American Heart Association Dietary Guidelines

The American Heart Association periodically revises its dietary guidelines based on new scientific information as it becomes available. The guidelines, based on an analysis of hundreds of studies, were expanded in 2000 to include specific recommendations tailored to an individual's risk of heart disease and stroke. They were published in Circulation: Journal of the American Heart Association.

Theodore A. Kotchen, MD, Professor of Medicine and Associate Dean for Clinical Research at the Medical College of Wisconsin, is a former member of the AHA's nutrition committee. The four main goals of the new guidelines, he says, are 1) to help Americans achieve an overall healthy eating pattern; 2) achieve and maintain an appropriate body weight; 3) achieve and maintain a desirable cholesterol profile; and 4) achieve and maintain a desirable blood pressure level.

"Obesity, diabetes, elevated serum cholesterol and hypertension are well-recognized risk factors for cardiovascular disease," Dr. Kotchen says. "By favorably affecting these risk factors, adopting healthy eating patterns can reduce the incidence of heart disease and stroke."

Guidelines are Based on Foods, Not Percentages
For the first time, the guidelines stress the importance of preventing obesity. They are easier for most people to use because they stress overall eating patterns, rather than a percentage of dietary fat or other nutrients.

"We are emphasizing the positive message of what people should eat – for example, more plant-based foods," says Ronald M. Krauss, MD, the principal author of the guidelines and a senior scientist at the Lawrence Berkeley National Laboratory at the University of California. "In the past we have focused rather heavily on the percent of calories as fat and amounts of cholesterol. These are still important considerations, but the emphasis has shifted to allow consumers to understand the importance of an overall eating plan.

Varied Diet Includes Fruits, Vegetables, Grains, Fish
A diet rich in fruits, vegetables, legumes (beans), whole grains, low-fat dairy products, fish, lean meats and poultry is still the basis of the recommendations. The association continues to recommend eating five servings of fruits and vegetables and six servings of grains daily. But, for the first time, two weekly servings of fatty fish, such as tuna or salmon, are recommended.

The guidelines recommend that healthy adults minimize the intake of foods containing high levels of saturated fats (found in animal products and tropical oils) and substantially reduce the intake of trans fatty acids (the hydrogenated oil found in commercially prepared foods and some hard margarines). For people with risk factors for heart disease or those who already have heart disease, further reduction in saturated fat intake is recommended.

The recommended intakes of salt (less than 6 grams per day, or 2,400 mg of sodium) and dietary cholesterol (300 mg/day for healthy individuals, and 200 mg per day for high-risk individuals) remain unchanged.

People who choose to consume alcohol should generally limit themselves to one drink a day for women and two drinks a day for men. People who do not normally drink alcohol should not begin drinking.

The association still recommends that individuals get their nutrients from foods, not supplements.

Targeting High-Risk Populations
The AHA guidelines offer a framework to assist health care providers in tailoring specific medical nutrition therapy to meet the needs of individuals with high blood pressure, cholesterol disorders, diabetes, insulin resistance, high triglycerides, congestive heart failure, kidney disease and/or obesity.

Dr. Krauss says that for individuals with high blood pressure, losing just 5% to 10% of body weight can significantly improve blood pressure. This goal is reachable for many overweight individuals, he says. "In addition, consuming a diet rich in fruits, vegetables, low-fat dairy products and limiting salt and alcohol has been shown in a large study to have major benefits in controlling blood pressure levels."

In recent years, scientists have been studying people who have a cluster of metabolic risk factors for heart disease and/or stroke – excessive fat tissue in the abdominal region, glucose intolerance or diabetes, high blood pressure, and high levels of triglycerides (more than 200 mg/dL). This cluster of risk factors is sometimes called "Syndrome X."

For individuals diagnosed with Syndrome X, it may be desirable to avoid very low-fat, high carbohydrate diets, and to emphasize unsaturated fats, such as vegetable oils and seed oils (excluding tropical oils), rather than carbohydrates. Very low-fat diets (less than 15% to 20% of total calories from fat) with correspondingly high carbohydrate content can lower "good" cholesterol.

Heart Healthy Diet Also Helps Prevent Obesity
"Americans are eating too many calories, and are not getting much nutritional value from those calories," says Dr. Krauss. "Although the guidelines were developed to reduce or delay heart disease and stroke, Americans who follow them could reap many other benefits. Research indicates these nutritional steps could also decrease the risk of developing cancer or osteoporosis."

For obese individuals, the guidelines recommend a weight loss of no more than one to two pounds per week. "Simply put, to lose weight, you must eat fewer calories than you burn and increase physical activity, such as brisk walking, to at least 30 minutes daily."

In addition, people consume many foods that are not "nutrient dense" which often have a lot of added sugars in them, such as sugary soft drinks and commercially-baked goods.

Given the difficulty many people experience in trying to maintain a weight loss over time (especially those between 25 and 45 years), the guidelines recommend efforts to prevent weight gain in the first place. "It is best if people reduce their caloric intake by following our guidelines for healthy adults – a diet rich in fruits, vegetables, low-fat dairy products, and leaner cuts of meat eaten in smaller portions," says Dr. Krauss.

"Americans still need to limit saturated fats and cholesterol, but if they follow the new dietary guidelines, they will be consuming a balanced diet rich in nutrients, and may not need to calculate percentages or amounts of specific dietary components," says Dr. Krauss. "When people eat out, it's hard to think about what percentage of the dinner comes from saturated fat. It's much easier to think about the various food groups."

MCW Health News presents up-to-date information on patient care and medical research by the physicians of the Medical College of Wisconsin.