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Hypercholesterolemia
Cholesterol is a soft waxy substance that is a natural component of the fats in the bloodstream and in all the cells of the body. While cholesterol is an essential part of a healthy body, high levels of cholesterol in the blood (known as hypercholesterolemia) increase a person's risk for cardiovascular disease, which can lead to stroke or heart attack. When there is too much cholesterol circulating in the blood, it can create sticky deposits (called plaque) along the artery walls. Plaque can eventually obstruct or even block the flow of blood to the brain, heart, and other organs. A recent report indicates that more and more Americans have high cholesterol—the condition is most common among those living in Western cultures. While heredity may be a factor for some people, increasingly sedentary lifestyles combined with diets high in saturated fats appear to be the main culprits. The normal range for total blood cholesterol is between 140 and 200 mg per decilitre (mg/dL) of blood. Levels between 200 and 240 mg/dL indicate moderate risk, and levels surpassing 240 mg/dL indicate high risk. While total cholesterol level is important, it does not tell the whole story. There are two main types of cholesterol: low density lipoproteins (LDL) and high density lipoproteins (HDL). HDL is generally considered to be "good" cholesterol, while LDL is considered "bad." Triglycerides are a third type of fatty material found in the blood. While their role in heart disease is not entirely clear, it appears that as triglyceride levels rise, levels of "good" cholesterol fall. It is the complex interaction of these three types of lipids that is thrown off when a person has hypercholesterolemia. High cholesterol is characterized by elevated levels of LDL cholesterol, normal or low levels of HDL cholesterol, and normal or elevated levels of triglycerides. Signs and Symptoms In its preliminary stages, high cholesterol generally occurs without any symptoms. For this reason, screening through routine blood tests is crucial for early detection. In its advanced state, however, high cholesterol may result in any of the following: Causes In some cases, abnormally high cholesterol may be related to an inherited disorder. Certain genetic causes of abnormal cholesterol and triglycerides, known as hereditary hyperlipidemias, are often very difficult to treat. High cholesterol or triglycerides can also be associated with other diseases a person may have, such as diabetes. In most cases, however, elevated cholesterol levels are associated with an overly fatty diet coupled with an inactive lifestyle. It is also more common in those who are obese, a condition that has now reached epidemic proportions in the United States, affecting as much as half of the adult population. Causes of high total and LDL cholesterol levels include: Causes of low HDL cholesterol include: Causes of high triglyceride levels include: Risk Factors There are certain factors that put a person at increased risk of having high cholesterol. While some factors cannot be altered by changes in lifestyle, many can be changed. The most important risk factors for high cholesterol are: Diagnosis Since most people have few if any symptoms of hypercholesterolemia (another term for high cholesterol), blood screening is very important. An initial blood test is done to check a "random" measurement of total and HDL cholesterols, meaning that the test is performed at any time during the day, regardless of what has been eaten. Those with abnormal levels (total cholesterol more than 200 mg/dL or HDL less than 40 mg/dL), will go on to have a test called fasting lipid profile (in which the person being tested refrains from eating for 8 to 12 hours, usually overnight, prior to the test). The fasting test will indicate whether or not total cholesterol levels fall within the normal range (between 140 and 200 mg/dL), are moderately high (between 200 and 240 mg/dL), or if they are in the very high range (240 mg/dL or greater). This blood test also reveals the levels of LDL, HDL, and triglycerides. According to guidelines released by the National Cholesterol Education Program (NCEP), the optimal level for LDL cholesterol depends on whether you have heart disease or not and whether there are other risk factors present for heart disease (such as diabetes and high blood pressure). The optimal level for HDL for all people (healthy or otherwise) is a measurement higher than 60 mg/dL; low levels are 40 mg/dL and below. Adults with normal total and HDL cholesterol levels should have their cholesterol checked every 5 years. Those being treated for hypercholesterolemia should have their cholesterol levels measured every 2 to 6 months and have liver function tests as well if they are on cholesterol-lowering medication. Preventive Care Changing eating habits is key in preventing high cholesterol. Other lifestyle changes that can reduce the risk of developing high cholesterol and cardiovascular disease include maintaining a normal weight and increasing physical activity. Diet The best ways to lower cholesterol through diet include the following: There are a number of diets designed to keep cholesterol levels in check including the American Heart Association (AHA) diet, the Mediterranean diet, and the Ornish diet. While these three diets vary in some ways, they all emphasize whole grains and include fiber, fresh fruits and vegetables, lean protein, particularly soy and fish, and avoidance of saturated fats and trans fatty acids. These diets are outlined below. The AHA Step I Diet is considered appropriate for the general population, including those who have normal cholesterol levels and want to prevent the development of high cholesterol. This diet calls for up to 55% of daily calories from carbohydrates, 15% from protein, and no more than 30% from fat. The diet also outlines quite specific of types of fat and the proportions to include: This diet also specifies the level of calories that helps people achieve and maintain a healthy weight, and it is ideal for those who currently include a lot of fat in their diets and have not previously attempted to lower their cholesterol levels through dietary changes. The AHA Step II Diet is designed for patients who require greater LDL lowering, and includes the Step I guidelines (above) with two modifications: The Mediterranean Diet is comprised of whole grains, fresh fruits and vegetables, fish, olive oil, garlic, and moderate, daily consumption of red wine. Although this diet is not low in fat, it is high in monounsaturated fatty acids and has been shown to increase HDL cholesterol levels and to inhibit the process whereby LDL cholesterol adheres to artery walls. One large, well-designed study found that people who had had at least one heart attack were between 50% and 70% less likely to suffer a another heart attack if they followed the Mediterranean diet. This diet puts a great emphasis on bread, root and green vegetables, and the daily consumption of fruit, fish, and poultry. Only olive and rapeseed (canola) oils are used in this eating plan and margarine (with alpha-linolenic acid) is used instead of butter. Eating beef and lamb is discouraged. This diet is naturally rich in fiber, antioxidants, and omega-3 fatty acids. It contains the same amount of protein as the AHA diet, but the source of protein is primarily fish. The Mediterranean diet has less carbohydrates than the AHA or Ornish diets, but places the same emphasis on consuming fruits, vegetables, nuts, legumes, and beans. The Ornish Diet is a completely vegetarian diet that has been shown to dramatically reduce cholesterol levels and to actually reverse the risk of heart disease. No oils or animal products are allowed in the Ornish diet, except nonfat dairy products and egg whites. In this diet, total fat is limited to 10% of daily calories, saturated fats are significantly limited, and carbohydrates generally make up 75% of calories. Complex carbohydrates from whole grains and other high-fiber foods and from fresh fruits and vegetables are emphasized. Weight Reduction Being overweight increases risk of high cholesterol and heart disease. Even small degrees of weight loss can make nutritional changes more effective in lowering LDL—a 5 to 10 pound weight loss can double the LDL reduction achieved by dietary adjustment alone. Weight loss is often accompanied by lowered triglycerides and increased HDL levels as well. The goal for weight loss should be a realistic one, rather than a rapid or dramatic loss. Very low calorie diets (500 to 800 calories) can be dangerous and are not recommended. A reasonable caloric restriction is considered a reduction of 250 to 500 calories per day in the usual diet aimed at achieving a gradual, weekly weight loss of one-half to one pound. Physical Activity Regular physical activity by itself both reduces the risk of death from heart disease and enhances the effects of diet on LDL cholesterol levels. In a study of 377 people who were divided into four groups (aerobic exercise, the AHA Step II diet, the Step II diet plus exercise, or no intervention), those who only made dietary changes did not show reduced LDL while the group on the Step II diet plus exercise had a significant reduction in LDL cholesterol. Moderate exercise three to five times per week (the equivalent of walking 7 to 14 miles per week) can help promote weight loss in overweight individuals, reduce LDL and triglyceride levels, and produce favorable levels of HDL. Exercise may also lower blood pressure. For these reasons, everyone with risk factors for heart disease should consider starting a program of regular, aerobic physical activity, individualized to suit physical fitness level, heart health, and exercise preferences. Treatment Approach The main goal of treatment is to reduce the risk of cardiovascular diseases, such as heart disease and stroke, by lowering blood cholesterol levels. Studies have shown that for every 1% reduction in cholesterol levels there is a 2% reduction in the rate of heart disease. People who benefit most from lowering their cholesterol are those who already have heart disease or who have multiple risk factors for the disease. In addition to lifestyle changes, specific cholesterol-lowering medications are often prescribed. Changes in lifestyle are the most effective means of both preventing and, in less severe cases, treating elevated LDL cholesterol levels. The cornerstone of this treatment strategy is dietary modification and exercise. In addition to little fat and cholesterol, lean protein (such as soy and fish), and lots of fruits and vegetables, diets should include: In addition, herbs and supplements may help lower cholesterol levels. The most promising include: Lifestyle The following changes in life habits have been shown to both prevent high cholesterol and to lower high levels of cholesterol and triglyceride: Medications According to the National Cholesterol Education Program (NCEP) guidelines, healthcare practitioners should prescribe cholesterol-lowering medication when: The following are commonly prescribed medications for high cholesterol: Nutrition and Dietary Supplements There is considerable evidence that dietary antioxidants, particularly vitamin E, as well as folic acid, fiber, and soy can help to prevent the development of heart disease. Substances that have shown promise in lowering cholesterol specifically or that have demonstrated benefit in preventing heart disease in people with high cholesterol are discussed below. Fiber and Fiber Sources The American Heart Association (AHA) recommends increased intake of dietary fiber in the form of whole grains, vegetables, fruits, legumes, and nuts because they have been shown to do the following: Soluble fibers such as those in psyllium husk, guar gum, and oat bran have a cholesterol-lowering effect when added to a low-fat, cholesterol-lowering diet. Studies have shown psyllium, in particular, to be quite effective in lowering total as well as LDL cholesterol levels. Oat bran (3 g per day) has also been shown to lower total cholesterol. Soy Many studies have shown that replacing some animal protein with soy protein in the diet results in lower blood cholesterol levels, especially when soy is consumed as part of a general low-fat diet. One study has shown that as little as 20 g of soy protein per day is effective in reducing total cholesterol, but that 40 to 50 g shows faster effects (in 3 weeks instead of 6). This evidence suggests that soy protein should be included in a healthy diet. In fact, since October of 1999, the FDA has allowed the labels of foods containing 6.25 g or more of soy protein to carry the claim that these foods reduce the risk of heart disease. Moreover, the AHA recommends that people with elevated total and LDL cholesterol add soy to their daily diet. Ethanol-washed soy preparations should be avoided because this procedure causes the soy to lose its isoflavones (the substances likely responsible for its cholesterol-lowering effects) in the process. Omega-3 fatty Acids EPA and DHA Numerous studies have reported the benefits of consuming fish oils, rich in the omega-3 fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), at doses ranging from 850 mg to 4 g per day for those with heart disease. Supplementation with DHA, for example, has been shown to reduce triglycerides and LDL levels and raise HDL levels. Alpha-Linolenic Acid Walnuts are one of the best sources of the omega-3 fatty acid alpha-linolenic acid. Replacing a major portion (35%) of the monounsaturated fat in the Mediterranean diet with walnuts appears to significantly improve cholesterol and triglyceride levels in people with high cholesterol. Almonds, although not as well studied as walnuts, appear to have similar effects when used as a substitute for a portion of monounsaturated fats in low-fat diets. Vitamin E A number of studies conducted over the last 10 years have reported beneficial results from the use of vitamin E supplements for the treatment and prevention of heart disease including for those with elevated cholesterol levels. Vitamin C Preliminary evidence suggests that vitamin C (3 glasses of orange juice per day or up to 3 g per day as a supplement) may help decrease total and LDL cholesterol and triglycerides, and increase HDL levels. Coenzyme Q10 (CoQ10) Coenzyme Q10 (CoQ10), also known as ubiquinone, is an antioxidant that is essential for energy production. Levels of CoQ10 have been found to be lower in people with high cholesterol when they were compared to healthy individuals of the same age. Furthermore, when person with high cholesterol take statin drugs, CoQ10 levels appear to decline in direct proportion to the level of decrease in cholesterol. This is particularly important to bear this in mind when statin drugs are used for long periods of time. Taking CoQ10 supplements, however, can correct the deficiency caused by statin medications without affecting the medication's positive effects on cholesterol levels. Folic Acid (Vitamin B9) High blood levels of homocysteine (an amino acid produced by the body) have been shown to increase the risk of heart attacks. Evidence suggests that high homocysteine levels are also related to low folate levels. This means that an adequate supply of folate and other B vitamins may be important, particularly for those with heart disease. Plant Sterols Plant sterols (fats present in fruits, vegetables, seeds, and nuts) appear to interfere with the absorption of cholesterol, thereby lowering the level of cholesterol in the blood. A daily intake of 1.6 g of margarine containing plant sterols has been shown to reduce total and LDL cholesterol, with larger intakes not necessarily providing any additional benefit. Questions have been raised, however, regarding the possibility that plant sterols interfere with the absorption of certain antioxidants such as alpha- and beta-carotenes, alpha-tocopherol, and lycopene. While the significance of this is still unclear, it warrants further investigation, and these micronutrients must be carefully monitored in the blood of those using plant sterols. L-Carnitine L-carnitine is produced in the liver and kidneys from the amino acids lysine and methionine. It is stored in skeletal muscles and the heart and may be beneficial in treating conditions such as chest pain, heart attack, heart failure, diabetes, and abnormal cholesterol. In several human studies, supplementation with 2 to 3 g per day of L-carnitine led to a significant reduction in total cholesterol and triglycerides, and to increases in HDL cholesterol levels. Red wine Red wine contains flavonoids, which inhibit LDL oxidation (the process whereby LDL cholesterol adheres to artery walls). Studies have demonstrated a relationship between flavonoid consumption (from food) and reduced risk of death from coronary heart disease. Although nonalcoholic grape products contain flavonoids, red wine contains much higher concentrations of flavonoids. However, the use of alcohol is not advocated by the AHA and other organizations because of the potential for addiction and the other serious repercussions such as motor vehicle accidents and the development of hypertension, liver disease, breast cancer, weight gain. If red wine is consumed, it is recommended that men have no more than 2 glasses (20 g ethanol) per day and women, no more than 1 glass (15 g ethanol). Red Yeast Rice Red yeast rice, the fermented product of rice and red yeast, has been used in China since at least 800 AD to make wine and preserve food, and for its medicinal properties, which are believed to include, among other things, improvement in blood circulation. Recent well-designed studies have shown that red yeast rice significantly reduces total cholesterol, LDL cholesterol, and triglyceride concentrations. Chromium Brewer's yeast is an important source of chromium. Ninety percent of Americans are deficient in this important mineral. Chromium has demonstrated the ability to lower LDL levels in the blood and raise HDL levels. Vitamin B5 (Pantothenic Acid) Research has shown that vitamin B5 lowers cholesterol. Studies are currently underway to determine if this vitamin helps prevent heart disease. Herbs Hawthorn (Crataegus oxyacantha and monogyna) The flowers and berries of the hawthorn plant have been used in traditional herbal and homeopathic remedies to protect against stroke and to treat chest pain, irregular heartbeat, and heart failure. In addition, studies using rats suggest that the tincture of Crataegus (made from the berries) may be a powerful agent for the removal of LDL from the blood stream. The tincture of hawthorn berries also reduced the production of cholesterol in the liver of rats who were being fed a high-cholesterol diet. Studies to determine if hawthorn will confer the same effects in humans are needed. Green Tea (Camellia sinensis) Green tea has been observed to have a variety of beneficial effects, including anticancer and antioxidant effects. The tea has also demonstrated an ability to lower total cholesterol and raise HDL cholesterol in both animals and people. Although an animal study conducted to determine how green tea effects these changes was not conclusive, results from the study suggest that the catechins in green tea may block intestinal absorption of cholesterol and promote its excretion from the body. Garlic (Allium sativum) Long hailed for its beneficial effects, a number of studies have found that garlic reduces elevated total cholesterol levels more effectively than placebo. However, the size of the effect in these studies was small, and study limitations make it difficult to draw any firm conclusions. More research with better-designed studies is warranted in order to assess the safety and effectiveness of garlic and to determine the most appropriate dose and form (fresh garlic vs. supplements). Red clover (Trifolium pratense) Preliminary studies suggest that chemicals in red clover known as isoflavones may raise HDL levels, especially in menopausal women. Not all studies, however, have shown such positive effects. Further studies are needed before a definitive conclusion can be made. Massage and Physical Therapy While no studies have examined the effect of massage on cholesterol levels, massage has been shown to reduce cortisol (stress-related hormone) levels and to induce relaxation. Massage may therefore have an indirect effect on risk factors that result from or are worsened by stress, such as poor eating habits and obesity, cigarette smoking, or lack of exercise. Lowering cortisol levels may also have a positive effect on cholesterol levels. Mind/Body Medicine Stress Reduction Emotional and social stress increases the risk for heart disease. Stress is thought to promote hardening of the arteries and effective stress reduction techniques can help to reduce high cholesterol levels and other risk factors. In several studies of Transcendental Meditation (TM), significant reductions in total cholesterol levels as well as reductions in blood pressure, obesity, and cigarette smoking were seen after 3 to 11 months of practice. Although TM appears to be one of the more effective methods for relaxation, other methods that may be considered include: Ayurveda Guggulipid (Commiphora mukul) Guggulipid, a traditional Ayurvedic medication used to treat high cholesterol, is widely used in India and was first recommended as a treatment for hardening of the arteries in 600 BC. It appears to be an effective cholesterol-lowering agent and its healthful effects are thought to be due to its ability to block the production of cholesterol in the liver. In a 4-week study of 61 people who were on a fruit and vegetable-rich diet, half were given guggul supplements of 400 mg three times and the other half received placebo. The guggulipid group had reductions of total cholesterol, LDL, and triglycerides comparable to that seen with conventional cholesterol-lowering drugs while the placebo group had no improvement. Fenugreek (Trigonella foenum graecum) Fenugreek is a legume sold as a dried seed. It is cultivated in India and the Middle East, and used as a condiment in foods like curry and in baked goods. In Ayurvedic medicine, spices and herbs are traditionally used to treat a variety of chronic diseases. Fenugreek seeds have been shown to decrease LDL cholesterol and triglycerides, and increase HDL cholesterol levels. These effects appear to result from reduced intestinal absorption of cholesterol, and may be related to the high fiber content of the seed. Consumption of fenugreek may therefore be beneficial in the management of high cholesterol levels. Other Considerations Pregnancy Cholesterol-lowering medications should be avoided during pregnancy. Prognosis and Complications A number of complications may occur if high cholesterol is left untreated. These include: It is also important to note that lowering cholesterol too rapidly may contribute to the development of depression, which may be related to low levels of omega-3 fatty acids. Maintaining an appropriate weight, eating a low-fat diet, and exercising can have a significant impact on cholesterol levels and improve long-term prognosis. |