During the first half of the twentieth century, the morbidity and mortality rates of Americans shifted away from acute infectious diseases to predominantly chronic illnesses related to lifestyle. Of the approximately 2.4 million deaths in the United States in 2003, 28% were due to cardiovascular disease, 23% were due to cancer, and 6% were due to cerebrovascular disease. There is good evidence that personal lifestyle (what and how much we eat and drink, amount and type of exercise we engage in, whether we smoke, and how we deal with daily stress) is strongly related to these three leading causes of death.

Some still hope that the way to reduce the magnitude of chronic disease lies in improved medical technology, but an increasingly prevalent view is that technology can play only a limited role. Although there have been several spectacular technological successes (e.g., organ transplants), these achievements generally affect a relatively small number of people. Despite these advances and the increase in our knowledge about chronic diseases, there has been little change in the last 40 to 50 years in the rates of these major diseases (1). Many physicians now believe that advances in medical technology will have little impact on the overall health of Americans, and that control of the current major health problems depends directly on modification of individual behavior and lifestyle habits (2). For the physician, this will involve more than telling patients with high blood pressure to cut back on salt or writing a prescription for a calcium channel blocker. The patients will need to know how to read nutrition labels and, specifically, how to monitor their sodium intake. It will involve more than telling patients with high cholesterol to cut out fats from their diets or writing a prescription for a statin. They will need to know the difference between saturated and unsaturated fats and specifically how to monitor them in their diets. In addition, in a country where half the population is overweight and one fourth of the population is obese, it will involve a lot more than just telling obese patients to cut down their calorie intake and get more exercise.

Therefore, primary care physicians who want to have a long-term impact on the health of their patients must become involved in educating them and helping them change their behavior. In fact, the U.S. Preventive Services Task Force and the American Heart Association recently have recommended that all primary care providers counsel all their patients about healthy diets and regular physical activity (3,4). You may wonder why primary care physicians have not been more involved in prevention efforts against the major lifestyle-related diseases. The answer is complex,
but some reasons are clear. Few medical schools include the necessary training for young physicians to assume these roles. Historically, emphasis has been on treating sick patients, and the rewards in terms of money, prestige, and a sense of accomplishment act as powerful reinforcements for physicians to maintain their focus almost exclusively on these aspects of medical practice. Despite the shift from acute to chronic diseases and the obvious logic inherent in prevention, it will be quite difficult to change the situation very rapidly because the reward system in medicine is so heavily geared toward waiting until people are ill to treat them. For now, the impetus for change will have to come from individual physicians who decide to put their emphasis on preventing diseases.

Most physicians do not realize that their every word and action can be regarded as a form of health education, not only by patients and their families but also by the whole community. It is not a question of whether primary care physicians are providing health education for their community, but whether they are doing it well or poorly. Primary care physicians should speak out about the benefits of physical activity and other aspects of a healthy lifestyle. They should be a major community resource for health education, and they should be involved in coordinating access to other community health resources and organizations.

The call for changing destructive lifestyle habits comes from many sources, but primary care physicians have one of the best opportunities to help people initiate positive change or prevent the formation of negative habits because of the respect that their role has in our culture and their potential to influence the health practices of families. New attitudes and skills will be required of physicians who choose this path. They will need the ability to confront without being judgmental. They must recognize that old, unhealthy habits are hard to change and there are numerous social inducements and pressures to maintain or start these habits and discourage the adoption of healthier ones. Dealing with discouragement by both the patient and physician will be a necessary part of the effort. However, it has been demonstrated repeatedly that patients can change habits and lifestyles with the help of their physicians and the support of their families.

A study of access to health care (5) indicated that 90% of the American population has a usual source of health care and that 80% had seen a physician within the previous 12 months. Another study (6) indicated that 54% of all patient encounters involved primary care physicians (family practice, general practice, pediatrics, or internal medicine). The average encounter is sufficiently long to allow at least some minimal counseling on fitness and activity, even if such counseling is not directly related to the reason the patient is seeing the physician. Even so, physicians did this in less than 10% of these encounters. Several studies have shown that patients expect their physicians to be concerned about their health habits and to actively encourage appropriate lifestyle changes, including recommending fitness activities (7,8). Given the number of people that have contact with (9) and can be influenced by primary care physicians (10), the potential impact on the total health picture in our society can be enormous.

Much work remains to be done to define the impact of habitual physical activity and exercise on various chronic diseases, but a clear and consistent picture is emerging with regard to several major diseases (11,12,13,14,15,16,17,18). The relation of physical activity to coronary heart disease (CHD) has received the most attention so far. Many studies have shown that physical inactivity and lack of exercise are associated with increased risk of CHD, whereas habitually active individuals have reduced risk of CHD and sudden cardiac death (11,19,20,21,22,23,24,25,26,27,28,29). These associations hold good even when other risk factors such as age, smoking, hypertension, family history, and obesity are taken into account. In a variety of ways, it was shown that “Selection” (i.e., sick or unfit persons are less active) was not an explanation for these findings. There is a transient rise in the risk of a cardiac event during vigorous exercise, but this risk is outweighed by an overall reduction of risk during nonexercise periods (30). A number of recent studies indicate that habitual activity is associated with decreased risk of stroke (31,32,33,34). Paffenbarger et al. (35) report that mortality rates from all causes are reduced by one fourth to one third in individuals who expend 2,000 or more kcal during exercise per week as compared with those who are less active. A major conclusion of this study is that regular exercise does increase life expectancy.

Other chronic diseases for which exercise appears to have an ameliorating effect include hypertension, diabetes, and osteoporosis. Several studies indicate that habitual activity is associated with decreased risk of hypertension (36,37), and these studies also suggest that exercise may improve hypertension control. Other studies have shown that exercise helps type 2 diabetic patients by reducing blood glucose levels, increasing sensitivity of insulin receptors, and increasing the effectiveness of insulin (38,39,40,41,42,43,44). Although few controlled studies have been completed on whether exercise will prevent or postpone the development of type 2 diabetes, such a possibility is strongly implied by the metabolic and hormonal effects produced by regular exercise. There is a lack of research data on the effects of exercise in insulin-dependent diabetic patients, but physical activity is generally recommended as an important part of an overall treatment program. There is evidence that exercise and physical activity are inversely related to the development of specific types of cancers (45,46,47,48,49,50,51). The same is true for osteoporosis (52,53,54,55,56). These studies do indicate that the protective effect of exercise holds true only for weight-bearing activities; non–weight-bearing activities such as swimming apparently do not reduce bone loss.

Regular exercise also appears to effect mental health (57,58,59,60). Taylor et al. (61) reviewed a number of studies and concluded that physical activity and exercise are associated with improved self-concept and confidence, alleviation of symptoms of mild-to-moderate depression, reduction of
anxiety, and alteration of some aspects of the stress response and coronary prone (type A) behavior.

Regular aerobic exercise has been increasingly recognized as an important factor in the prevention and control of obesity (62,63,64,65,66,67). Aerobic exercise is a vital element, in conjunction with dietary measures, in the weight loss programs that are most likely to achieve long-term success. It is becoming more apparent that exercise or diet alone is not likely to produce long-term weight loss, as is an appropriate combination of the two together.

Research on the effects of exercise on the various conditions has now reached sufficient quantity that extensive review articles and meta-analyses summarizing the findings (see (68,69,70,71,72,73,74)]), including the importance of exercise and diet in treating metabolic syndrome, are beginning to appear (75). In a review of the effect of physical fitness (as opposed to just physical activity) on total mortality, Erikssen states that a sedentary lifestyle may be as detrimental to health as smoking (76).

There is still room for debate on some of the specifics related to the impact of habitual activity and exercise on various chronic diseases, but evidence from reviews such as those cited above and from longer term studies such as Paffenbarger et al. (35

Stay updated, free articles. Join our Telegram channel

Join