Background: The Western lifestyle contributes significantly to the high prevalence of coronary artery disease in Western nations. Smoking, a fat-loaded diet, low physical activity, obesity, diabetes, increased alcohol consumption contribute in a variable combination to the incidence and progression of coronary artery disease. The conventional risk factors are responsible for > 80% of cardiovascular events. Coronary artery disease is therefore a highly preventable disease. Randomized studies evaluating changes and lifestyle are difficult to conduct. Lifestyle is in many respects not governed by the intellect but the result of education, life long habits and possibly also genetically determined. Nevertheless, there is increasing evidence that modification of life style has a significant influence on the incidence and the course of coronary artery disease.
Smoking: Smoking is responsible for 50% of all avoidable death. There is a significant relation between the number of smoked cigarettes and the increase of cardiovascular risk. Despite the lack of randomized end point studies there is universal agreement that the advise for smoking cessation is a class-1-recommendation.
Nutrition: Prospective studies on different components and principles of nutrition (Western vs. Mediterranean diet) demonstrate a significant influence of the diet on the development of coronary artery disease and sudden death. Several randomized studies show evidence that consumption of fish or a Mediterranean diet have a significant influence on the improvement of prognosis.
Weight: There is a correlation between weight and cardiovascular disease and cardiovascular death. A body mass index of > 30 doubles the incidence of sudden death. A moderate increase of body mass index quadruples the risk for diabetes in males, in females the risk is 8-fold increased. Weight reduction improves endothelial function and decreases systemic inflammatory reaction.
Physical activity: There is a significant inverse relation between physical fitness or habitual physical activity on the one hand, and the incidence of coronary artery disease on the other hand. Physical activity improves exercise capacity, decreases angina pectoris and decreases cardiac events and hospital admissions after PTCA. Physical activity also decreases insulin resistance and delays the occurrence of diabetes.
Alcohol consumption: Moderate alcohol consumption was associated with a decrease of cardiovascular events in patients with increased cardiovascular risk. Nevertheless, alcohol consumption in the population is a significant source for avoidable premature death.
Conclusion: The knowledge resulting from observational studies on the importance of lifestyle for the development of coronary artery disease is increasingly validated by prospective randomized studies. Despite the fact that much more research needs to be done the recommendation for improvement of lifestyle in terms of increasing physical activity decreasing overweight, using a Mediterranean diet and smoking cessation are class-1-recommendations. A nationwide improvement in lifestyle could result in a significant decrease in health care expenditures and could also have an important role in preventing or delaying coronary artery disease.