Effects of Fats and Cholesterol on Cardiac Disease - Literature review Example

Effects of fats and cholesterol on Cardiac Disease “Incidence of cardiac disease is determined by the type of fat and cholesterol in the body, with varying metabolisms and dysfunctions.” Abstract Evidences and research in the field of health and medicine have indicated the incidence of cardiac diseases to be much higher than other fatal diseases. Researchers have attributed causes for this increase in heart diseases to life styles, eating habits, work nature and psychological status of individuals. This paper uses a research strategy to establish the relation between fat and cholesterol to cardiac diseases by studying literature and research published on the subject. Firstly, historic incidences along with progress in treatment of cardiac diseases have been briefly illustrated followed by contemporary statistics on cardiac diseases. Different researches carried out focusing specifically on relation between fat, obesity, cholesterol metabolism and cardiac diseases have been extensively studied; excerpts from these researches have been used to describe the above mentioned aspects leading to cardiac disease. Various news articles published by professional healthcare practitioners have been viewed in order to understand the potential risk factors and treatment and management of these diseases. Introduction: Cardiac or cardiovascular diseases are diseases related to the heart and heart vessels, arteries and veins. These diseases are caused due to building up of fat in the form of atheromatous plaques in the walls of arteries, which in turn blocks or disturbs flow of blood. This condition is commonly referred to as the coronary artery disease (CAD) characterized by obstruction of adequate supply and circulation to cardiac muscle and surrounding tissue. CAD is one type of Coronary Heart Disease and the most common type. This block leads to heart attack or myocardial infarction in which the heart muscle dies due to lack of circulation (Carson-Dewitt, 2009). Conditions leading to such situation outside the hospital are more common, and referred to as ischemic heart disease. Researches indicated that the main cause of this is linked to high-fat diet (Marckmann et al, 1994). The other related heart disease is that of heart muscle, referred to as cardiomyopathy. In this condition, the heart muscle, myocardium, stops functioning leading to improper or complete arrest of breathing. The major types of cardiovascular diseases are atherosclerosis (building up of plaques within arterial walls), congestive heart failure, hypertensive heart disease, cardiomyopathy (inflammatory heart disease), and valvular heart diseases (Cardiovascular diseases and conditions, 2009). Extensive research has established that high risk of cardiac diseases is associated with life styles, eating habits, and also mental conditions like chronic stress and depression. Tafet’s (2001) work explains that body metabolism includes various functions carried out by different organs in human body. All these organs require energy to function appropriately, which is supplied in the form of glucose through blood. Hormones are secreted by various organs which act as catalysts in the metabolic functions. In case of stressed conditions, the body would require more energy and glucose to handle the stress; therefore, more hormones. The main hormones involved in preparing the body for handling stress are adrenalin and cortisol. Hormones secreted by thyroid gland impact on functioning of vital body organs, including heart. These hormones help in mobilizing glucose and attaining a balance between body functions and the brain, and are produced in excess during stress, physical or mental. Adrenalin acts on fat cells thereby converting them to glucose for energy. Cortisol also increases amount of glucose in blood. Both these functions are at peak during stress conditions. Therefore, prolonged stressed conditions lead to excess release of energy and glucose. If the stress is not physical then the energy is not used, which eventually gets converted to fat and is deposited within the body. Excess fat also causes obesity and other metabolic dysfunctions, which in turn impact the mental status of the individual. These symptoms precede depression, anxiety disorder, high blood pressure and eating disorders leading to diabetes or other medical conditions (Tafet, 2001). Background and historical trend Lichtlen’s (2002) work describes that historians have traced treatment of coronary heart disease to Leonardo Da Vinci’s (1452-1519) work followed by Andreas Vesal (1514-1564). However, the exact relation between heart and blood circulation was established with William Harvey’s work after a century. This gained much more attention with Giovanni Batista Morgagni’s (1628-1771) investigation on diseases related to heart. Followed by this, Friedrich Hoffmann (1660-1742) found that coronary heart disease is caused due to reduction or obstruction of blood in the coronary arteries. Post this, until mid of 19th century, extensive work in this field of surgical medicine was carried out by many researchers and physicians; in the mid of 19th century, Herrick extended Hoffman’s discovery indicating that a slow and gradual narrowing of coronary vessels is a possible cause of obstruction of blood. Likewise, extensive work carried out in this area lead to the discovery of different types of heart diseases and their treatments (Lichtlen, 2002). Nevertheless, cardiac disease has always been on the rise. Since 1900, cardiac disease has been the cause of maximum deaths. Framingham heart study conducted in 1948 among 5000 people had established epidemiologic relationship between smoking, blood pressure and cholesterol levels and cardiac diseases, specifically coronary heart disease. Statistics have shown a two-fold increase in cardiac diseases in 2000 in U.S compared to 1940s. A report published in United States (1999) revealed that more number of people died because of cardiac diseases than cancer (Hitti, 2004), and is on the rise constantly. Contemporary statistics: Research has proven that the average life expectancy of human beings has increased by 25 years, and this is because of the drastic reduction in deaths caused due to communicable diseases with the invention of antibiotics. However, a steep increase in non-communicable diseases, specifically the cardiovascular disease, has been the cause for concern for many people in the developing countries. Research data indicated that 10 percent of world’s total numbers of deaths were due to cardiac diseases in 1990 (Howson, 1998). Also, increasing economic status of people is making them adopt Western life-style including food and drinking habits. Howson (1998) pointed out that the western-style of food habits include diet high in fat, sugar and salt; in addition, increased tobacco and alcohol consumption also adds to the existing problems. These behavioral changes have been hastened by rapid migration of large populations to the major cities of developing countries and developed countries. Another report published by the American Heart Association in 2002 also indicated that cardiac disease was the highest cause for deaths in America followed by cancer. This report also quoted that more than 70 million Americans had heart disease with 27 million people aged above 65, and by 2010 it is expected to affect 40 million people of this age group (Hitti, 2004). In Canada, almost 40% of adults have high blood cholesterol levels (Living with Cholesterol, n.d). Research related to stress and coping mechanisms indicate that obesity and metabolic dysfunctions preceding psychological distress caused by depression, anxiety disorder and eating disorders also lead to hypertension, fat accumulation, insulin resistance, thereby increasing the risk of cardiovascular diseases (Lesman-Leegte et al, 2006). Impact of fat and cholesterol on health and metabolic functions: Cholesterol is one of the main reasons associated with heart disease. Cholesterol is produced in the body in two forms, Low-Density-Lipoprotein cholesterol (LDL) and High-Density-Lipoprotein cholesterol (HDL). LDL is considered unhealthy because it helps in building plaques within the walls of arteries. HDL is healthy as it helps in lowering LDL and also dissolves LDL formed within arteries. Although major portion of body cholesterol is produced within the body, some portion of it is also added by the diet consumed. High risk of coronary heart disease exists in people with high fat content. Coronary heart disease is caused by accumulation of fat, cholesterol, calcium and fibrin (Coronary Artery Disease, 2009). Obesity and cardiac disease have been evidenced in most of the cases and has been proven through innumerable researches in the last century. Regional distribution of fat is associated with high incidence of cardiovascular diseases and mortality. Després et al’s (1990) review specifically focused on mechanism by which regional distribution of body fat causes high risk of cardiovascular diseases than overall obesity or related symptoms. High body fat content increases metabolic dysfunctions such as insulin resistance, hyperinsulinemia, glucose intolerance, and type II diabetes mellitus. This review specifically focused on metabolic complications of lipoprotein metabolism which is essential to create a balance between LDL and HDL cholesterol. Other epidemiological researches included in Després et al.’s (1990) review identified that high proportion of abdominal obesity had increased probability of cardiac disease. Several investigators reported that fat topography was associated with plasma insulin levels and with plasma glucose and insulin responses to a glucose tolerance test. This review by Després et al (1990) also indicated associations between body fat localization and hypertension. Accumulation of abdominal fat had more detrimental effects on blood pressure than peripheral fat accumulation. Dysfunctional glucose homeostasis caused due in chronic stress conditions or unhealthy eating habits have increased susceptibility to diabetes and hypertension. Excessive deposition of abdominal fat decreases HDL cholesterol. The review also established a relationship between body fat distribution and metabolic dysfunctions, with higher inclination towards functioning of heart and its vessels. Specific dietary fatty acids and cholesterol are also linked to incidence of cardiovascular diseases in men and women. Specifically in women with Type 2 Diabetes, change of diet from saturated fat to monosaturated fat lowered risk of Cardiac diseases compared to replacement with carbohydrates according to studies carried out by Tanasescu et al. (2004). In these studies, metabolic functionalities were noted which indicated exchanging saturated fat for carbohydrates increases both LDL and HDL cholesterol, whereas exchanging monosaturated and polyunsaturated fat for saturated fat lowers LDL cholesterol. It was noted that monosaturated fat did not lower HDL cholesterol when used to replace saturated fat; however, the studies could not establish the role of polyunsaturated fat. These metabolic studies indicated that saturated fat impaired insulin sensitivity, whereas diets with larger quantities of unsaturated fat improved glucose metabolism. Replacement of saturated fat with monosaturated fat directly improves lipoprotein and glycemic control in patients with type 2 diabetes. Marckmann et al’s (1994) research on similar lines, i.e. sample population tested on low-fat diet and high-fat diet indicated that low-fat diet lowered the serum concentration of LDL, HDL cholesterol and fasting triglycerides; this research was also extended to test coagulant activity of plasma factor VII, which indicated reduction in thrombogenic activity too. Risk factors: Potential risk factors for cardiac disease are obesity, diabetes, smoking, and inactivity. High amounts of triglycerides, high blood pressure, low HDL, insulin resistance may also become the cause for different types of cardiac diseases. Food items like fatty meat and whole fat dairy products, snack foods, oil, read-to-eat foods are rich in saturated fats. Other food items with high dietary cholesterol are egg yolks, organ meats, shrimp, squid, and fatty meats (Living with Cholesterol, n.d). Inactivity and lethargy also increase cholesterol levels in the blood. The food consumed needs to be digested well in order to get dissolved in blood. Larger quantities of food or food rich in saturated fats tend to convert to body fat which gets deposited. This deposited fat melts only with excessive body activity. Lack of activity accumulates more and more fat, and this fat converted to LDL remains in the blood. Accumulation of LDL in larger quantities causes plaque formation in the heart vessels and other passages, causing cardiac diseases such as atherosclerosis. Therefore, lack of exercise is also a major contributor to heart diseases, especially if the diet contains saturated fat. Increased blood sugar and blood pressure levels may also cause heart diseases. Both these conditions are again associated with fat and cholesterol to some extent. Increased LDL has been associated with insulin resistance, thereby causing increased blood sugar levels. Cardiac disease in such cases is usually preceded by diabetic conditions. In other words, diabetic patients have high risk of cardiac diseases. Treatment and Management: Treatment of all types of cardiac diseases is possible through surgical intervention and/or medication if diagnosed early. Management post treatment and even prevention involves diet therapy along with exercise as a major regime (Weisse, 2002). Prevention of heart disease may also be done by providing supplements of magnesium. Diet rich in magnesium helps in lowering the risk in the longer run. This helps in controlling the blood pressure, in addition to other medications in lowering cholesterol, and other therapies (Kelly, 2000). Detection of potential cardiovascular disease requires assessment of serum cholesterol, hypertension, diabetes, ECG-LVH, and intensity of cigarette smoking, and LDL and HDL cholesterol levels. Risk of CVD becomes much higher if accompanied by other risk factors, like, high cholesterol levels along with diabetes and hypertension. Control of blood pressure can cut risk of cardiac disease to a great extent. This can be done by exercise, meditation and healthy diet (Weisse, 2002). Conclusions: In conclusion, the type of fat and cholesterol significantly impact cardiovascular health along with mental wellbeing of the individual. With changing lifestyles and increasing economic status, people who seek easily available foods tend to ignore the associated after effects of these foods. Extensive researches have established that obesity caused due to intake of unhealthy food, i.e. food rich in saturated fats and carbohydrates, and cardiac diseases are strongly related; however, obesity may or may not directly lead to cardiovascular disease. Intermittent conditions such as hypertension, diabetes, metabolic dysfunctions of lipid proteins (LDL and HDL cholesterol), anxiety disorders and chronic stress disorders usually precede cardiac diseases. For this reason treatment and management of cardiac diseases includes comprehensive regimen to counter the associated medical conditions also. Prevention of cardiac disease can be achieved to a large extent by preventing risks of hypertension, obesity, diabetes, and other related conditions by adopting healthy life styles including healthy eating habits and a systematic physical exercise regimen. Along with reduction in risk of cardiac disease, these regimens will also help in building healthy mental status, thus preventing chronic stress conditions which will further lower risk of cardiac disease. References Howson, C.P. (1998). Control of cardiovascular diseases in developing countries: research, development, and institutional strengthening. Washington D.C: National Academies Press. http://books.google.co.in/books?id=DpmGdkexmk4C&pg=PA1&dq=cardiac+disease#v=onepage&q=cardiac%20disease&f=false Weisse, A.B. (2002). Heart to heart: the twentieth century battle against cardiac disease : an oral history. U.S.A: Rutgers University Press. http://books.google.co.in/books?id=hrHHbtRI5oIC&printsec=frontcover&dq=cardiac+disease#v=onepage&q=&f=false Journals: Després et al. (1990). Arteriosclerosis, Thrombosis, and Vascular Biology. Regional distribution of body fat, plasma lipoproteins, and cardiovascular disease. Journal of the American Heart Association. Vol 10, No.4 pp:497-511. Accessed November 17, 2009 from www.avb.ahajournals.org Lesman-Leegte et al. (2006). Psychological distress and cardiovascular disease. European Heart Journal. Vol. 27, No.9 p.1123. Accessed November 19, 2009 from, http://eurheartj.oxfordjournals.org/cgi/rapidpdf/ehi798v1 Lichtlen, P.R. (2002). History of coronary heart disease. Vol. 91. No. 4. pp: 56-59. Accessed November 18, 2009 from http://www.dgk.org/organe/geschichte/75years/KAP7.PDF Marckmann et al. (1994). Low-fat, high-fiber diet favorably affects several independent risk markers of ischemic heart disease: observations on blood lipids, coagulation, and fibrinolysis from a trial of middle-aged Danesh. The American Society for Clinical Nutrition, Inc. American Journal of Clinical Nutrition. Vol 59, pp: 935-939. Accessed November 19, 2009 from, http://www.ajcn.org Tanasescu et al. (2004). Dietary fat and cholesterol and the risk of cardiovascular disease among women with type 2 diabetes. American Journal of Clinical Nutrition. Vol: 79. pp: 999-1005. Accessed November 18, 2009 from, http://www.ajcn.org/cgi/reprint/79/6/999 Tafet, G. (2001). Correlation between cortisol level and serotonin uptake in patients with chronic stress and depression. Cognitive, Affective, and Behavioral Neuroscience. Vol.1 No.4. pp: 388-393 Articles Cardiovascular diseases and conditions. (2009). Heart disease. Womentowomen. Last updated September 17, 2009. Accessed November 19, 2009 from, http://www.womentowomen.com/heartdiseaseandstroke/cardiovasculardiseases.aspx Carson-Dewitt, R. (2009). Coronary artery disease (Coronary heart disease). Diseases and Conditions. Mount Sinai Medical Centre. Updated September 2009. Accessed November 19, 2009 from http://www.mountsinai.org/Other/Diseases/Coronary%20artery%20disease Coronary Artery Disease (2009). Heart Information Center. Texas Heart Institute. Accessed November 18, 2009 http://texasheart.org/HIC/Topics/Cond/coronaryarterydisease.cfm Hitti, M. (2004). Heart Disease Kills Every 34 Seconds in U.S. FOXNEWS.COM. November 18, 2009 http://www.foxnews.com/story/0,2933,142436,00.html Kelly, J. (2000). Got Magnesium? Those With Heart Disease Should. WebMD Health News. Updated November 9, 2000. Accessed November 18, 2009 from http://www.webmd.com/news/20001109/got-magnesium-those-with-heart-disease-should Living with Cholesterol (n.d.). Living with Cholesterol: Cholesterol and Healthy Living. Heart and Stroke Foundation. November 18, 2009 www.heartandstroke.ca United States (1999). "Chronic Disease Overview". United States Government. Retrieved November 17, 2009. http://www.cdc.gov/nccdphp/overview_text.htm Read More