New developments in health and nutritional function promoted by chicken eggs

Abstract

Japan is one of the top consumer countries in the world of chicken eggs at almost one egg per person per day. Chicken eggs contain eight essential amino acids in an ideal balance, giving an amino acid score that is as high as that for milk and beef (100) and the biological value that exceeds that of the latter foods (94). Furthermore, among animal-source foods, eggs are relatively rich in unsaturated fatty acids, fat-soluble vitamins and minerals such as phosphorus, calcium and iron. Despite these beneficial attributes, many consumers are worried about the relationship between chicken egg consumption and heart disease since chicken eggs are a high cholesterol food. Human studies in Japan reveal that consumption of egg yolk for 4 weeks did not result in an elevation of serum cholesterol level and there was no direct relationship between frequency of egg consumption and a risk of myocardial infarction in a 10-year follow-up study of 90,000 Japanese subjects. Rat studies provide evidence of the hypocholesterolemic action of egg yolk phospholipids and egg white proteins. Furthermore, feeding egg yolk phospholipids to rats with brain injuries and senescence-accelerated mice resulted in enhanced learning ability. These results indicate that chicken egg is an attractive food from the aspects of health promotion and nutritional function.