Prevention of Coronary Artery Disease through Diet

Abstract

Our understanding of the potential role of diet in the prevention and risk reduction of coronary artery disease (CAD) has evolved in the past 100 years. Data on trends in food consumption and ecological studies are the early evidences that showed associa‐ tions between prevalence and fat intake across and within countries. The last 50 years of epidemiology and clinical trials have focused on the efficiency of nutritional inter‐ ventions in the prevention of CAD. The original diet-heart hypothesis was very simple: Cholesterol is a constituent of atherosclerotic plaque. This hypothesis was based on the differences in average popu‐ lation serum cholesterol levels and population rates of CAD mortality. The Seven Country study was the first to show that the intake of saturated fat varied considera‐ bly by region and populations, with the greatest intake of saturated fat were found to have the highest serum cholesterol levels. Follow-up studies confirmed that these study groups also had the highest incidence of CAD. Thus, it was thought that there was a direct relation between cholesterol in diet, cholesterol in blood, and cholesterol in the plaque and its clinical complications such as myocardial infarction (MI). These findings stimulated further inquiry to determine whether altering the diet could de‐ crease serum cholesterol levels and, thereby, decrease the incidence of CAD. Nearly all clinical trials in the 1960s, 1970s, and 1980s compared usual diets with those char‐ acterized by low total fat, low saturated fat, low dietary cholesterol, and increased polyunsaturated fats. Actually, these diets did reduce cholesterol levels. However, they did not reduce the incidence of MI and CAD mortality. With accumulating evi‐ dence, we have now moved away from a focus on total fat and cholesterol to the im‐ portance of considering the content of fat and total calories in the diet. In other words, the type of fat, rather than the total or the ratio or balance between the saturated and certain unsaturated fats may be the determinant. Recent meta-analyses of intervention studies confirm the beneficial effects of replacing saturated with polyunsaturated fat‐ ty acid on CAD risk. Additionally, recent studies indicate that dietary patterns consis‐ tent with the traditional Mediterranean-style diets (MedD) with a strong focus on veggies, fruits, fish, whole grain, and olive oil are effective in preventing CAD to a de‐ gree greater than low-fat diets and equal to or greater than the benefit observed in sta‐ tin trials. Recent secondary prevention studies have convincingly demonstrated the © 2015 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. benefit of diets that closely followed the MedD in reducing re-infarction and clinical manifestations of CAD. In conclusion, CAD is still a significant problem and a growing health concern world‐ wide. Although mortality rates from CAD have decreased due to advances in phar‐ macological treatments, the prevalence of cardiovascular risk factors continue to increase. The importance of diet as a key modifiable risk factor in CAD is undisputa‐ ble. Nutritional interventions have proven that a complicated set of many nutrients interact to influence CAD risk. Therefore, recent guidelines consider diet as a whole and combine nutrient and energy recommendations into a healthy pattern that is nu‐ trient dense and energy balanced.