4 questions | Applied Sciences homework help

1. Who knows your medical secrets? It’s getting easier for health marketers, your boss, and your mortgage company to find out what ails you. Consumer Reports 65(4):22–26, 2000.

CardiovasCular disease No matter what advances there are in high-technology medicine, the fundamental message is that any major reduction in deaths and disability from heart disease and stroke will come primarily from prevention, not just cure. This must involve robust reduction of risk factors through encouraging our children to adopt healthy lifestyle habits and by introducing appropriate policies and intervention programmes. Judith Mackay, M.d.1 ca rt oo n so ur ce : f da c on su m er Chapter Fifteen Part Four Personal Health Concerns306 Keep These poinTs in Mind as You sTudY This ChapTer Key Concepts

• The more risk factors a person has, the greater the risk of developing cardiovascular disease. Heredity, gender, and age cannot be controlled, but other risk factors can be influenced by the individual’s behavior.
• Risk-factor modification can have a significant impact on both the length and the quality of many people’s life.
• The prevailing medical view is that all adults should have their blood cholesterol and blood pressure checked and take action if abnormalities are found.
• The cornerstone of a cholesterol reduction program is a balanced, low-fat, high-fiber diet plus regular aerobic exercise.

prevalenCe of CardiovasCular disease (2006 esTiMaTes) Table 15–1 Condition Prevalence* # Deaths High blood pressure 74,500,000 56,600 Coronary heart disease 17,600,000 425,400 Stroke 6,400,000 137,100 *Some individuals have more than one of the above conditions. Source: American Heart Association.2 Few health-related matters have received as much public attention as the relationships among diet, blood cholesterol levels, and heart disease. Consumers are being urged to know their cho- lesterol numbers, lower the fat content of their diet, exer- cise, and take other steps to reduce the risk of developing heart disease. The data supporting some of this advice are voluminous, complex, incomplete, and sometimes confusing. Yet, based on these data, individuals are be- ing urged to make decisions that may affect the length and quality of their life. The information in this chapter should help you make intelligent decisions based on the latest available research findings. Cardiovascular disease is also an area of explosive technologic development in both diagnostic and treat- ment procedures. As a result, increasing numbers of people will face complex decisions that can affect both their survival and their pocketbook. This chapter covers the causes, risk factors, and man- agement of the two most prevalent problems that affect the heart and blood vessels, with emphasis on strategies for prevention and treatment. The main topic is coronary heart disease, but high blood pressure, which can play a role in both heart attacks and strokes, is included because it involves some of the same considerations. Less com- mon types of heart problems, such as rheumatic heart disease, congenital heart disease, and infections of the heart, are not discussed in this book. signifiCanCe of CardiovasCular disease Cardiovascular diseases (problems affecting the heart and blood vessels) are the leading cause of illness and death for both men and women in the United States. The American Heart Association estimates that the total direct and indirect cost of treating heart attacks, strokes (due to blockage of blood supply to the brain), and other forms of cardiovascular disease in 2010 was $503.2 billion.1 About 34% of the deaths in this country are attributable to cardiovascular disease. The majority stem from atherosclerosis. Before menopause, women tend to have lower blood pressure and fewer heart attacks than do men of equiva- lent age. After menopause, the rates among women are higher than those of men and increase with advancing age. The American Heart Association2 estimates that in 2006, 81.1 million American adults had one or more forms of cardiovascular disease. Table 15-1 indicates the prevalence and mortality of the most common types. risK faCTors for CoronarY hearT disease The heart muscle (myocardium) receives its blood from the coronary arteries. In coronary heart disease (CHD), these arteries are narrowed by atherosclerosis, a condition in which fibrous tissue infiltrates from the muscular inner layer of the artery due to repeated injury to the delicate lining of the coronary arteries. These fibrous tissue formations, called plaques or atheromas (-oma = “tumor”), also incorporate fats, cholesterol, and 307Chapter Fifteen Cardiovascular Disease eventually calcium. These plaques build up on the walls of large and medium-sized arteries. As atherosclerosis progresses, the coronary arteries can narrow and make it difficult for oxygen-rich blood and nutrients to reach the heart muscle. Although atheromas can be reduced by various means, their fibrous structure makes them resistant to anything short of mechanical or surgical intervention—or possibly an intensive cholesterol- lowering program. Reduced blood supply to the heart can result in chest pain (angina pectoris) or other symptoms, typically trig- gered by physical exertion. If a narrowed blood vessel is completely blocked by a blood clot, the area of the heart just beyond the blockage is denied oxygen and nourish- ment, resulting in a heart attack (myocardial infarction). The situation is often complicated by the development of an irregular heart rhythm (arrhythmia) and/or heart failure, in which the heart’s ability to pump blood is inadequate to meet the body’s needs. Like other degenerative disease processes, athero- sclerosis can take years to develop. Inflammation appears to b instrumental in its development.3 Diet is implicated because the deposits on arterial walls contain high lev- els of fat and cholesterol. Studies of both humans and animals have shown links between dietary habits and atherosclerosis. At least nine risk factors can help predict the like- lihood of CHD: heredity, being male, advancing age, cigarette smoking, high blood pressure, diabetes, obe- sity (especially excess abdominal fat), lack of physical activity, and abnormal blood cholesterol levels. The more risk factors a person has, the greater the likelihood of developing heart disease. Heredity, gender, and age cannot be modified, but the others can be influenced by the individual’s behavior. Several of these risk factors are interrelated. Obesity, lack of exercise, and cigarette smoking can raise blood pressure and adversely influence blood cholesterol levels. A 1999 meta-analysis4 concluded that exposure to secondhand smoke increases the risk of fatal and non-fatal CHD in nonsmokers by about 30%. Some authorities believe that emotional stress is a risk factor, but the evidence for this is not clear-cut. A 10-year study of 85,000 women found that coffee consumption had no effect on the incidence of CHD in women.5 The relationship of blood triglyceride levels to cardiovascular disease is unclear, but studies suggest that triglyceride levels of 200 mg/dL or more may be an independent risk factor for CHD.6 Regardless, very high levels (over 500 mg/dL) should be treated because this can cause other problems, such as pancreatitis. Statin drugs may work by decreasing inflammation as well as by lowering cholesterol. C-reactive protein (CRP) is a marker for inflammation that is associated with cardiovascular risk, especially when a sensitive version of the test—highly sensitive C-reactive protein (hs-CRP)—is used. In the JUPITER trial, healthy people with normal cholesterol levels but high CRP levels who were given a statin drug had significantly fewer heart attacks and deaths. Some doctors are measuring CRP in patients with other risk factors to help them decide which patients need more aggressive treatment, but it has not proven useful as a screening test for the general population. Studies done in the 1980s and 1990s linked elevated blood levels of homocysteine to increased risk of prema- ture coronary artery disease, stroke, and venous blood clots, even among people with normal cholesterol levels. These studies led to speculations that high homocysteine levels are a risk factor that contributes to atherosclero- sis. Supplementation with folic acid, vitamin B6 and/or vitamin B12 can lower abnormal levels, but controlled clinical trials have found no benefit from doing so.7 Other biomarkers include apolipoprotein A1 (in HDL), lipoprotein(a), fibrinogen, PAI-1, asymmetric dimethylarginine, brain natriuretic peptide and NT- proBNP). Research is ongoing, but so far these are not recommended for screening tests or treatment. Many studies have demonstrated that risk-factor reduction is beneficial. The most important study be- gan in 1948 in Framingham, Massachusetts, and is still generating valuable information. A recent analysis based on 50 years of data from this study found that high levels of physical activity, never smoking (men), and normal weight were each associated with a 20% to 40% lower risk of developing cardiovascular disease and an increase in life expectancy of 3 to 4 more years than occurs with low physical activity, current smoking and obesity, respectively.8 Adding stress management to the intervention mix does not appear to improve outcomes.9 The age-adjusted death rates due to coronary artery disease and stroke have fallen steadily for more than 25 years. This is due to advances in diagnosis and treatment as well as lifestyle changes that lower the risk for the disease.10 Table 15-2 can help you evaluate your risk of devel- oping coronary heart disease and what to do about it. Blood lipid levels Lipid is the general term for fatty substances, includ- ing triglycerides (fats and oils), phospholipids (such as Part Four Personal Health Concerns308 WhaT Can Be done aBouT Major Chd risK faCTors Table 15–2 Risk Factor Heredity Gender Age Tobacco High blood pressure Diabetes Obesity Lack of exercise Abnormal cholesterol levels Criteria Family members with CHD, especially at a young age Familial hyperlipidemia Male gender (Note: women's risk increases after menopause) Progressively greater risk as age increases Cigarette smoking and other forms of tobacco Exposure to secondary smoke Pre-hypertension: 120–139 systolic or 85–89 diastolic Hypertension: over 140/90 Diagnosis by doctor using standard tests BMI over 25, especially accumulation of abdominal fat Less than recommended amount of at least 30 minutes of moderate aerobic exercise 5 days a week HDL under 40 Total cholesterol over 200 LDL cholesterol: Under 100: optimal 130-159: borderline high risk Over 160: high risk Actions to Take Not modifiable, but a reason for more aggres- sive control of modifiable risk factors Not modifiable Not modifiable Stop smoking, and avoid exposure to others who smoke. Dietary modification, weight control, exer- cise, smoking cessation; medication when needed Dietary modification, weight control, and exercise; medication, insulin as needed to control blood sugar Weight loss Exercise more; even small increases are helpful Diet, exercise, weight control Medication when needed lecithin), and sterols (including cholesterol). In common usage, fats are lipids that are solid at room temperature, whereas oils are lipids that are liquid at room tempera- ture. (See Chapter 10 for a discussion of the types of fat found in foods.) Blood lipids is a term used to describe the fatty substances circulating within the bloodstream. Cholesterol is found only in foods of animal origin and is part of every animal cell. It is essential to life, be- cause the body uses cholesterol to make cell membranes, hormones, and bile acids, as well as for other functions. Most of the cholesterol the body uses is manufactured within the body, mainly within the liver. When dietary cholesterol intake is high, the liver tends to compensate by lowering cholesterol production. Because cholesterol is a fatlike substance and can- not mix with water, the body transports it in protein- containing packages that can flow smoothly throughout the bloodstream. These packages, called lipoproteins, are composed of various amounts of cholesterol, triglycerides (fats), phospholipids, and other special proteins. Serum lipoproteins are classified according to den- sity. The three main cholesterol-protein combinations are high-density lipoproteins (HDL), low-density lipopro- teins (LDL), and very-low–density lipoproteins (VLDL). Medical management, however, is based mainly on the levels of total cholesterol, HDL, and LDL. People with high blood levels of HDL have a low risk of developing coronary heart disease.11 Although the reason for this is not certain, many scientists believe that HDL serves as a “scavenger” that transports choles- terol from various cells to the liver, from which it can be excreted in the bile. This helps protect blood vessels against atherosclerosis. HDL may also have some ability to remove cholesterol that has already been deposited in atherosclerotic plaque. Low-density lipoproteins contain about 60% to 70% of the cholesterol carried in the bloodstream. Therefore, when a blood test indicates that total cholesterol is high, this usually means that LDL is undesirably high, but some people (most notably endurance athletes) with high total cholesterol levels have high HDL rather than high 309Chapter Fifteen Cardiovascular Disease LDL. Because the cholesterol from LDL tends to accu- mulate in the arteries as a component of atherosclerotic plaque, LDL is often called “bad cholesterol,” whereas HDL is called “good cholesterol.” Since the cholesterol both contain is identical, it would be more accurate to refer to them as good or bad lipoproteins. Long-range studies of large population groups have shown that the higher the total cholesterol and LDL lev- els, the greater the risk of a heart attack (Figure 15-1). In 1987, for example, the Framingham Study researchers reported that among people younger than 50, overall deaths rose 5% and heart-related deaths rose 9% for each 10 mg/dL of total cholesterol.13 Other studies have shown that lowering the cholesterol level through dietary and/or drug treatment decreases the incidence of heart attacks.14,15 For middle-aged men it appears that each 1% reduction in LDL results in a 2% reduction in risk of a heart attack or death from CHD.16 A type of LDL called lipoprotein(a), or Lp(a), has been identified as a possible independent risk factor for CHD, but the data are conflicting.17 Lp(a) has a strong genetic component and is not influenced by diet or most cholesterol-lowering drugs. Although it may turn out to be an important factor in the development of heart disease for some people, no studies have defined what practical steps can be taken to lower abnormally high levels. One study, however, found that lowering elevated LDL appears to reduce the risk of high Lp(a).18 Another study found no association between Lp(a) concentration and the risk of stroke.19 CholesTerol guidelines Cholesterol and other blood lipids are measured in milligrams per deciliter (mg/dL—a deciliter is 100 ml, about 1/10 of a quart). Total cholesterol, HDL, and tri- glyceride levels are determined by laboratory tests that measure them directly. LDL can be measured directly or calculated by subtracting HDL plus one-fifth of the triglyceride level from total cholesterol. The test to determine total cholesterol, HDL, LDL, and triglyceride levels is called a lipoprotein analysis, or lipid profile (Figure 15-2). Because triglyceride levels are immediately influenced by eating, the blood specimen figure 15-1. Relationship between serum total cholesterol level and CHD death rate. Based on data from 361,662 men screened for the MRFIT study.12 Serum Cholesterol (mg/dL) 10 -y ea r C

HD D

ea th R at e pe r 1 00 test in range out of range units reference range LIPID PROFILE TRIGLYCERIDES 165 MG/DL 20–190 CHOLESTEROL, TOTAL 210 MG/DL LESS THAN 200

HDL-CHOLESTEROL 50 MG/DL GREATER THAN 39

LDL-CHOLESTEROL 127 MG/DL LESS THAN 130 CHOL/HDL-CHOL RATIO 4.20 (CALC) < OR = 4.97 result name

COLLEGE, JOEL 21 2/9/05 987-65-4321

age date id # figure 15-2. Sample laboratory report of a male college student whose total cholesterol value is in the borderline high-risk range. The HDL level is ample. The cholesterol/HDL ratio, a measure of risk, is below average for a male. The student should be counseled about risk factors, lower the fat content of his diet, and be rechecked in a year or two. Part Four Personal Health Concerns310 figure 15-3. Simplified version of the NCEP’s recommendations for adults with no evidence of heart disease. The positive risk factors are age (male ≥45 years, female ≥55 years or premature menopause without estrogen therapy); family history of premature coronary heart disease; smoking; high blood pressure; HDL <40 mg/dL; and diabetes. If HDL ≥60, subtract 1 risk factor from the total of the others. For people with two or more risk factors, 10-year risk is estimated to determine whether intensive treatment is indicated. The Web page http://hin.nhlbi.nih.gov/atpiii/calculator.asp?usertype=prof enables consumers to calculate their risk. must be collected after a fast of 9 to 12 hours, usually done overnight. In 1987 the National Heart, Lung, and Blood Insti- tute’s National Cholesterol Education Program (NCEP) recommended that all Americans ages 20 and older have their total blood cholesterol level measured as part of a routine medical evaluation that also considers other risk factors for heart disease. In 1993 the guidelines were revised to add screening for low HDL levels. In 2001, the guidelines were revised again to emphasize primary prevention in persons with multiple risk factors and more aggressive treatment of people with known CHD. Table 15-3 summarizes NCEP’s cholesterol-level classification system. About 50% of Americans have a total cholesterol level of 200 or above. NCEP’s current guidelines20 call for measuring total cholesterol and HDL at least once every 5 years begin- ning at age 20. The most efficient way to do this is to use a lipid profile as a screening test. If total cholesterol is 240 or more or HDL is less than 40, the test should be repeated. If the first and second LDL levels are similar, the results are averaged. If they are more than 30 mg/dL apart, a third test is done and averaged with the others. Figure 15-3 summarizes NCEP’s recommended actions for adults who do not have heart disease. For those who do, the recommended treatment is based on the individual’s average level of LDL and number of risk factors.21 Regardless, dietary measures and exercise should be the cornerstone of any treatment program. Problems with Lipid Screening Tests Management of cholesterol levels is complicated by the fact that laboratory tests have considerable potential for error. Test results can vary from sample to sample, and some facilities do not perform the test accurately. Levels vary at different times within the individual. How the test is done also influences the results. Food intake, changes of position (lying down, sitting, or stand- ing), weight change, alcohol intake, various illnesses, and the technique used to collect the specimen can cause variations. “Finger-stick” tests sometimes used in mass screenings are not as accurate as tests using blood drawn from the arm. An erroneously high reading can cause needless wor- ry and expense. An erroneously low reading can lead an individual to fail to take appropriate action. Considering nCep ClassifiCaTion of seruM CholesTerol levels (Mg/dl)* LDL-cholesterol Under 100 Optimal 100–129 Near optimal/above optimal 130–159 Borderline high-risk 160–189 High 190 or more Very high Total cholesterol Under 200 Desirable 200–239 Borderline high 240 or more High HDL-cholesterol Under 40 Low 60 or more High Table 15–3 *Many scientific publications follow the Systeme International, which expresses cholesterol values in millimoles per liter (mmol/L). To convert mg/dL to mmol/L, multiply by 0.02586 and round off to the nearest 0.05. Thus 200 mg/dL would be 5.15 mmol/L, and 130 mg/dL would be 3.35 mmol/L. Get lipid analysis after a 9- to 12-hour overnight fast. Maintain good health habits. Get tested again within five years. Is your LDL 160 or more?

YES NO

Change your lifestyle: eat less fat, exercise aerobically, control your weight, don’t smoke. Do you have two or more risk factors?

YES

Make lifestyle changes. If that does not improve your blood cho- lesterol levels sufficiently, drug therapy may be advisable. NO Is your LDL 130 or more?

YES NO

Is your HDL under 40?

YES NO

311Chapter Fifteen Cardiovascular Disease the test’s relatively low cost and the problems that can result from an inaccurate report, it is wise to obtain the test from a laboratory recommended by one’s personal physician. Although the FDA has approved a home cholesterol test kit, this test is rarely practical because it measures only the total cholesterol level. Current guidelines for screening include HDL testing and a lipid profile for anyone whose total cholesterol is high. Unnecessary expense can be avoided by starting with a lipid profile ordered through a physician’s office. dieTarY ModifiCaTion Most of the cholesterol the body needs is produced in the liver. The rest is derived from animal products (meat, fish, milk, eggs) in the diet. Among the dietary factors, the amount and type of fat eaten have the greatest impact on the blood cholesterol level. Decreased consumption of saturated fats usually results in lower blood cholesterol, as does substitution of polyunsaturated or monounsatu- rated fats for some saturated fats in the diet. Trans-fatty acids, commonly found in margarine, pastries, and fat-containing snack foods, tend to reduce HDL and increase LDL.22 The labels of products con- taining trans-fatty acids list “partially hydrogenated oil” as an ingredient. The FDA requires that the amount of trans-fatty acids be listed on product labels.23 Dietary cholesterol affects the level of blood choles- terol, but to a lesser and more variable extent than does the fat content of the diet. A high intake of soluble fiber (found in oat products, beans, and some other complex carbohydrate foods) can help to lower blood cholesterol levels. Studies have shown that people who consume more vegetables, fruits, and cereal fibers have a lower incidence of coronary heart disease.24,25 Table 15-4 describes the Therapeutic Lifestyle Changes (TLC) diet recommended for cholesterol re- duction. Dietary change must be permanent. Currently, about 37% of Americans’ total caloric intake is from fat. The TLC diet would reduce this to 25% to 35%. Dietary cholesterol intake, which typically is 350 to 450 mg/day, would be reduced to less than 200 mg/day. Diets limited to 10% fat are more effective in lowering total blood cholesterol and LDL values,26 but few people are willing to change their diet that drasti- cally. Mirkin and Rich27 have noted that for most adults, a 10% fat level will be achieved by limiting daily fat intake to 20 g. Questions have been raised about whether lowering cholesterol increases the risk of certain cancers.28 The predominant medical view is that it does not.29 To assist consumers trying to improve their blood cholesterol levels and reduce their risk of cardiovascular disease, the American Heart Association30 recommends these general guidelines:

• Balance calorie intake and physical activity to achieve or maintain a healthy body weight.
• Consume a diet rich in vegetables and fruits. • Choose whole-grain, high-fiber foods. • Consume fish, especially oily fish, at least twice a week. • Limit your intake of saturated fat to 7% of energy, trans fat to 1% of energy, and cholesterol to 300 mg per day by: • Choosing lean meats and vegetable alternatives • Selecting fat-free (skim), 1%-fat, and low-fat dairy products • Minimizing intake of partially hydrogenated fats
• Minimize your intake of beverages and foods with added sugars.
• Choose and prepare foods with little or no salt. • If you consume alcohol, do so in moderation. • When you eat food that is prepared outside of the home, follow the above recommendations.

The first practical step toward dietary change is to become more aware of one’s diet, especially the amount of food eaten and the brands usually purchased. Toward this end, consumers should get into the habit of check- ing labels to determine the amount of cholesterol and the amount and type of fat. They should also be aware of the “hidden” fats found in processed foods such as cookies, crackers, and snack cakes, and the kinds of fats and oils used in their own cooking. nuTrienT CoMposiTion of The TherapeuTiC lifesTYle Changes (TlC) dieT Table 15–4 Nutrient Category Saturated fat Polyunsaturated fat Monounsaturated fat Total fat Carbohydrates Fiber Protein Cholesterol Total calories Recommended Intake Less than 7% of calories Up to 10% of calories Up to 20% of calories 25% to 35% of calories 50% to 60% of calories 20–30 g/day Approximately 15% of calories Less than 200 mg/day Balance energy intake and expen- diture to maintain desirable body weight/prevent weight gain Part Four Personal Health Concerns312 The next step is to make substitutions for red meats. For example, leaner beef cuts (select or choice) can be substituted for fatter cuts (prime), and consumption of fish, poultry, fresh fruits and vegetables, beans, and other legumes can be increased. Foods high in com- plex carbohydrates—such as whole grains, beans, and vegetables—can be made the “main dish,” with small amounts of red meats and cheeses becoming the “side dishes.” Mixed dishes such as stews, casseroles, and pasta and rice meals can combine small amounts of meat with other foods, such as grains or vegetables. Finally, consumers should evaluate their progress by having their blood cholesterol tested within a few months and then periodically as recommended by the professional who is guiding them. The goal should be a gradual but steady reduction in the total cholesterol and LDL-cholesterol levels. Because the major sources of saturated fat in the American diet traditionally have come from beef and dairy products, dietary advice aimed at lowering blood cholesterol often focuses on cutting back on hamburgers and fatty meats, whole milk, and cheeses—and getting into a habit of preparing foods with less fat. The “Dietary Modification” box suggests how to reduce the fat and cholesterol content of one’s diet. Food companies have responded to public concern by marketing thousands of products that are fat- and cho- lesterol-reduced. However, shoppers should not assume that products labeled as “reduced fat” or “% fat-free” are low in fat. If a package says “95% fat-free,” that merely means that 95% of the product’s weight doesn’t contain fat. The rest can be anything, including water. Many products with “% fat-free” claims contain more than 25% to 50% of their calories as fat, and many “reduced fat” products have more than 50% of their calories as fat. For this reason, shoppers seeking to determine fat content should inspect the “Nutrition Facts” box and divide the fat calories per serving by the total calories per serving. Some observers—most notably Gary Taubes31— postulate that low fat diets have been counterproduc- tive, leading Americans to replace fats with more carbohydrates, gain weight, and increase their risk of cardiovascular disease. They cite evidence suggesting that carbohydrates, not fats, might be the sole cause of obesity and also cause heart disease, diabetes, cancer, and many other diseases. But Hall32 notes that Taubes discredits what he calls the “low fat myth,” only to re- place it with his own “low carb myth,” and he admits that these competing ideas have not yet been properly tested. Pending proper testing, the most reasonable course is to accept the current consensus of experts. Dietary Analysis Following the guidelines in the “Dietary Modification” box will reduce the fat, saturated fat, and cholesterol content of the diet and should come close to the fat and saturated-fat levels recommended in the NCEP’s TLC diet. However, the only way to determine how much fat and cholesterol are actually consumed is to calculate the amounts contained in one’s daily diet. The MyPyramidTracker Web site (www.mypyramidtracker. gov) offers a practical way to do this. After setting up a password-protected account, the user can construct a favorite-food list and enter data each day to determine the overall fat percentage as well as how one’s diet compares to the Dietary Guidelines for Americans. Computer programs are also available for determin- ing fat and cholesterol intake. Those containing large databases, including nutritional analyses of brand-name products and fast food items, generally provide the most accurate information. Computer programs are accessible to consumers at certain clinics and through nutrition professionals in private practice. Some are also marketed directly to the public for home use. The USDA maintains a food composition database33 at www.nal.usda.gov/fnic/ foodcomp. Despite these aids, some consumers wishing to design a diet that is significantly low in fat would be wise to consult a registered dietitian or other profes- sional nutritionist. Chapter 10 describes the training and credentials of nutrition professionals. Soluble Fiber Controlled studies have demonstrated that a diet high in soluble fiber can improve blood cholesterol levels.34 Well-controlled intervention studies have shown that four major water-soluble fiber types—beta-glucan, psyl- lium, pectin, and guar gum—effectively lower serum LDL without affecting HDL. It is estimated that for each additional gram of water-soluble fiber in the diet, serum total and LDL cholesterol concentrations decrease by about 1 mg/dL. It appears likely that soluble fiber interferes with the (re)absorption of bile acids from the intestine into the liver, causing the liver to pull more LDL from the bloodstream. Epidemiologic studies suggest that a diet high in water-soluble fiber lowers the risk of cardiovascular disease. The foods highest in soluble fiber include oat bran, dry oats, kidney beans, navy beans, pinto beans, lima beans, white beans, Brussels sprouts, kale, broccoli, plums, apples, oranges, and grapefruit (including the fibrous partitions). Large amounts of fiber increase the bulk of the stool and can cause bloating, cramps, and diarrhea. However, discomfort can be minimized or 313Chapter Fifteen Cardiovascular Disease The following can help you choose and prepare foods lower in saturated fat and cholesterol:

• Trim all visible fat from beef and poultry, and remove the skin from poultry before eating.
• Bake, broil, or roast meat dishes instead of deep- fat–frying them. To prevent drying and to add flavor, baste with wine, lemon juice, or a low-fat broth.
• Try experimenting with herbs and spices, such as dill, tarragon, cilantro, and basil.
• Avoid fatty gravies and sauces.
• If pan- or stir-frying, use a small amount of vegetable oil such as canola or safflower oil; also increase your use of olive oil.
• Minimize use of butter.
• Minimize use of products, such as margarines, that contain partially hydrogenated oils (trans-fatty acids).
• To cut down on whole-milk products, switch to 2% or 1% milk, and perhaps eventually to skim milk. Many people find it easy to get accustomed to low-fat milk, and that when they do so, whole milk tastes too rich. Use the low-fat or skim-milk versions of ricotta, cottage, and mozzarella cheese. Fat-free and low-fat farmer and pot cheeses also are available. All these cheeses should contain no more than 2–6 g of fat per ounce. For desserts, substitute ice milk, frozen yogurt (especially the nonfat variety), sherbet, or sorbet for ice cream. If you do eat ice cream, choose regular rather than super premium types.
• Limit consumption of foods that contain palm, palm kernel, and coconut oils; lard; butter; unidentified shortening; egg-yolk solids; and whole-milk solids. Also, cut down on baked goods made from these ingredients or that are fried, such as doughnuts.
• Use nonfat or low-fat yogurt instead of sour cream in dips and toppings.
• Use only the egg whites or discard every other yolk in recipes requiring eggs (2 whites = 1 whole egg in recipes). Or try a commercial cholesterol-free egg substitute.
• Reduce the amount of fat in recipes by one-third to one-half, and use chiefly polyunsaturated and mono- unsaturated oils.
• Shrimp, lobster, and other shellfish may be eaten occasionally because they are lower in cholesterol than previously thought, and do not contain too much saturated fat.

dietary modification for cholesterol control

• In coffee, instead of using a nondairy creamer that contains saturated fats, use low-fat or skim milk, skim milk powder, or a fat-free nondairy creamer.
• Substitute rice and pasta for egg noodles.
• Make your own popcorn for a low-calorie snack, but be sure to omit the melted butter. Beware of high-fat microwave popcorn products.
• Avoid nuts that are high in saturated fats, such as coconuts and macadamia nuts.
• Incorporate oat fiber into your diet, for example, in oat bran muffins or in casseroles. To increase total fiber intake, look for the words “whole wheat” or “whole grain” near the top of the ingredient list when buying breads and cereals.
• Use fresh fruit instead of high-fat desserts.
• Choose low-fat luncheon meats such as chicken or turkey breast instead of salami and bologna. Use frankfurters, other sausages, and bacon sparingly. When eating poultry, remember that white meat has less fat than dark meat.
• Buy or make salad dressings with predominantly un- saturated oils. Olive oil is an especially good choice. Or try a nonfat type or just vinegar or lemon juice.
• Limit use of organ meats that are very high in choles- terol, such as liver, kidneys, brain, and sweetbreads.
• Prepare soups and stews containing meat the day before eating them. After refrigerating, skim off the congealed fat on the surface before reheating.
• Be cautious about store-bought baked products such as pies, cakes, croissants, pastries, and muffins. Try to find low-fat cookies and crackers. Or bake at home with small amounts of unsaturated oil or with pureed fruit such as applesauce or prune butter substituted for some of the oil. Angel food cake is a good choice because it is low in fat and cholesterol.
• Use some of the many fat-free, cholesterol-free prod- ucts marketed as substitutes for products that nor- mally are high in fat. But don’t eat so much of them that you lose control of your weight.
• Make changes gradually to avoid feeling deprived. For most people, enjoying a rich dessert or a prime rib once in a while is not going to significantly affect their cholesterol level as long as the overall choles- terol-lowering diet is followed most of the time. It is better to splurge once in a while than to cheat a little bit each day.

Source: Quackwatch Web site.35 Part Four Personal Health Concerns314 prevented if the amount of dietary fiber is increased gradually, so the body can become accustomed to it. Helpful Fatty Acids Randomized, controlled studies have demonstrated that consuming omega-3 fatty acids in fish or supplements can decrease the progression of atherosclerosis and re- duce the risk of heart attacks and strokes among people with proven coronary artery disease. The best known fatty acids are eicosapentaenoic acid (EPA) and doco- sahexaenoic acid (DHA). Additional studies are needed to evaluate whether apparently healthy people will also benefit. Meanwhile, the American Heart Association36 recommends:

• Patients without documented coronary heart disease should eat a variety of (preferably oily) fish at least twice a week and include oils and foods rich in alpha-linolenic acid (flaxseed, canola, and soybean oils; flaxseed and walnuts)
• Patients with documented coronary heart disease should consume approximately 1 g of EPA+DHA per day, pref- erably from oily fish. EPA+DHA supplements could be considered in consultation with a physician.
• Patients needing triglyceride-lowering should take 2 to 4 g of EPA+DHA per day provided as capsules under a physi- cian’s care.

A prescription drug fish-oil capsule (Lovaza) that contains 47% EPA, 38% DHA, and 17% other omega-3s has been FDA-approved as an adjunct to diet for lowering very high triglyceride levels in adults. It is best to minimize or avoid fish that may be contaminated with mercury. The fish highest in omega-3 fatty acids and low in mercury include Atlantic salmon, Atlantic herring, canned pink salmon, whitefish, Atlantic mackerel, rainbow trout, bluefish, and oil-canned sardines. In 2003, Consumer Reports37 reported that its tests of 16 brands of fish-oil supplements found that all contained the amounts of fatty acids stated on their labels and were not contaminated, but prices varied considerably. Regression of Atherosclerosis Many studies have shown that improving blood- cholesterol levels can reduce the incidence of and mortality from heart disease and that the greater the LDL reduction, the better the results.38 Some drug trials have used angiography or ultra- sound procedures to determine whether coronary athero- sclerosis has increased (progressed), remained the same, or decreased (regressed) during a treatment period. This is done by measuring areas of narrowing and blood flow within the coronary arteries. √ Consumer Tip A Quick Fat-Chemistry Lesson You need not know the chemical structure of fats to understand a low-fat diet. But for those who want a technical explanation, here it is. Fats are classified by the amount of hydrogen in the fatty acids that make up their basic structure. Fatty acids are composed of chains of carbon atoms tied together: –C–C–C–C–C–C–C–C–C–C–C–C–. . .

Each carbon atom has four arms that can attach to other elements:

–C–

All the arms must be attached to something else. Fatty acids have hydrogen atoms attached to the carbons: H H H –C–C–C–. . . H H H All carbons have four binding arms. All hydrogens have one. Some carbons do not have hydrogen attached to them. They have to bind to something else, so they bind twice to the next carbon. This is called a double bond: H H –C–C=C–C–. . . H H H H Fatty acids are classified by the number and location of their double bonds. Those with no double bonds are called saturated: H H H H H H H –C–C–C–C–C–C–C–. . . H H H H H H H

Fatty acids that contain several double bonds are called polyunsaturated:

H H H –C–C–C=C–C=C–C–. . . H H H H H H H Fatty acids with only a single double bond are called monounsaturated: H H H H H –C–C–C=C–C–C–C–. . . H H H H H H H All fatty acids have a carbon end and an acidic end. Polyunsaturated fats are further classified by where their double bonds are located. Those with the double bond three atoms away from the carbon at the nonacidic end of the chain of carbons are called omega–3s: H H H H H H–C–C–C=C–C–C–C–. . . H H H H H H H Gabe Mirkin, M.D. 315Chapter Fifteen Cardiovascular Disease carbohydrates. It allows 3.5 oz of fish, poultry, or lean meat per day, which makes it almost a vegetarian diet. The diet is part of an overall program that includes exercise and prohibits smoking and alcohol intake.45 During 2011, the first week of the residential program at the Pritikin Longevity Center & Spa in Miami, Florida, cost $3950 or more, depending on the season, type of room, and chosen program. Subsequent weeks cost less. Pritikin claimed that his program helped many people with heart disease, obesity, diabetes, and other health problems. The overall approach is similar to con- ventional therapy for cardiac patients but uses a more restrictive diet. The Pritikin diet can achieve consider- able reductio

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