The new scientific Dietary Guidelines for Americans reports for the first time ever that avocados contain "good" unsaturated fats that do not raise blood cholesterol and should be included as part of a healthy diet.

"We have always known that avocados are good-tasting," said Johanna Dwyer, professor of Medicine and Community Health at Tufts University School of Medicine.

"Now we know that they are also a part of a healthy diet," said Dwyer, a member of the Dietary Guidelines Advisory Committee.

The Dietary Guidelines 2000 update report, developed by the United States Department of Agriculture and Department of Health and Human Services, and re-issued every five years, was designed to help Americans choose eating patterns that meet nutrient needs, promote health and active lifestyles and reduce chronic disease risks.

The new report suggests a diet based on moderate amounts of foods high in unsaturated fats to help keep blood cholesterol low and offer some protection against heart disease. Avocados contain good sources of unsaturated fats, much like vegetable oils, most nuts, olives and fatty fish like salmon, according to the report.

"With increasing public awareness of its inherent nutritional benefits, the avocado is fast becoming an essential part of a healthy American diet, so we are pleased that it is being recognized as a food that can build a nutritious diet and lifestyle," said Mark Affleck, president of the California Avocado Commission, which serves as the official information source for the California avocado industry.

The Dietary Guidelines urges Americans to choose a diet moderate in total fat and one where most of the calories come from plant foods. While fats supply energy and essential fatty acids, and help absorb fat-soluable vitamins A, D, E and K, they should be chosen sensibly, since eating lots of fat can provide excess calories, the report says.

The new guidelines also implore Americans to aim for a healthy weight, be physically active every day and choose a daily diet of grains, vegetables and fruits in order to stay healthy and fit. The report suggests being more flexible in the choice of fruits, vegetables and grains, and trying new choices from these three groups in place of some less nutritious or higher calorie foods usually eaten.

New to the guidelines is a recommendation to strive to eat a new kind or color of fruits and vegetables and to serve them in new ways, such as raw, stir-fried or mixed with other foods in soups, salads and casseroles. This will form a base of good nutrition and good health and may reduce the risk of certain chronic diseases, according to the report.

The new Dietary Guidelines also reports that fiber is best obtained from foods like fruits, vegetables and whole grains rather than from fiber supplements for several reasons: there are many types of fiber, the composition of fiber is poorly understood, and other protective substances accompany fiber in foods. The reports say that folate (folic acid) is a B vitamin that reduces the risk of serious types of birth defects and may also help protect against coronary heart disease and possibly certain cancers. Folate and fiber are higher in avocados than any other of the top 20 fruits by Americans.