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CHAPTER 1
Eggs as Part of a Healthy Eating Pattern
Rylee T. Ahnen a and Joanne L. Slavin*a
a Department of Food Science and Nutrition, University of Minnesota, 166 FSCN, 1334 Eckles Ave, St. Paul, MN 55408, USA
*E-mail:
[email protected] The historical recommendations for egg consumption have been confusing to consumers and have resulted in many individuals wondering whether or not eggs should be considered part of a healthful diet. This chapter is a review of the dietary recommendations concerning eggs, the research that eventually changed those recommendations, and the positive health benefits of incorporating eggs into the diet. Eggs as a source of high-quality protein, as a source of choline, and as a tool for satiety and weight management are each discussed, as is potential for additional improvement of the nutrient profile of eggs through fortification. While additional research may be needed to further demonstrate the association between eggs and certain positive health outcomes, the body of scientific evidence surrounding eggs supports the belief that they are healthful for human consumers and should be considered part of a healthy dietary pattern.
1.1 Introduction
Eggs have long been regarded for their nutrient density, providing consumers with a high-quality protein source in addition to a wide variety of critical minerals, vitamins, and trace elements. 1 Compared to other significant sources of dietary proteins, eggs provide relatively high levels of folate, biotin, choline, and vitamin A for a relatively small number of calories, and also deliver an impressive combination of amino acids. 2,3 Additionally, eggs serve as an affordable protein and nutrient source. As reported in the Nutrient Rich Foods Index, and again in a review by Iannotti et al. in 2014, eggs are the most affordable protein source in the United States when included as part of a comprehensive food list. 4,5
However, despite the wide acceptance that eggs are an affordable and nutrient-rich food, the American public has been reticent to accept eggs as part of a healthy eating pattern owing to concerns about cholesterol intake. In fact, recent studies examining consumer data from the National Health and Nutrition Examination Survey (NHANES) found that from 2001 to 2012 the overall proportion of the U.S. population who consumed eggs regularly (21–22%; p = 0.311) remained unchanged. 6 Research examining consumer perceptions about eggs and the barriers to their consumption found that egg consumption has declined owing to the perceived association most consumers make between the consumption of eggs and dietary cholesterol. 7,9
While the perception that egg consumption is associated with dietary cholesterol and, therefore, is associated with increased levels of plasma cholesterol has been supported by recommendations put forth by the U.S. government and reputable public health organizations in the past, recent examinations of the body of literature concerning egg consumption suggest that eggs should be considered a healthy part of the diet. In the following sections, we will discuss the history of dietary recommendations that resulted in the long-held belief that egg consumption should be undertaken in moderation, the changes in the American dietary pattern that occurred as a result of those recommendations, several of the potential health benefits associated with eggs that make them a key part of the modern healthy dietary pattern, as well as the potential for eggs to be enriched in order to even better serve as a component of healthy diets.
1.2 Dietary Recommendations Concerning Eggs
1.2.1 Introduction
Dietary recommendations concerning the consumption of eggs have been part of the public's understanding of nutrition for nearly half a century, dating back to the 1968 recommendation from the American Heart Association (AHA) that individuals limit their intake of dietary cholesterol to no more than 300 mg per day in order to reduce their risk of cardiovascular disease (CVD), and that individuals consume no more than three whole eggs per week in order to meet that recommendation. 10 That recommendation created a paradigm shift in the way the American public viewed the consumption of eggs, providing the average consumer with an easy to understand dietary intervention they could undertake in order to improve their lifestyle, and resulted in an overall decline in the per capita consumption of eggs in the years that followed. 11 This recommendation against the consumption of dietary cholesterol, and eggs in particular, persisted for decades.
1.2.2 Dietary Recommendations from 1950 to 2010
Dietary recommendations in the United States took their first form in a report published by the American Heart Association in 1957 that posited, in somewhat uncertain terms, that the changing diet of the average American may have contributed to the increased pathogenesis of atherosclerosis in the United States. 12 As noted by Kritchevsky in The Journal of Nutrition, the American Heart Association released another report four years later in 1961 which focused on dietary fats and their relationship to heart attacks and strokes, putting forth recommendations for dietary modifications that began modeling the current construction of our modern dietary recommendations. 13,14 Seven years later, in 1968, the American Heart Association put forth a report that set the standard for dietary cholesterol and egg consumption that would persist for decades – that Americans should limit dietary cholesterol to no more than 300 mg per day and should not consume more than three egg yolks per week. 10
Less than a decade after the American Heart Association recommended that consumers limit their dietary intake of eggs in order to achieve a dietary pattern that protected them against CVD, the United States government began the process of establishing federally sanctioned dietary guidelines for every United States citizen. The first iteration of these guidelines was created and published in 1977 by the U.S. Senate Select Committee on Nutrition and Human Needs, which mirrored the American Heart Association recommendation of limiting dietary cholesterol to 300 mg per day and suggested that Americans limit their intake of eggs as a means of achieving that goal. 15 Following the publication of the report from the U.S. Select Committee on Nutrition and Human Needs, the federal government took steps to formalize the process of creating and disseminating dietary recommendations to the American public and established the Dietary Guidelines for Americans, which have been issued twice a decade since 1980 and provide citizens of the United States with recommendations for developing a healthful diet.
In 1980, the U.S. Department of Agriculture and the U.S. Department of Health and Human Services published the first edition of the Dietary Guidelines for Americans (DGA). These 1980 guidelines, published as a 19-page pamphlet, provided Americans with seven focus areas for improving their overall health through nutrition. 16 One of these focus areas, “Avoid Too Much Fat, Saturated Fat, and Cholesterol,” encouraged Americans to limit their intake of dietary cholesterol in order to reduce their risk of CVD, and provided eggs as an example of a common food that consumers could moderate in their diet to achieve that goal. Recommendations that encouraged Americans to reduce their dietary cholesterol intake, specifically through a reduction in their consumption of eggs, appeared almost universally in the bidecennial DGA reports published by the federal government up to, and including, the report published in 2010. 17,22 A summary of the dietary recommendations for egg consumption and cholesterol included in each of the Dietary Guidelines reports can be found in Table 1.1.
Table 1.1 Recommendations for egg consumption as a means of regulating dietary cholesterol from the Dietary Guidelines for Americans and its predecessor, the Dietary Goals for the United States
| Year | Source | Recommendation |
| 1977 | Dietary Goals for the United States | “Decrease consumption of butterfat, eggs and other high cholesterol sources.” |
| 1980 | Dietary Guidelines for Americans | “Moderate your use of eggs and organ meats (such as liver).” |
| 1985 | Dietary Guidelines for Americans | “Moderate your use of egg yolks and organ meats.” |
| 1990 | Dietary Guidelines for Americans | “Moderate the use of egg yolks and organ meats.” |
| 1995 | Dietary Guidelines for Americans | “Dietary cholesterol comes from animal sources such as egg yolks, meat (especially organ meats such as liver), poultry, fish, and higher fat milk products. [⋯] Choosing foods with less cholesterol and saturated fat will help lower your blood cholesterol levels.” |
| 2000 | Dietary Guidelines for Americans | “Use egg yolks and whole eggs in moderation. Use egg whites and egg substitutes freely when cooking since they contain no cholesterol and little or no fat.” |
| 2005 | Dietary Guidelines for Americans | No specific recommendation for eggs. |
| 2010 | Dietary Guidelines for Americans | “The major sources of cholesterol in the American diet include eggs and egg mixed dishes (25% of total cholesterol intake) [⋯] Cholesterol intake can be reduced by limiting the consumption of the specific foods that are high in cholesterol.” |
| 2015 | Dietary Guidelines for Americans | “More research is needed regarding the dose–response relationship between dietary cholesterol and blood cholesterol levels. Adequate evidence is not available for a quantitative limit for dietary cholesterol specific to the Dietary Guidelines. Dietary cholesterol is found only in animal foods such as egg yolk, dairy products, shellfish, meats, and poultry.” |
1.2.3 Dietary Reco...
