According to the American Heart Association, coronary heart disease was the leading cause of death in the U.S. in 2006, claiming over 400,000 lives. Although many factors, including genetics and physical inactivity, lead to susceptibility, it has long been recognized that diet is also important. Understanding the link between diet and heart disease is vital, so that certain foods can be reduced or eliminated from the diet and others encouraged, especially for individuals predisposed to heart disease.
Significance of Diet
Several studies list diet as one of the key contributors to heart disease. This is due to its association with many of the major risk factors linked to the disease, such as high blood pressure, high cholesterol, obesity and diabetes. Individuals who present with one or all of these major risk factors are often encouraged to improve their diet in an attempt to reduce their risk of heart disease. However, a healthy diet should be encouraged even before symptoms become apparent.
Low-Density Lipoprotein Cholesterol
A major breakthrough in the understanding of heart disease was establishing a link between diet, cholesterol metabolism and heart disease. Cholesterol is an essential component of cell membranes. It is also required in the synthesis of many of the body's necessary compounds, such as bile acids, steroid hormones and vitamins A, D, E and K.
Cholesterol is ingested as a component of animal fat, but the majority of cholesterol in the body is synthesized by the liver, adrenal glands, intestines and reproductive organs. Cholesterol is transported through the blood stream by lipoproteins, of which there are many, but high levels of low-density lipoprotein, or LDL, have been linked with cardiovascular disease. Levels of LDL cholesterol are known to increase with a high-fat diet, meaning a diet low in fat is recommended to avoid heart complications.
Heart-Healthy Foods
In a statement released in 2006, the American Heart Association outlined its recommendations for a diet to reduce the risk of cardiovascular disease. It recommended that individuals should consume a diet rich in fruit and vegetables; grain products, especially those containing whole grains; choose fat-free and low-fat dairy products, legumes, poultry and lean meats; and eat fish, preferably oily fish, at least twice a week. They also recommended minimizing the intake of foods and beverages with added sugar, choosing foods with little or no salt and consuming alcohol in moderation.
Foods to Avoid
The foods to avoid in maintaining a healthy heart are those that contain saturated fat and trans fat. The American Heart Association recommends limiting the intake of saturated fat to less than 7 percent of recommended daily calorie intake and trans fat to below 1 percent. Saturated fat can be found in high fat dairy products, such as cream, butter and cheese, and in fatty cuts of meat and meat products. Trans fat is typically found in commercially produced baked and fried goods.
Dietary Supplements and Heart Disease
Many dietary supplements have been tested to treat and prevent the onset of cardiovascular disease. These include carotenoids, folic acid, vitamin D and vitamin E. According to Alice Lichtenstein in a review published in 2008 in the "Journal of Lipid Research," there is insufficient data to support the use of dietary supplements to prevent or treat cardiovascular disease. This review also states that some studies have shown unexpected, adverse consequences as a result of supplementation. It is always advisable to consult a physician before beginning a course of supplements.
References
- American Heart Association
- "Circulation"; Diet and lifestyle recommendations revision 2006: a scientific statement from the American Heart Association Nutrition Committee; AH Lichtenstein et al; 2006
- "Journal of the American College of Nutrition"; The LDL to HDL cholesterol ratio as a valuable tool to evaluate coronary heart disease risk; ML Fernandez and D Webb; 2008
- "Journal of Lipid Research"; Nutrient supplements and cardiovascular disease: a heartbreaking story; AH Lichtenstein; 2008
