significantly reduced with a concrete change in diet. Phytosterols, in particular, are known for their cholesterol-lowering effect. Taking the amino acids carnitine, arginine, and taurine, as well as vitamins and minerals may also help reduce cholesterol levels.
What is cholesterol?
Cholesterol is a sterol. Together with triglycerides, cholesterol is an important component in cell membranes. The body also requires cholesterol to synthesize several hormones. In the liver, cholesterol is used to produce bile acids which digest fats in the small intestine.
In short, cholesterol is a fundamentally required substance. However, too much cholesterol can lead to severe complications.
Serum lipid values: good cholesterol – bad cholesterol
There are several types of cholesterols: LDL-cholesterol (Low-Density Lipoprotein) and HDL-cholesterol (High-Density Lipoprotein). Sometimes, VLDL-cholesterol is also measured (Very Low Density Lipoprotein). These cholesterols are called “lipoprotein” as they refer to lipids bound to a protein. It is in this form that cholesterols flow in the blood and are transported within the body.
In Germany, serum lipids are indicated in “mg per dl blood” while in the Anglo-saxon part of the world they are indicated in “mmol” per liter. The conversion is simple: 1 mmol/l = 38.67 mg/dl
HDL cholesterol is the so-called “good” cholesterol. HDL cholesterol transports lipids from the blood vessels into the liver.
Values of “good cholesterol” (HDL) in the blood should be over 40 mg per dL blood.
LDL cholesterol and VLDL cholesterol are regarded as “bad cholesterol“. LDL cholesterol transports lipids from the liver into the blood. If they remain there (elevated LDL cholesterol level),the result is hardening of the arteries (atherosclerosis).
Blood levels of LDL cholesterol should be as low as possible. Generally, the goal is to remain below 100 mg per dL.
With a LDL cholesterol level above 100 mg per dL, the risk of cardiovascular disease increases. At levels above 159 mg per dL, the risk is high, and at levels above 190 mg per dL it is considered to be very high. For individuals who do not have additional risk factors for cardiovascular disease, a relatively high LDL cholesterol level of up to 160 mg per dL is still deemed acceptable.
Total cholesterol is the value of all types of cholesterol in the blood. It should be below 200 mg per dL blood. A value above 200 is called “hypercholesterolemia“.
At the age of 40, the average cholesterol level is approx. 230 mg per dL. It continues to increase with age. Elevated cholesterol levels are thus very prevalent.
Triglycerides are blood lipids and oils. In a lipid test, the value for triglycerides should be below 200 mg per dL, and preferably below 150 mg per dL (< 1.7 mmol per l). High triglyceride values increase the risk of blood clots and atherosclerosis.
The relationship between LDL and HDL is deemed even more important than the total cholesterol level. This ratio should be below four, preferably below three. This means that LDL should not exceed four times the amount of HDL in the blood.
The relationship between LDL and HDL is important
In addition to total cholesterol levels, the ratio of HDL cholesterol to LDL cholesterol is also important in determining the risk of heart infarcts and strokes. If the ratio of LDL to HDL is 3:1 or lower, the risk is low. Ideally, LDL cholesterol levels should be below 100 mg per dL blood and HDL cholesterol (the “good” cholesterol) approx. 40 mg per dL blood or higher.
Higher values of LDL cholesterol increase the risk of a heart infarct. If the ratio is 4:1 or higher (LDL to HDL) the risk is deemed high.
What are the consequences of elevated cholesterol levels?
An elevated cholesterol level results in damaging effects on arteries. The blood lipids stick to the interior walls (endothelium) of blood vessels. The build-up, or plaque, is initially spongy in consistency, but then hardens over the years.
Gradually, the flow of blood through the vessel is diminished, until it is eventually completely blocked. Additionally, metabolic processes within the vessels are impaired, with the result that they can no longer dilate sufficiently. High blood pressure (hypertension) is another long-term outcome of elevated cholesterol levels.
If other risk factors for atherosclerosis are also present in addition to elevated lipid levels, it is even more important to lower an elevated cholesterol level. Other risk factors for hardening of the arteries include:
- Excess weight/obesity
- Lack of exercise
- Elevated blood pressure
- Diabetes Mellitus
- High levels of homocysteine.
Atherosclerosis (damaged blood vessels) is the trigger for cardiovascular disease, hypertension, circulation disorders, and, in men, erectile dysfunction.
Amino acids and lipid metabolism / cholesterol levels
L-carnitine transports fatty acids into cells where they are converted to energy. Various studies with L-carnitine have shown that carnitine can help reduce cholesterol levels in participants. This was achieved by lowering the “bad” LDL cholesterol. The levels of the “good” cholesterol (HDL) remained constant among participants.
In another study, participants took 900 mg L-carnitine over a period of eight weeks. Study participants saw significant reductions in their cholesterol levels.2 Cholesterol levels also improved in patients with lipid metabolism disorders after they received 3,000 mg L-carnitine a day for six weeks. 3 Triglyceride levels in the blood were reduced and the ratio between total cholesterol and HDL cholesterol was improved.
Taurine stimulates bile flow. It also has some blood pressure-lowering properties. Elevated cholesterol levels lead to increased risk of blood clots (thromboses). Taurine has been observed to lessen the likelihood of platelet aggregation. 4
Arginine promotes flexibility in blood vessels and thereby helps the body regulate blood pressure naturally. In studies using arginine, it was also observed that the cholesterol level could be lowered by 10%. 5
Another study found that supplementation with L-arginine led to a reduction in the building of blood clots. 6
Vitamin C (ascorbic acid) plays a role in breaking down cholesterol into bile acids. A systematic review of 13 clinical trials found that taking vitamin C may significantly lower triglycerides and LDL cholesterol. The recommended dosage is 500 mg vitamin C or more. 7
Vitamin E inhibits the oxidation of LDL cholesterol and its antioxidative properties help protect cells. Taking vitamin E together with vitamin C is recommended. 8 The dose should be at least 36 mg vitamin E daily.
Niacin (Vitamin B3)
Niacin is especially popular in the US and its effects have been extensively researched. When looking for research on niacin in medical libraries, more than a thousand entries come up. Niacin has been attributed with slightly lowering LDL cholesterol levels and increasing HDL cholesterol.
In a recent study, extreme supplementation with niacin at a dose of 2,000 mg a day (120 times the recommended allowance), was not found to have any positive effects on cardiovascular disease. It may be best just to take a dose of up to 100 mg niacin a day (6 times the recommended allowance). Research results are not clear in this area.
Minerals / Trace Elements
Zinc is involved in many enzymatic processes and is a required element for regulating lipid metabolism.
Phytosterins and phytosterols are plant-based substances that have been shown to reduce cholesterol levels. Studies that prove their effects have also been confirmed by the EFSA (European Food Safety Authority). 9
Several renowned studies have reported that taking phytosterins may lower cholesterol levels between 10% and 15%.
Food consumption greatly influences cholesterol levels. With deliberate changes in diet, the cholesterol ingested through food can be significantly reduced. For example, 100 grams of butter contain 240 mg cholesterol, but 100 grams of margarine contain only 7 mg of cholesterol.
A general rule of thumb: foods rich in animal fats should be avoided. Fruits and vegetables are recommend because they do not contain any cholesterol. You can get the fats your body needs by eating unsaturated fats (omega 3s) like those found in fish (salmon), olive oil, sunflower oil, or thistle oil.
While eating fish is recommended in conditions of hypercholesterolemia, eating shellfish (crab, shrimp, lobster, etc.) is not. These items contain very high levels of cholesterol.
These foods are fundamentally healthy and recommended. They do not elevate cholesterol levels:
- Fruits and vegetables
- Especially pectins found in apples and saponins found in peas bind bile acids and thereby lower cholesterol.
- Bread, grains
- Ginger, garlic
- Olive oil, sunflower oil, thistle oil
- Poultry (without the skin which is rich in fat)
- Milk, yogurt
- Pasta from whole grains
- Nuts (walnuts, almonds, etc.)
Foods rich in animal fats especially to be avoided:
- Animal-based foods, particularly beef and pork rich in fat
- Egg yolk
- Egg pasta
- Some nuts (macadamia for example)
- Shellfish (shrimp, lobster, crab)
Frying food also adds cholesterol.
Exercise and lifestyle affect cholesterol levels
Plenty of exercise is important for blood vessel health and lowers LDL cholesterol levels.
Nicotine and alcohol are both contributors to an elevated cholesterol level and thereby directly or indirectly increase the risk of cardiovascular disease. Both should therefore be avoided.
Medications to lower cholesterol levels are by prescription only. They are complicated in their administration and have side effects.
Statins are a type of medication that may lower cholesterol. Statins inhibit an enzyme that is responsible for the production of LDL protein in the liver. They can lower cholesterol by up to 30% and are also referred to as “CSE inhibitors”.
Cholesterol absorption inhibitors are medications that adhere to the mucosa of the small intestine and there inhibit the absorption of cholesterol from food. Cholesterol absorption inhibitors are also sometimes combined with CSE inhibitors.
Fibrates reduce the production of triglycerides in the liver and therefore have positive effects on triglyceride levels in the blood. They may also help elevate HDL cholesterol levels. Fibrates reduce LDL cholesterol production between 5% and 20% and are thus not quite as effective as statins. Disadvantages of fibrates include that they increase the risk of gallbladder stones. Additionally, many patients report muscle pain and digestive problems as side effects of taking fibrates.
Elevated Homocysteine Levels
Elevated homocysteine values are similar to elevated blood lipid values in terms of the damage they can cause. If the body’s waste material homocysteine is not sufficiently broken down, it remains in high concentrations in the blood and builds up in the interior walls of blood vessels. The results are similar to those of an elevated cholesterol level: arterial deposits, atherosclerosis, circulation disorders with consequential organ damage, erectile dysfunction, and a high risk of cardiovascular disease. Read more about homocysteine levels here.
- Hopkins, J.; “Effect of carnitine on serum HDL-cholesterol: report of two cases”; Medical Journal (1982)Vol. 150, issue 2, pages. 51-54) ↩
- Maebashi M et al.; “Lipid lowering effect of carnitine in patients with type IV hyperliproteinemia”; Lancet (1978) 2: 805-807 ↩
- Pola, P. et al.; “Carnitine in the therapy of dyslipidemic patients”; Curr Ther Res (1980) 27: 763-764 ↩
- Chapman, R.A., Suleinan, M.S. & Earm, Y.E. (1993) “Taurine and the heart”, Cardiovascular Research, Volume 27, issue 3, (pp. 358-363) ↩
- Hursen, M., Regan, M.C., Kirk S.J. ;”Metabolic effects of arginine in a healthy elderly population”; Journal of Parenteral and Enteral Nutrition, 1995, Volume 19, pages 227-230 ↩
- Palloshi, A., Fragasso, G., Piatti, P., Monti, L.D., Setola, E., Valsecchi, G., Galuccio, E., Chierchia, S.L. & Margonato, A.; “Effect of Oral L-arginine on Blood Pressure and Symptoms and Endothelial Function in Patients With Systemic Hypertension, Positive Exercise Tests, and Normal Coronary Arteries”; The American Journal of Cardiology, (2004)Volume 93, pages 933-935 ↩
- McRae MP et al.; “Vitamin C supplementation lowers serum low-density lipoprotein cholesterol and triglycerides: a meta-analysis of 13 randomized controlled trials”; J Chiropract Med 2008; 7; 248-58 ↩
- Clarke, MW, et al.; “Vitamin E in human health and disease”; Crit Clin Lab Sci; 2008; 45 (5): 417-450 ↩
- http://www.efsa.europa.eu/en/efsajournal/doc/2203.pdf p.8 ↩