Leading Causes of Death and Related Preventive Measures for Patients
By Benjamin A. Cox
This is the first place winner of the 2009 Namey/Burnett Writing Award, implemented by the ACOFP Public Health and Wellness Committee to honor the best preventive medicine papers submitted by osteopathic family practice residents and medical students.
ABSTRACT: The purpose of this essay is to examine the leading causes of mortality in the United States, the primary contributing risk factors for these conditions, and the current clinical interventions directed at prevention of these conditions. Some of the major topics of discussion include cardiovascular disease, malignant neoplasms, and cerebrovascular accidents. The major risk factors for these conditions include hyperphagia, hyperlipidemia, dyslipoproteinemia, hyperglycemia, hypertension, and the metabolic syndrome. Current clinical treatment modalities include lifestyle modifications in the realm of diet, exercise, and nutritional supplementation. Convincing findings from current research accompany the discussion, although further investigation into these modalities is warranted.
Introduction
Wouldn’t it be nice if you could just close your eyes, take a deep breath, make a wish, and have it come true? Well, with regard to your health this may actually be possible. Studies are now suggesting that using visualization and relaxation techniques helps people reduce their risk of heart disease and cancer.1 A Meta-analysis recently published in the American Journal of Hypertension concluded that meditation may result in a clinically significant reduction in blood pressure.1 In fact, it is becoming more apparent that many health issues can be managed through simple lifestyle related activities. The cumulative result of these balanced practices is the addition of healthy years to one’s life and the prevention of many of the age-related declines so commonly experienced in our culture.
Aging is defined as the cumulative changes in an organism, organ, tissue, or cell, leading to a decrease in functional capacity. In humans, this process is associated with degenerative changes in the skin, bones, heart, blood vessels, lungs, nerves, and other organs and tissues. 2 The total decrease in functional capacity of a cell, tissue, organ, or organism, ultimately, is death. Like all creatures in the animal world, human beings have a strong instinct for survival. The will to live is a force within us all. We strive for survival when our lives are threatened by a disease such as cancer. 3
This drive has also led us to seek out means to extend our survival and prevent our death. In the United States in 2002, the leading causes of death were heart disease, cancer, and stroke, followed closely by respiratory diseases and diabetes.4 These conditions are potentially preventable through the avoidance of associated contributors to risk and the balancing of specific lifestyle behaviors.5 The primary risk factors for these fatal diseases are high blood pressure, cholesterol imbalance, diabetes, obesity, poor diet, and inactivity. Smoking, alcohol, and drug use are also major risk factors due to their toxic effects. Fortunately though, the avoidance of risk factors has a synergistic effect on the cultivation of health, vitality, resilience, energy, and the homeostatic function of an organism.6 By altering key lifestyle choices, a person can drastically alter their state of physical health.5
Lifestyle Related Risk Factors
Dyslipidemia
Abnormal blood cholesterol levels can be a major concern because of the multitude of diseases associated with this risk factor. Hyperlipidemia and dyslipoproteinemia are conditions in which the lipid concentrations in the blood are out of balance and may contribute to endothelial inflammation and the development of atherosclerosis. These are associated with increased risk for coronary artery disease, peripheral vascular disease, and cerebral vascular disease. High saturated fat intake, which has been associated with dyslipidemia, has been found to be a risk factor for breast, colon, and prostate cancers.7 Atherosclerosis is a chronic disease in which thickening, hardening, and loss of elasticity of the arterial walls results in impaired blood circulation. This process develops with aging and is compounded by the hypertensive and diabetic effects on vessel walls.
Elevated levels of LDL (bad cholesterol) and decreased levels of HDL (good cholesterol) are associated with an increased risk of coronary artery disease, and can often be associated with a diet high in saturated fat. 8
Hypertension
Population-based studies have substantiated the claim that hypertension increases the risk of vascular diseases by approximately two- to three-fold.9 Hypertension has been found to be the single most significant modifiable risk factor for ischemic stroke, and the efficacy of antihypertensive treatment has been well recognized in clinical trials.10 In a summary of 17 treatment trials of hypertension throughout the world involving nearly 50,000 patients of all ages and races, there was a 38 percent reduction in all strokes and a 40 percent reduction in fatal strokes. 11
Smoking
Smoking is by far the most significant risk factor for lung cancer, as well as a significant contributor to cancers of the mouth, bladder, and kidneys.12 At the beginning of the 20th century, lung cancer was a rare disease in the United States.12 It is believed that the introduction of manufactured cigarettes, a process allowing instant availability to the masses, changed this, increasing morbidity and mortality significantly.12 Approximately 87 percent of current lung cancers are thought to occur as a result of either active smoking or passive exposure to second-hand tobacco smoke.12 Tobacco use is estimated to be responsible for more than 30 percent of all cancers and nearly one in five deaths in the United States every year.13
A study was performed at the Harvard School of Public Health on the association between smoking and the incidence of non-insulin dependent diabetes mellitus in 41,810 male health professionals aged 40-75 years, who were free of diabetes, cardiovascular disease, and cancer. It was discovered that men who smoked 25 or more cigarettes daily had almost double the relative risk of diabetes compared with non-smokers.14
Alcohol abuse
Observational studies have consistently demonstrated a direct relationship between alcohol ingestion and death from coronary heart disease.15 While mild to moderate consumption seems to have a protective effect, taking more than two drinks a day is associated with increased mortality, primarily from cancer, trauma, and cirrhosis.16
Physical Inactivity
Moderate and intense levels of physical activity have been associated with reduced incidence of coronary heart disease. Recent evidence supports a protective effect of moderate physical activity upon the incidence of stroke in men and women.17 Physical activity has been shown to impart a beneficial influence on risk factors for atherosclerotic disease by reducing blood pressure, weight, and pulse rate, raising HDL cholesterol and lowering LDL cholesterol, decreasing platelet aggregability, increasing insulin sensitivity and improving glucose tolerance, and by promoting a lifestyle conducive to changing diet and promoting cessation of cigarette smoking.18
Poor Diet (High Fat and Low Nutrients)
A Study by the Cancer Prevention Research Program that spanned 20 different countries explored the relationship between dietary fat and cancer. Cancer incidence data for breast, cervix, lung, colon, and prostate was used to clarify the association between various types of dietary fat and their effects on cancer levels. Results found that while total caloric consumption (controlled for fat intake) was not associated with cancer, total fat intake was strongly associated with cancers of the breast, colon, and prostate. Notably, monounsaturated fats had no positive associations with cancers of any measured type while saturated fat was positively associated with cancer incidence in the breast, colon and prostate.7
Based on this information, along with the known deleterious effects of high saturated fat intake on cardiovascular disease risk, professional organizations such as the American Diabetes Association, the American Heart Association, and the U.S. Department of Agriculture have made recommendations that Americans aim for a total fat intake of no more than 30 percent of calories and choose foods low in saturated fat. In addition, there is growing evidence that obesity plays a central pathogenic role in the progression of diabetes.19
Cancer research reports have indicated that a diet of lower consumption of fruits and vegetables may increase the relative chances of getting cancer if a subject is exposed to tobacco smoke. Evidence is now growing that fruits and vegetables may possess a protective effect against lung cancer.20 It has been observed that men who frequently ingest red meat or who consume large amounts of high-fat dairy products appear to have a slightly greater chance of developing prostate cancer. These men also have been found to eat fewer fruits and vegetables. It has been advised that to lower prostate cancer risk, concerned individuals should eat fewer red meats and high-fat dairy products and should consume five or more servings of vegetables and fruits each day. This recommendation may also help reduce the risk of several other cancers, as well as other health problems such as heart disease.19
The Compounding of Multiple Risk Factors
While a person may have only one of the risk factors previously discussed, it has often been observed that certain risk factors often cluster together.6 A condition known as the Metabolic Syndrome has been characterized as being composed of the following conditions:
A. Insulin Resistance/Glucose Intolerance
B. Visceral Obesity
C. Hypertension
D. Dyslipidemia
E. Pro-thrombic State
F. Microalbuminuria
G. ProInflammatory State (elevated C-reactive protein in the blood)
It is estimated that in 2005 there were more than 50 million Americans who suffered from Metabolic Syndrome, and with the obesity pandemic looming in the United States, significant increases in incidence are predicted.6 Genetic predisposition, environmental factors, and lifestyle choices have been found to be the dominant contributors to this condition.6
Current Forms of Prevention
Current treatment of the Metabolic Syndrome are primarily centered around appropriate lifestyle changes targeted at the reduction of the risk factors associated with the condition and include weight loss, exercise, proper nutrition, and dietary supplementation.
Exercise
Exercise has been observed to be an inverse risk factor for almost all the leading causes of mortality in the United States, particularly in its synergistic effect in decreasing all the other risk factors associated with premature death within the Metabolic Syndrome. Frequent exercise has long been known for its effectiveness in the treatment and prevention of cardiovascular disease.10, 21, 22, 23
A recent study of obese people, investigating the effectiveness of dietary interventions and exercise in long term weight loss, found that diet and exercise combined were associated with both a 20 percent greater initial weight loss, and a 20 percent greater sustained weight loss after one year.24
A recent review of psychiatric literature, focusing on studies on exercise, concluded that exercise and physical-activity interventions have beneficial effects across several physical and mental health outcomes, with participants engaging in regular activity displaying more desirable health including elevated mood states. 25
An investigative review of exercise spanning 61 randomized trials and more than 6,300 participants found that therapies involving exercise seem to be effective in decreasing pain, and produced marked functional improvement in adults experiencing chronic low back pain.26
A study of patients with impaired glucose tolerance, who were tracked over a period of 6 years, found that individuals engaged in a diet and exercise program exhibited a 46 percent decreased risk of developing type-2 diabetes mellitus, compared to subjects not involved in such preventative lifestyle activities. 27
Another study of 21,271 U.S. physicians found that doctors who exercise even just once a week were found to be 64 percent less likely to develop type-2 diabetes mellitus compared to those who exercised less frequently or not at all, even after adjusting for other factors including BMI, smoking, and hypertension. 28
Diet
In the examination of over-eating and its implications on overall health of a subject, one must consider the relationship between caloric intake and metabolic output. Diets high in fiber, micro-nutrients, healthy fats, and high quality protein sources, i.e. nutrient rich diets (low in empty calories), have been found to be the most effective in their promotion of health , compared to the typical western diet, high in refined carbohydrates, sugars, and saturated fat. 29
Many studies have shown that dietary interventions can improve components of the Metabolic Syndrome such as dyslipidemia, hyperglycemia, insulin resistance, and hypertension.6 A diet high in refined carbohydrates, trans fatty acids, and saturated fat will elevate serum triglycerides and free fatty acids, while a diet high in complex carbohydrates, fiber, monounsaturated fatty acids, polyunsaturated fatty acids, and omega-3 fatty acids will reduce serum triglycerides.6
Recent research into diet and aging has examined the role of extra virgin olive oil in the composition of the Mediterranean diet.30 This diet may provide longevity benefits due to the content of large amounts of fatty acids which are not easily oxidizable, and the high quality of its potent antioxidant molecules. 30 The Mediterranean diet is characterized by olive oil as the dominant fat source and moderate to high consumption of vegetables, fruits, cereal products, fish, and legumes, in combination with low quantities of meat, and wine with meals. This diet has been associated with very low rates for coronary heart disease and cancer.31
The DASH Diet, similarly rich in fruits, vegetables, whole grains, low fat dairy products and low in fat, refined carbohydrates, and sodium, has been found to reduce hypertension. DASH is the acronym for Dietary Approaches to Stop Hypertension, and is supported by the National Heart, Lung, and Blood Institute, and has been found in clinical trials to reduce coronary heart disease risk. 32
Dietary Supplementation
There exists an enormous amount of literature on the role of nutritional supplements such as vitamins, minerals, and antioxidants in health, wellness, and preventative therapy. Following are some of the most effective and evidence-supported nutritional supplements being used in clinical treatment in the United States today.
Calcium
Calcium supplements have been found to slow bone loss and have a beneficial effect on axial bone density of postmenopausal women.33 Over 80 studies have reported lowered blood pressure after calcium enrichment in experimental models of hypertension. Calcium-regulating hormones have all been found to have vasoactive properties, thus influencing blood pressure.34
Flax
Flaxseeds have been shown to exert hormonal effects, thereby beneficially affecting chronic diseases as studies show that these compounds may be involved in mechanisms for both disease prevention and treatment.35 Increased consumption of flax seed has been shown to reduce coronary heart disease mortality. 36
Monounsaturated Fats (MUFA)
In the past, nuts and seeds may have been avoided in specialized diets due to their fat content. More recent studies have demonstrated that most of this fat content is unsaturated and relatively nutrient dense. For this reason monounsaturated fats are now suggested for regular consumption in the DASH diet.37 Monounsaturated fats improve glycemic control, inhibit oxidation of LDL, improve the lipid profile and reduce blood pressure.37
Omega 3 Fatty Acids
Omega 3 fatty acids such as alpha-linoleic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have been shown to produce improvement in serum lipids with a reduction in total cholesterol, LDL cholesterol, APO-B, VLDL, triglycerides, remnant lipoproteins, and increases in HDL. Omega 3 trials have shown reductions in coronary heart death, non-fatal myocardial infarction and total mortality.
Additionally, omega-3 fatty acids have been found to increase insulin sensitivity and reduce serum glucose.38 Recent studies have found omega 3 fatty acids to be effective in the management, prevention and treatment of bipolar manic-depressive illnesses.39
Steps to Health
The key to becoming healthier is about making good lifestyle choices. Good lifestyle choices will result in increased metabolic function, resulting in a plethora of beneficial effects, decreasing hazardous risk factors, and improving a sense of well being. This increased sense of well being will encourage patients to make further healthy lifestyle choices and will synergistically result in a path to health and well being. Osteopathic family physicians are well poised to engage, educate, and empower patients to be able to follow these evidence based recommendations to improve their overall health.
Student Doctor Benjamin Cox attends Lake Erie College of Osteopathic Medicine in Bradenton, Florida where he also serves as Student Government President. He completed his thesis in preventive medicine at New College of Florida in 2006.
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