Prevention begins with knowledge. By understanding heart disease and the factors that put you at risk, you can then take steps toward a heart healthy lifestyle. The following are questions and answers about heart disease and its prevention.

Q. What is the most common form of heart disease?

A. The most common form of heart disease is called coronary artery disease (CAD). It is a condition in which the arteries that supply oxygen to the heart become diseased. As plaque and cholesterol build up on the artery walls, blood flow becomes restricted. If the narrowing continues, the risk of heart attack increases.

A: There are a number of major risk factors that can contribute to heart disease. Some of them, such as heredity, cannot be altered. Coronary artery disease and other conditions that increase the odds of heart disease are often inherited. Others such as diet and exercise can be controlled. The primary risk factors are:

• High blood pressure (hypertension)

• High blood cholesterol

• Obesity

• Smoking

• Diabetes

• Heredity

• Physical Inactivity

• Uncontrolled Stress

A: People with diabetes are more likely to develop heart disease because high blood sugar levels can harden and damage the arteries that deliver oxygen to the heart. High blood sugar can also cause higher fat levels in the blood, which can narrow and clog arteries.

A: Chronic stress may increase the risk of heart disease because it can elevate heart rate and blood pressure. Hormones such as adrenaline are also released into the bloodstream during times of stress, which can contribute to a rise in blood pressure.

A: In addition to increasing your risk of cancer and emphysema, smoking is a significant risk factor for heart disease. Smoking tightens major arteries, contributes to high blood pressure and low HDL ("good") cholesterol. Also, the chemical found in tobacco smoke can lead to plaque buildup on artery walls.

A: Cholesterol is a sticky, fatty substance that is produced by the body. Only a small amount of cholesterol is necessary for the production of certain hormones and other vital functions. The body makes all the cholesterol it needs; therefore, it is not necessary to get additional cholesterol from food. If too much cholesterol is present in the bloodstream, the excess is deposited in the arteries leading to narrowing and blockages. If your total cholesterol level is between 200-239 mg/dL, you are considered to be at borderline high risk. Levels of 240 mg/dL or more are high. The desirable level is under 200 mg/dL.

A: LDL, or low density lipoprotein, carries fats and cholesterol in the bloodstream. LDL is known as "bad cholesterol" because high levels are considered a risk factor in the development of coronary artery disease. When too much LDL cholesterol circulates in the blood, it is deposited as plaque in the arteries and slowly builds up. A level of 160 mg/dL is considered high, 130-159 mg/dL is borderline high, and less than 130 mg/dL is desirable. HDL, or high density lipoprotein, also acts to carry cholesterol in the bloodstream. HDL is considered "good cholesterol" because elevated levels are correlated with a lower risk for coronary artery disease. HDL cholesterol is thought to carry cholesterol away from the arteries, slowing the buildup of plaque. Low levels of "good cholesterol" less than 35 mg/dL, are considered a risk factor for heart disease. High levels, over 60 mg/dL reduce the risk of heart disease.

Q. What are triglycerides and what role do they play in heart disease?
A: Triglycerides are a form of fat found in foods and produced by the liver in the body. They are carried in the blood and stored as body fat. There is an association between high triglycerides and an increased risk of heart disease. Individuals with high triglyceride levels typically have high overall cholesterol levels with high LDL cholesterol and low HDL cholesterol. Triglyceride levels under 150 mg/dL are classified as normal. Borderline high would fall in the range of 150-199 mg/dL. Levels above 200 mg/dL are considered high.

A: From age 20, adults should have a fasting blood cholesterol test every 5 years. The test should include total cholesterol, LDL cholesterol, HDL cholesterol and triglycerides.

A: Diet plays an important role in heart health. The American Heart Association recommends a diet low in total fat, saturated fat and cholesterol for people over two years of age. Fat should make up no more than 30% of the calories consumed and saturated fats should be less than 10% of calories. Limit cholesterol to 300 mg a day or less. The DASH diet (Dietary Approaches to Stop Hypertension) has been found to help reduce or prevent hypertension (high blood pressure), a major risk factor for heart disease. This eating plan suggests a diet rich in fruits, vegetables, low-fat dairy foods, dietary fiber, potassium, calcium and magnesium. It also stresses foods that are low in saturated and total fat; and limits meat, poultry and fish to two servings a day or less.

Total daily intake recommendations are as follows:

• Grains and grain products: 7 to 8 servings daily

• Vegetables: 4 to 5 servings daily

• Fruits: 4 to 5 servings daily

• Low-fat or nonfat dairy products: 2 to 3 servings daily

• Meat, poultry and fish: 2 or less servings daily

• Nuts, seeds and legumes: 1 serving daily

Q. Can exercise reduce my risk of heart disease?

A: Yes, regular aerobic exercise can strengthen the cardiovascular system and reduce the risk of heart disease. Exercise can help control cholesterol, blood pressure, diabetes, obesity and stress. It also reinforces other healthy lifestyle changes such as smoking cessation and eating a balanced diet. Exercising for at least 20 minutes 3-5 times a week is recommended for improving endurance and cardiovascular health. The key is to find an activity the fits your lifestyle and interests. Swimming, jogging, distance walking, dancing and bicycling are popular choices. Cross training, alternating various types of exercise, can improve results and reduce the boredom that can come from repeating the same exercise. Talk to your health care provider before getting started on an exercise program.