|What Is an Egg?
An egg is a nutritious food. Eggs provide high-quality protein and a variety of vitamins and minerals. Eggs are relatively low in calories and saturated fat, but their cholesterol content is higher than that of most other foods.
In the Food Guide Pyramid, eggs are part of the group of protein-rich foods, officially known as the "Meat, Poultry, Fish, Dry Beans, Eggs, and Nuts Group." The Pyramid calls for two to three servings from this group every day, for a total of five to seven ounces of meat or its equivalent. One egg can be substituted for one ounce of meat. One egg therefore counts as one-third to one-half of a meat group serving.
What Are the Benefits of Eggs?
Eggs are tasty, nutritious, convenient, useful in recipes, and inexpensive.
One large egg, which represents less than 4 percent of the total daily calorie intake of a person who consumes 2000 calories per day, provides 10 percent of the Daily Value for protein, 15 percent of the Daily Value for riboflavin, and 4 percent or more of the Daily Value for several other nutrients, including vitamins A, B6 and B12; folate; iron; phosphorus; and zinc. Eggs also provide choline, which may be essential in the diet. Because the percentage of the Daily Value for many nutrients provided by an egg is greater than the proportion of total calorie intake that the egg represents, the egg more than pulls its weight nutritionally. Most of the vitamins and minerals in eggs are found in the yolk; protein, however, is found in both the yolk and the white.
Recent research indicates that egg eaters are more likely than non-egg eaters to have diets that provide adequate amounts of essential nutrients. This seems to be partly due to the nutritional contribution of the eggs themselves and partly due to the fact that the inclusion of eggs in the diet is an indicator of a desirable eating pattern that includes breakfast.
Eggs can be prepared easily, in a variety of ways. They keep well on a shelf in the refrigerator for about three weeks, and therefore an individual can easily use up the dozen eggs in a carton before they spoil. Because most egg recipes involve short cooking times, eggs are convenient for the person with little time to prepare meals.
Eggs have several important physical and chemical properties that help make recipes work. They thicken custards, puddings and sauces; emulsify and stabilize mixtures such as mayonnaise and salad dressings; coat or glaze breads and cookies; bind ingredients together in dishes such as meat loaf and lasagna; clarify soups; retard crystallization in boiled candies and frostings; and leaven some types of baked goods such as soufflÅ½s and sponge cakes.
Eggs are economical, especially when compared to other high-protein foods. For people who are trying to balance their budgets as well as their diets, serving eggs occasionally instead of meat, poultry, or fish may be helpful.
One other potential (though not established) benefit of eggs is that they may be a functional food that is, a food that provides health benefits that go beyond basic nutrition. Eggs contain the carotenoids lutein and zeaxanthin, which are being investigated to determine whether they have health benefits.
What Are the Charges Leveled Against Eggs?
Eggs are high in cholesterol. They are, in fact, the largest single source of cholesterol among the foods commonly eaten in the U.S. All of the cholesterol in an egg is in the egg yolk, not the white.
For more than 20 years, Americans were advised to strictly limit their intake of egg yolks to three or four a week. Recently, in response to research findings indicating that the effect of dietary cholesterol on blood cholesterol is much smaller than the effect of saturated fat, experts have stopped recommending a specific limit to the number of egg yolks consumed per week but have instead advised people to use eggs in moderation as part of a diet that meets the established guidelines for saturated fat and cholesterol intake. Some people have objected to the relaxation of the limits on egg intake on the grounds that 1) eggs are often eaten with foods high in both saturated fat and cholesterol, such as bacon or sausage; and 2) the usual serving size of eggs is two rather than one, and the cholesterol content of two eggs exceeds the recommended daily limit.
Concerns have also been raised about the microbiological safety of eggs. About 1 in 20,000 eggs is contaminated with Salmonella, a bacteriium that can cause illness. According to the U.S. Department of Agriculture, about 2.3 million contaminated eggs are produced in the U.S. each year and about 100,000 to 150,000 cases of foodborne illness are caused each year by Salmonella in shell eggs.
What Are the Facts?
Extensive scientific research, including major studies completed within the last few years, shows that dietary cholesterol has only a small effect on blood cholesterol and that little if any relationship exists between egg consumption and heart disease risk in healthy people. Several studies have indicated that heart disease risk is no higher among healthy people who eat eggs regularly (up to an intake of about an egg a day) than among those who rarely or never eat them.
This does not mean, however, that an egg a day is acceptable for everyone. The recommendation to limit cholesterol intake to an average of 300 mg/day is still in effect. An egg a day fits within this limitation only if the individual's overall diet is otherwise low in cholesterol.
The idea that consumption of eggs should be discouraged because eggs are often eaten with bacon or sausage doesn't really make sense. Condemning eggs for the company that they kept in old-fashioned breakfasts is no more appropriate than condemning bread because people might put butter on it. Eggs (and bread!) can just as easily be served in other ways that are more suitable to a heart-healthy diet.
The fact that people often eat two eggs at a meal rather than one also is not a valid argument against inclusion of eggs in the diet. It is not necessary for individuals to keep their cholesterol intake under 300 mg/day every single day. Instead, this is an average to be achieved over a period of several days. Having a two-egg meal on one day is fine, as long as it is balanced out by a low-cholesterol meal on another day, so that cholesterol intake stays under an average of 300 mg/day over a several-day period. It's also important to remember that even though eggs are cholesterol-rich, they account for only about 1/3 of the cholesterol in the typical American diet.
The presence of Salmonella bacteria in a small proportion of the eggs on the market need not be a problem if the eggs are handled and prepared properly. Adequate cooking destroys Salmonella and makes the eggs safe to eat.
All packages of shell eggs sold in the U.S. (except pasteurized eggs) now carry the following label statement:
SAFE HANDLING INSTRUCTIONS:
To prevent illness from bacteria: keep eggs refrigerated, cook eggs until yolks are firm, and cook foods containing eggs thoroughly.
Consumers should be careful to follow these safe handling instructions.
Recent coordinated efforts to improve food safety in the U.S. appear to have resulted in a decrease in foodborne illnesses, including the type associated with Salmonella in eggs. Despite this improvement, however, all authorities recommend that people should continue to refrain from consuming raw or undercooked eggs.
The Bottom Line
A person's entire diet, not any single component, is what is crucial for good nutrition. There are bad diets, but there is no such thing as a bad food (unless the food is spoiled or contaminated). Moderate amounts of any food can be incorporated into a balanced, nutritious diet. Excessive consumption of eggs like excessive consumption of any food is unwise. For most people, however, the avoidance of eggs is also undesirable and unnecessary. It limits variety in the diet and keeps people from taking advantage of the benefits of eggs, including their high nutrient content, low cost, convenience, and usefulness in recipes. Excessively strong advice to minimize the use of eggs may be especially detrimental to people with limited incomes, who need low-cost protein foods, and to elderly people, for whom the high nutritional value, low cost, ease of preparation, and ease of chewing of eggs are important advantages.
As with all perishable foods, eggs need to be handled and prepared with care to ensure their microbiological safety. Consumers should be careful to always store eggs under refrigeration and to cook eggs thoroughly.
What's The Story? Eggs
By ACSH Staff — January 1, 2002
By ACSH Staff