Causes of High Cholesterol
High cholesterol can be caused by a variety of things. Many of the causes can be altered directly simply by lifestyle changes and therefore are considered controllable causes of high cholesterol. These are sometimes referred to as major risk factors.
Genetics. One of the main causes of high cholesterol is hereditary. Your genes may be influencing how your liver synthesizes, uses and disposes of LDL. Defects in the receptors on lipoproteins can also affect your cholesterol levels. Furthermore, there are specific forms of inherited high cholesterol called familial dyslipidemias. They include:
- Hyperchylomicronemia (Type I) is primarily caused by a deficiency of lipoprotein lipase. You end up having an increase in chylomicron levels.
- Hypercholesterolemia (Type IIa) is due decreased LDL receptors in the extrahepatic tissues. LDL levels are increased in the blood.
- Combined hyperlipidemia (Type IIb) is caused by hepatic overproduction of VLDL. Both LDL and VLDL levels are increased in the blood.
- Dysbetalipoproteinemia (Type III) is due to an altered apolipoprotein E. VLDL and IDL levels are high in the blood.
- Hypertriglyceridemia (Type IV) is caused by hepatic overproduction of VLDL. There is more VLDL in the bloodstream.
- Mixed hypertriglyceridemia (Type V) is due to the overproduction and decreased clearance of VLDL and chylomicrons. As expected, there are more VLDL and chylomicrons in the blood.
Type IIb and IV are the two most common types of familial dyslipidemias and are closely linked to vascular diseases associated with diabetics, the obese and the pregnant. Note: The above are specific forms of high cholesterol influenced by your genes. It is important to remember that you can have high cholesterol from other genetic factors not mentioned above.
Age. As people age, cholesterol levels rise and the associated risk for vascular disease rises along with it. Before age 50-55, women tend to have lower cholesterol levels than their male counterparts of equal age. The finding reverses itself around age 55 when women are shown to have higher cholesterol levels. Both genders are at increased risk after about age 50 and risk levels continue to rise until about age 65, when there is a leveling off.
Gender. Since cholesterol is a precursor to many of the body’s natural hormones, it should be no surprise that cholesterol levels are affected by menopause. Before menopause, women have lower cholesterol levels (specifically LDL) than men. After menopause, women quickly catch up to the cholesterol levels in men and exceed them around age 50-55.
Pathology. Obviously, diseases of key systems in the body can directly affect your blood cholesterol levels. For example, thyroid related problems may cause you to have a decreased metabolism, affecting your body’s ability to deal with cholesterol. Another example is liver disease. Since the liver produces and synthesizes cholesterol and associated lipoproteins, liver damage can easily affect total blood cholesterol. Drugs that cause any related pathology may also play a prominent role. All of these possibilities should be considered when trying to ascertain the cause of elevated blood cholesterol.
Diet. Diet is the first controllable risk factor on this list and one of the major causes of high cholesterol. A healthy, well-balanced diet that is high in fiber and low in saturated fat is always sound advice. Since cholesterol can be directly derived from dietary animal and dairy products, care must be taken to examine these foods for people with high cholesterol.
Exercise and weight loss. Excess body fat affects many systems in your body, including cholesterol levels. Overweight people have a harder time controlling rising LDL levels and to make matters worse, HDL levels drop. Exercise becomes an effective tool in fighting high cholesterol since it can help keep LDL levels from rising (even decreasing your TGs) while actively helping your vasculature by elevating your HDL levels.
Alcohol. A controversial topic and often a scapegoat used by alcoholics, moderate alcohol use can actually elevate HDL levels in the blood, thereby increasing the protective factor against heart disease. The key here is moderate use, which is about 1-2 drinks a day (about 120 ml of table wine or 25 ml of hard spirit). More than that can actually damage the liver (cirrhosis) and elevate cholesterol in the blood.
Stress. Studies are being done to link the amount of mental stress, consumption of saturated fats and daily lifestyle to the level of cholesterol in the blood.