Nutritional Contribution of Eggs to American Diets
Won O. Song, PhD, MPH, RD, and Jean M. Kerver, MS, RD
Food and Nutrition Database Research Center, Department of Food Science and Human Nutrition, Michigan State University, East Lansing, Michigan E-mail: song@pilot.msu.edu
Objectives: The main purposes of this study were (1) to assess the nutritional significance of eggs in the American diet and (2) to estimate the degree of association between egg consumption and serum cholesterol concentration.
Methods: Data from the most recent National Health and Nutritional Examination Survey (NHANES III, 1988-94) were utilized to compare the nutritional quality indicators of diets that contained eggs (USDA food grouping system) with those that did not. Nutrient intake (from 24-hour dietary recall), egg intake (from food frequency questionnaire), sociodemographic data and blood cholesterol levels of subjects who met inclusion criteria (n=27,378) were grouped according to the occurrence and frequency of egg consumption and were analyzed using SUDAAN.
Results: Daily nutrient intake of egg consumers (EC) was significantly greater than that of nonconsumers (NC) for all nutrients studied (except dietary fiber and vitamin B6). Eggs contributed < 10% of daily intake of energy and vitamin B6, 10% to 20% of folate and total, saturated and polyunsaturated fat, and 20% to 30% of vitamins A, E and B12 in EC. Compared to EC, NC had higher rates of inadequate intake (defined by Estimated Average Requirements (EAR) or < 70% Recommended Dietary Allowance (RDA)) for vitamin B12 (10% vs. 21%), vitamin A (16% vs. 21%), vitamin E (14% vs. 22%) and vitamin C (15% vs. 20%). After adjusting for demographic (age, gender and ethnicity) and lifestyle (smoking and physical activity) variables, dietary cholesterol was not related to serum cholesterol concentration. People who reported eating 4 eggs/wk had a significantly lower mean serum cholesterol concentration than those who reported eating 1egg/wk (193 mg/dL vs. 197 mg/dL, p < 0.01). More frequent egg consumption was negatively associated with serum cholesterol concentration (beta = -6.45, p < 0.01).
Conclusions: In this cross-sectional and population-based study, egg consumption made important nutritional contributions to the American diet and was not associated with high serum cholesterol concentrations.