Eggs - Good for Your Eyes, Brain, and Heart

The Scientific Evidence that Supports the Health Claim

Apr 20, 2009

In the past, people have been advised to avoid eggs. Now, two hundred twenty four trials show eating 1-2 eggs a day is actually good for you.

Humans have consumed eggs for centuries. Chicken, duck, turkey, quail, guineafowl, pheasant, ostrich, turtle, and other exotic eggs contain the highest quality of protein called biological value protein. (Eggs 100%, Milk 93%, Beef 76%, Fish 75%, and Corn 72%). Biological value protein - is a measure of protein quality.

They are also good sources of selenium, riboflavin, vitamin B12, pantothenic acid, dietary fat, and vitamin D. They contain measurable levels of vitamin A, vitamin B6, zinc, iron, calcium, and vitamin B1.

Health Benefits

Eggs are good sources of Lutein and zeaxanthin - carotenoids that protect human macula from oxidative stress and ultraviolet light. The macula is part of the retina that gives us central vision, thus protecting the eyes from macular degeneration, a leading cause of blindness in people over 65 years of age. Lutein and zeaxanthin from egg yollks are more bioavailable than lutein from plant sources.

Choline - a neurotransmitter and a key component of many fat-containing structures in cell membranes abounds in egg yolks. Choline provides flexibility and integrity to phosphatidylcholine and sphingomylin - 2 fat-like molecules that makes up a large percentage of the brain's mass, making choline critical for brain function and health. As a neurotransmitter, choline carries messages from nerve to nerve, and is the principal chemical messager between muscles and nerves.

Choline has been shown to enhance brain function and boost thinking capacity and memory. Recent studies show that providing additional choline during pregnancy is vital to brain development and heightened memory capabilities throughout life. In adults, it appears to aid in treating memory deficiencies.

In addition, choline and betaine (a derivative of choline) work together in transforming homocysteine into cysteine. Homocysteine is a by-product of normal metabolism that increases heart disease risk by increasing blood clotting and inflammation. Choline and betaine turn off genes involved in inflammation.

In 2003, Cho and his colleagues showed that eating whole eggs may help reduce the risk of stroke and heart attacks by preventing blood clotting. Egg proteins delay human blood clotting and prolong the conversion of fibrinogen to fibrin. Fibrin provides scaffolding for platelets, red and white blood cells to form blood clots. Their study was published in the 2003 issue of Biological and Pharmaceutical Bulletin.

Selection and Storage

Do not wash eggs before refrigerating. This will destroy the egg's protective membrane (cuticle). Refrigerated eggs will stay in good condition for 2 -3 weeks. If freezing eggs is necessary, separate yolks from whites, and freeze them separately.

Warning

Egg whites contain a protein called avidin. It binds the eggs' biotin - a water-soluble vitamin thereby preventing it from absorption. Cooking the egg or egg whites changes avidin making it easier to digest and unable to interfere with biotin absorption.

Eggs are a tasty, nutritious, affordable, widely-available and a wholesome alternative to meat. Easy to prepare, they can become part of a healthy diet.

References

Wenzel AJ et al. "A 12-week egg intervention increases serum zeaxanthin and macular pigment optical densitry in women" Journal of Nutrition October 2006;136(10):2568-2573

Detopoulo P et al. "Choline and Inflammation" Am. J Clin. Nutr. 2008 February;87(2):424-430

Cho HJ et al. "Effects of proteins from hen egg yolk on human platelet aggregation and blood coagulation"

The copyright of the article Eggs - Good for Your Eyes, Brain, and Heart in Food Facts is owned by Alicia Richardson. Permission to republish Eggs - Good for Your Eyes, Brain, and Heart in print or online must be granted by the author in writing.