Most attention in health promotion and disease prevention programs is on tackling a handful of behaviors that have tremendous payoff, such as keep­ing fit and eating properly. In turn, these programs educate adults about good health care practices and help identify conditions such as hypertension, high cholesterol levels, and elevated blood sugar levels, which, if left untreated, can cause atherosclerosis, heart disease, strokes, diabetes mellitus, and other serious conditions.

Exercise. Ever since the ancient Greeks, physi­cians and researchers have known that exercise significantly slows the aging process. Indeed, evi­dence suggests that a program of regular exer­cise, in conjunction with a healthy lifestyle, can slow the physiological aging process (Aldwin & Gilmer, 2004). Being sedentary is hazardous to your health.

Adults benefit from aerobic exercise, which places moderate stress on the heart by maintaining a pulse rate between 60% and 90% of the person’s maximum heart rate. You can calculate your maximum heart rate by subtracting your age from 220. Thus, if you are 40 years old, your target range would be 108-162 beats per minute. The minimum time nec­essary for aerobic exercise to be of benefit depends on its intensity; at low heart rates, sessions may need to last an hour, whereas at high heart rates, 15 minutes may suffice. Examples of aerobic exer­cise include jogging, step aerobics, swimming, and cross-country skiing.

What happens when a person exercises aer­obically (besides becoming tired and sweaty)? Physiologically, adults of all ages show improved cardiovascular functioning and maximum oxygen consumption; lower blood pressure; and better strength, endurance, flexibility, and coordination (Mayo Clinic, 2008c). Psychologically, people who exercise aerobically report lower levels of stress, bet­ter moods, and better cognitive functioning (Mayo Clinic, 2008c).

The best way to gain the benefits of aerobic exer­cise is to maintain physical fitness throughout the life span, beginning at least in middle age. The ben­efits of various forms of exercise are numerous, and include lowering the risk of cardiovascular disease, osteoporosis (if the exercise is weight bearing), and a host of other conditions. The Mayo Clinic’s Fitness

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Center provides an excellent place to start. In plan­ning an exercise program, three points should be remembered. First, check with a physician before beginning an aerobic exercise program. Second, bear in mind that moderation is important. Third, just because you intend to exercise doesn’t mean you will; you must take the necessary steps to turn your intention into action (Schwarzer, 2008).

Nutrition. How many times did your parents tell you to eat your vegetables? Or perhaps they said, “You are what you eat" Most people have disagreements with parents about food while growing up, but as adults they realize that those lima beans and other despised foods their parents urged them to eat really are healthy. Experts agree that nutrition directly affects one’s mental, emotional, and physical func­tioning (Mayo Clinic, 2008c). For example, diet has been linked to cancer, cardiovascular disease, dia­betes, anemia, and digestive disorders. Nutritional requirements and eating habits change across the life span. This change is due mainly to differences in metabolism, or how much energy the body needs. Body metabolism and the digestive process slow down with age (Janssen, 2005).

Every five years the U. S. Department of Agricul­ture publishes dietary guidelines based on current

544 CHAPTER 14
research. In its Dietary Guidelines for Americans 2005 (U. S. Department of Agriculture, 2005), the USDA recommends that we eat a variety of nutri­ent-dense foods and beverages across the basic food groups. Most important, we should choose foods that limit the intake of saturated and trans fats, cholesterol, added sugars, salt, and alcohol. The USDA recommends that women of child­bearing age consume more iron-rich foods. For a more personal guide to good nutrition, check out the USDA MyPyramid website at http://www. mypyramid. gov/.

Did you ever worry as you were eating a triple­dip cone of premium ice cream that you really should be eating fat-free frozen yogurt instead? If so, you are among the people who have taken to heart (literally) the link between diet and cardio­vascular disease. The American Heart Association (2007b) makes it clear that foods high in saturated fat (such as our beloved ice cream) should be replaced with foods low in fat (such as fat-free frozen yogurt). (The American Heart Association provides a website at http://www. deliciousdeci- sions.org with recipes and alternatives for a heart – healthy diet.)

The main goal of these recommendations is to lower your level of cholesterol because high
cholesterol is one risk factor for cardiovascular disease. There is an important difference between two different types of cholesterol, which are defined by their effect on blood flow. Lipoproteins are fatty chemicals attached to proteins carried in the blood. Low-density lipoproteins (LDLs) cause fatty depos­its to accumulate in arteries, impeding blood flow, whereas high-density lipoproteins (HDLs) help keep arteries clear and break down LDLs. It is not so much the overall cholesterol number but the ratio of LDLs to HDLs that matters most in cholesterol screening. High levels of LDLs are a risk factor in cardiovascular disease, and high levels of HDLs are considered a protective factor. Reducing LDL levels is effective in diminishing the risk of cardiovascular disease in adults of all ages; in healthy adults, a high level of LDL (over 160 mg/dL) indicates a higher risk for cardiovascular disease (American Heart Association, 2007b). In contrast, higher levels of HDL are good (in healthy adults, levels at least above 40 mg/dL for men and 50 mg/dL for women). LDL levels can be lowered and HDL levels can be raised through various interventions such as exer­cise and a high-fiber diet. Weight control is also an important component.

Numerous medications exist for treating choles­terol problems. The most popular of these drugs are from a family of medications called statins (e. g., Lipitor, Crestor). These medications lower LDL and moderately increase HDL. Because of poten­tial side effects on liver functioning, patients taking cholesterol-lowering medications should be moni­tored on a regular basis.

Obesity is a growing health problem related to diet. One good way to assess your own status is to compute your body mass index. Body mass index (BMI) is a ratio of body weight and height and is related to total body fat. You can compute BMI as follows:

BMI = w/h2

where w = weight in kilograms (or weight in pounds divided by 2.2), and h = height in meters (or inches divided by 39.37).

The National Institutes of Health and the American Heart Association (see http://www. americanheart. org/presenter. jhtml? identifier=3048134 for a conve­nient calculator) define healthy weight as having a BMI of less than 25. However, this calculation may overestimate body fat in very muscular people and underestimate body fat in those who appear of nor­mal weight but have little muscle mass.

BMI is related to the risk of serious medical conditions and mortality: the higher one’s BMI, the higher one’s risk (Centers for Disease Control and Prevention, 2007b). Figure 14.4 shows the increased risk for several diseases and mortality associated with increased BMI. Based on these estimates, you may want to lower your BMI if it’s above 25. But be careful—lowering your BMI too much may not be healthy either. Very low BMIs may indicate malnutrition, which is also related to increased mortality.

Disease Risk * Relative to Normal weight and waist Circumference

BMI

Obesity

Men 102 cm (40 in) or less

Men > 102 cm (40 in)

(Kg/m2))

Class

Women 88 cm (35 in) or less

Women > 88 cm (35 in)

Underweight

< 18.5

Normal

18.5-24.9

Overweight

25.0-29.9

Increased

High

Obesity

30.0-34.9

I

High

High

35.9-39.9

II

Very High

Very High

Extreme obesity

40.0 +

III

Extremely High

Extremely High

Figure 14.4 Classification of overweight and obesity by BMI, waist circumference, and associated disease risks.

Source: Centers for Disease Control and Prevention (2007b)

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