The egg was once blamed for a variety of health issues but times have changed.
Beyond excellent nutritive value, the table egg possesses several health promoting, antioxidant, immunomodulating, therapeutic and functional properties.
Egg albumen can be used as an antidote in cases where certain toxins and irritants may have been accidentally consumed. It protects the mucous membranes of the stomach and intestine, and prevents ulcer formation.
Egg yolk and albumen chalaza are rich sources of “sialic acid,” mainly Neu-5-Ac, which has been patented and is sold as “Slex” in some countries. It has powerful antimicrobial, anti-inflammatory and antiviral properties, and hence is used in the treatment of Helicobacter pylori and other microbial infections causing ulcers, colon cancer, gastritis and enteritis.
Unlike milk, meat, fruits, vegetables and other high-moisture foods, eggs can be stored at room temperature for up to four weeks, as their lysozyme, ovomacroglobulin and other components possess antimicrobial properties, which prevent the microbial spoilage of eggs. This allows eggs to be used as natural and safe antimicrobial agents.
Due to their water holding and binding properties, eggs can counteract the enteritis caused by several toxic substances and microbes, hence the egg white is a good natural remedy for gastritis, enteritis, diarrhoea, dysentery and dehydration.
In the case of cuts and burns, insect bites and rashes, the application of egg white, especially chalaza, followed by the pasting of egg shell membrane over the affected skin, can reduce inflammation and infection and help to speed up recovery of wounds and ulcers.
Anti-carcinogenic properties
Studies carried out at Japan’s Kyoto University have revealed that eggs contain the two substances Lumiflavin and Lumichrome.
The two substances, along with Sulphoraphane, are capable of restraining the multiplication of cancer-inducing viruses and also prevent normal cells turning into cancerous cells. These compounds are also natural antioxidants.
Antioxidant properties
The carotenoid pigments present in the egg yolk serve as natural antioxidants as they eliminate free radicals and are anti-carcinogenic agents. These natural pigments are also seen as the precursors of Vitamin A.
They also reduce serum LDL cholesterol (bad cholesterol) and thereby help to prevent cardiovascular disease (CVD).
The egg yolk protein Phosvitin is a potent natural antioxidant, which is safer than synthetic antioxidants. Ethanol-extracted yolk lipid has shown antioxiditative effects on Dicosa Hexa Enoic Acid (DHA), an omega-3 fatty acid, which undergoes rancidity quickly. It also prevents premature ageing.
Vitamin E, organic selenium and other antioxidants in functional eggs prevent oxidation, ageing, formation of plaques in arteries, atheroscelerosis and CVD.
Immunomodulating properties
Eggs possess health promoting and functional properties.
The G1-globulin lysozyme, the G2 and G3-globulins, ovomacroglobulin, antibody “IgY” as well as other natural antimicrobials and immunostimulants in the egg may prolong the lives of those with Aids, not only due to their high nutritional value but also because of their antimicrobial properties.
The egg is the cheapest and best medium for immunoglobulin and vaccine production.
India’s Vittal Mallya Scientific Research Foundation has produced antivenin using chicken eggs and, compared with antivenin produced from horse serum, it is 100 times cheaper.
Functional properties
Intralipid, a parenteral fat emulsion prepared from egg yolk, is used as a carrier of fat soluble drugs. Lecithin from egg yolk is more stable and has higher entrapment efficiency than soy lecithin, and the toxicity of diamidine and other drugs used against protozoal diseases has been found to be lower when encapsulated in egg yolk protein.
The egg yolk lipoprotein YLP- p17.5 promotes the growth of several types of mammalian cells, including human hepatic cells and hybridoma cells. It is used in media for the growth of cells in biotechnology and genetic engineering experiments.
Therapeutic properties
The egg yolk phospholipid lecithin-conjugated with Vitamin B, when given to rats, premature babies and to those with Alzheimer’s disease, results in better nervous tissue development and mental ability.
Chicken eggs are abundant in antibodies such as IgY. Over a six-week period, a hen produces some 289mg of specific antibodies. IgY can treat human rotavirus, Escherichia coli, streptococcus, pseudomonas, staphylococcus and salmonella infections.
The anti-inflammatory, healing, binding, antimicrobial and immunogenic properties of eggs have been recognised by the Indian medicine systems Ayurveda and Sidda for thousands of years.
Eggs are mixed with herbs and used for burns and fractures to accelerate the healing process, while a combination of eggs, herbs, sesame oil and green mung bean paste is applied over fractures prior to application of a plaster of Paris bandage, again to promote the healing of bones.
Growth promoter
The nutritionally balanced, high biological value of the egg is an excellent growth promoter in children. It is the best natural nutritional support for convalescents, especially those with tuberculosis or Aids-related infections. Lipoprotein and other high biological value proteins in the egg act as excellent growth promoters in children and animals.
Cardio-protective properties
Research has shown there is no significant correlation between dietary and serum cholesterol and the body can synthesise its requirement of cholesterol, yet consumers restrict their consumption of cholesterol-rich foods, including eggs. In fact, eggs have cardio-protective properties.
The taurine in eggs, milk and meat prevents atherosclerotic plaque formation in the artieries, helping prevent CVD. Taurine also helps to protect the retina from macular degeneration and retinitis pigmentosa. Conjugated linoleic acid in egg yolk reduces the risk of certain heart and cancer problems.
High levels of homocysteine in the blood is an independent risk factor of CVD. It acts as a powerful molecular abrasive, scraping the mucosa of blood vessels, leading to deposition of plaques and CVD. Betaine, a methyl donor present in sugar beet, red wine, eggs, etc, reduces the plasma homocysteine concentration and prevents atherosclerosis, CVD and stroke.
The designer egg is rich in omega-3 fatty acids and carotenoid pigments, Vitamin E, organic selenium and chromium. The omega-3 fatty acids reduce hypertension, LDL and VLDL, cholesterol and tryglycerides levels, prevent thrombosis, platelet aggregation, angina, atherosclerosis and stroke. The egg yolk lipid is a rich source of the monounsaturated fatty acid (MUFA) oleic acid, having about 42% of total yolk lipids. Nutritionists say MUFA is more beneficial than polyunsaturated fatty acid.
Professor Devareddy Narahari is emeritus professor of poultry science at the Tamilnadu Veterinary & Animal Sciences University, Chennai, India.
Updated: Jun 29, 2009 This article appeared in Poultry International, March 2009. ©Copyright 2010, All Rights Reserved.