What is high cholesterol?
High cholesterol is a well-known risk factor for heart disease. Cholesterol itself is a waxy, fat-like substance that is primarily made by the liver, although some comes from the diet. It is an essential component of cell membranes and is used by the body to produce hormones and vitamin D.
Cholesterol is carried through the bloodstream attached to two different compounds called lipoproteins: low-density lipoproteins (LDL) and high-density lipoproteins (HDL). LDL is commonly known as the "bad" cholesterol because it transports cholesterol from the liver throughout the body, and potentially allows it to be deposited in artery walls. HDL, known as the "good cholesterol," picks up cholesterol from the blood and delivers it to cells that use it, or takes it back to the liver to be recycled or eliminated from the body.
Too much cholesterol in the blood builds up on artery walls causing hardening of the arteries (atherosclerosis). The buildup of cholesterol narrows arteries, slowing or blocking the flow of oxygen-carrying blood to the heart, which can manifest as chest pain. If blood flow to the heart is cut off because of clogged arteries, the result is damage to the heart muscle - a heart attack.
What are the symptoms of high cholesterol?
High cholesterol itself does not cause symptoms, so there are no outward signs that your levels are too high and thereby posing a risk to your heart.
What are the causes of high cholesterol?
The tendency toward high cholesterol appears to be genetic although diet also influences cholesterol levels. Other factors that can influence cholesterol levels include being overweight and being physically inactive. The older you get, the more likely your cholesterol levels are to rise. Before menopause, women tend to have lower cholesterol levels than men of the same age, but after menopause, women's LDL levels often increase.
There is considerable controversy over whether high cholesterol is in itself a cause of heart disease (the lipid hypothesis), or a symptom of an inflammatory condition that is the true cause of heart disease (the inflammation hypothesis). According to the latter theory, chronically high levels of inflammation creates small lesions on arterial walls; the body sends LDL to heal those lesions, but it ultimately accumulates and oxidizes, causing blockages. From this perspective, the best lifestyle approach to lower cardiovascular disease risk is to lower inflammation in the body rather than LDL levels.
The two theories are not mutually exclusive; they may both be true to some extent.
How is high cholesterol diagnosed?
Your cholesterol levels can be measured by a blood test done after you've fasted for nine to 12 hours. Results will reveal your total cholesterol level, your LDL and HDL levels as well as levels of triglycerides, the most common type of fat in the body. Some doctors also obtain tests for LDL particle size and number.
Desirable levels of total cholesterol are 200 mg per deciliter of blood or less; levels between 200 mg/dL and 239 mg/dL are considered borderline high; 240 mg/dL or higher is considered high cholesterol and raises your risk of heart disease to twice what it would be if your total cholesterol were 200 mg/dL or lower.
A desirable level of heart protective HDL cholesterol is 60 mg/dL or higher; levels below 40 mg/dL for men and less than 50 mg/dL for women increase the risk of heart disease. According to the American Heart Association, the mean level of HDL cholesterol for American adults age 20 and older is 54.3 mg/dL.
A desirable level of LDL ("bad") cholesterol is less than 100 mg/dL - the lower your LDL, the better in terms of heart disease risk. Levels between 139 and 150 mg/dL are borderline high and those between 160 to 189 mg/dL are considered high, while LDL levels above 190 mg/dL are classed as very high. According to the American Heart Association, the mean level of LDL cholesterol for American adults age 20 and older is 115.0 mg/dL.
Normal triglyceride levels are considered 150 mg/dL or lower; those from 150 to 199 mg/dL are considered borderline high while those from 200-499 mg/dL are considered high, and those above 500 mg/dL are deemed very high. The American Heart Association reports that the mean triglyceride level for American adults age 20 and older is 144.2 mg/dl.
What is the conventional treatment of high cholesterol?
Treatment of high cholesterol usually begins with lifestyle changes geared toward bringing levels down. These include losing weight if you're overweight, and changing your diet to emphasize vegetables and fruits, fish, particularly cold water fish such as wild Alaskan salmon, mackerel, herring and black cod that provide heart healthy omega-3 fatty acids. If lifestyle changes don't help or if you're unable to make the changes your doctor recommends, cholesterol-lowering drugs may be prescribed. These include statins, which effectively lower LDL cholesterol; bile acid sequestrants that may be prescribed along with statins to lower LDL; nicotinic acid to lower LDL cholesterol and triglycerides and raise HDL; drugs called fibrates that may be prescribed to lower cholesterol and may raise HDL; and a drug called Ezetimibe to lower LDL by blocking the absorption of cholesterol in the intestine.
What therapies does Dr. Weil recommend for high cholesterol?
Dr. Weil recommends making the following lifestyle and dietary changes in order to lower high cholesterol levels:
- Lose weight. Even a modest amount of weight loss can lower cholesterol levels.
- Reduce the amount of sugar and flour in your diet. Recent evidence indicates that added sugar - in the form of table sugar (sucrose) or high-fructose corn syrup - is probably a greater contributor to heart disease than is consumption of saturated fat. This suggests that the inflammatory hypothesis may in fact have more validity than the conventional lipid hypothesis, although the debate is far from settled. As a general rule, Dr. Weil advises against consuming foods with added sugars, particularly soft drinks and highly processed snack foods, which can cause rapid spikes and dips in blood sugar levels. The result can be overeating, obesity and heart disease.
- Avoid trans-fatty acids. These heart-damaging fats can reduce HDL ("good") cholesterol levels and raise levels of LDL ("bad") cholesterol. The tip-off that trans-fatty acids are present in foods is the listing of "partially hydrogenated oil" on a food's ingredient list. Trans-fats are found in many brands of margarine and in most heavily processed foods, as well as in snack foods such as chips, crackers and cookies, and in the oils used to cook fast-food French fries, doughnuts and movie popcorn.
- Exercise. Daily aerobic exercise can help increase HDL levels.
- Don't smoke. Smoking itself is a risk factor for heart disease. It can also significantly lower HDL cholesterol.
- Relax. Emotional stress may prompt the body to release fat into the bloodstream, raising cholesterol levels. Counter stress by practicing daily breathing exercises and other stress-reduction techniques such as yoga, meditation, guided imagery or tai chi.
Nutrition and Supplements
Dr. Weil recommends the following dietary changes that may help lower cholesterol levels.
- Eat some nuts every day. Choose almonds, walnuts and cashews, all of which contain heart-healthy monounsaturated fat.
- Substitute whole soy protein for animal protein. Soy protein such as tofu, tempeh, soy milk, whole soy beans and roasted soy nuts has been shown to lower cholesterol levels. Choose organic products where possible.
- Use fresh garlic regularly. Garlic has been shown to lower both cholesterol levels and blood pressure. Use one or two raw or lightly cooked cloves a day.
- Drink green tea daily. The antioxidants it contains help lower cholesterol and prevent the cholesterol in your blood from oxidizing.
- Eat plenty of soluble fiber. Beans and lentils, apples, citrus fruits, oats, barley, peas, carrots and ground flax seed are all good sources of soluble fiber, which has a powerful cholesterol-lowering effect.
- Limit refined carbohydrates. These include cookies, cakes, crackers, fluffy breads, chips and sodas, all of which can worsen cholesterol levels by lowering HDL and also increase triglyceride levels.
- Take coenzyme Q10 (CoQ10). This powerful antioxidant benefits heart health by protecting LDL cholesterol from oxidation and by re-energizing the mitochondria in the heart cells, which is where energy metabolism occurs. CoQ10 may also help lower blood pressure.
- Take fish oil. Fish oil contains an abundance of essential omega-3 fatty acids (omega-3s) that have been shown to lower triglyceride (blood fat) levels, minimize inflammation and clotting, and increase HDL ("good") cholesterol. Research indicates that omega-3s may help reduce the risk and symptoms of a variety of disorders influenced by inflammation, including heart attack and stroke. You can add omega-3s to your diet by eating more cold water fish such as wild Alaskan salmon, sardines, herring, mackerel and black cod. If that's not possible, Dr. Weil recommends taking two grams daily of a fish oil supplement that contains both essential omega-3 fatty acids, EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). When choosing a supplement, look for one derived from molecularly distilled fish oils - these are naturally high in both EPA and DHA and low in contaminants. Also choose a supplement brand that has been independently tested and guaranteed to be free of heavy metals such as mercury and lead, and other environmental toxins including polychlorinated biphenyls, also known as PCBs.
Updated, December 17, 2012