The Incredible, Edible Egg
Dale Petersen MD – Building Health
When I’m asked what foods people should include in their diets the humble egg always tops my list. I give it that spot not only for what it offers, but because it has been so unjustifiably maligned over the past thirty-five years. Old school nutritionists still hold to the belief that a healthy diet can include no more than two eggs per week from any source.
The much maligned egg is one of the most complete food sources available. When I consider that the yolk (ironically, the part most vilified by dietitians) provides all of the building blocks required to produce a living, breathing, walking chick I am awestruck. It is almost unbelievable that all of the needed chemical energy, all of the necessary proteins, vitamins, and minerals for the development of the chick’s bones, internal organs, muscles, and feathers are contained within a single egg yolk.
An egg contains all nine essential amino acids, the protein building blocks that we cannot manufacture and must obtain from external sources. One measure of dietary protein is called its biological value, which refers to how efficiently it can be used to grow and repair muscle, skin, and other body tissues. Biological value also takes into account the importance of the protein in the manufacturing of vital compounds including antibodies, hormones, and enzymes. Egg protein ranks first in biological value, surpassing that of milk, fish, meat, and legumes. As such, nutritional scientists use egg protein as the standard by which all others are measured.
Eggs provide a broad range of vitamins and minerals, but several important egg nutrients are often overlooked. Two of these are the carotinoids lutein and zeaxanthin that have been shown to prevent macular degeneration, the most common cause of blindness in people over the age of fifty. Because these nutrients are fat soluble, the fats naturally accompanying them in eggs make them more highly absorbable than those in vegetable sources such as carrots and spinach. Two-thirds of the fats found in eggs are polyunsaturated and monounsaturated, which are often deficient in American diets.
“But what about cholesterol?” many people ask. “Aren’t egg yolks high in cholesterol?” Yes, egg yolks contain cholesterol, but cholesterol obtained from foods has almost no effect upon blood cholesterol levels. Blood cholesterol levels are determined primarily by the amount of cholesterol manufactured by the liver, not by that absorbed from the digestive tract.
Because the fat contained in eggs is predominantly unsaturated, evidence is now suggesting that including eggs in one’s diet may actually result in improved LDL/HDL cholesterol ratios. (The ratio of LDL to HDL cholesterol is the most significant factor in determining whether or not an individual is at increased risk for atherosclerosis on the basis of cholesterol.)
Another nutrient found in egg yolk may be even more significant in preventing atherosclerosis. Egg yolk is the richest dietary source of a chemical called lecithin. Lecithin is a rich source of choline, which is needed for the production of acetylcholine. Acetylcholine is a chemical that transmits messages between nerve cells. Acetylcholine is critical to learning and memory. Choline is also needed for the manufacture of phosphatidyl choline, a component of cell membranes. Phosphatidyl choline and similar phospholipids have been shown to prevent gallstones by keeping cholesterol in solution rather than allowing it to assume a solid consistency. Liquid cholesterol is never a problem. Only when it solidifies as gallstones or as arterial plaque does it present a challenge. Maintaining cholesterol in solution is one of the primary benefits of including sources of lecithin in the diet. When an adequate amount of lecithin is consumed, the melting point of cholesterol is lowered from 180 degrees, nearly double body temperature, to 60 degrees, well below normal body temperature.
Given all of these health benefits, it’s ironic that yokeless egg substitutes are often promoted as a healthy option on restaurant menus. The next time you’re tempted to have fried eggs or an omelet, don’t feel guilty. Enjoy your meal knowing that you’re giving your body one of the most nutritious and health-promoting foods available.
Dr. Dale Peterson is a graduate of the University of Minnesota College of Medicine. He completed his residency in FamilyMedicine at the University of Oklahoma. He is a past president of the Oklahoma Academy of Family Physicians. He had a full-time family practice in Edmond, Oklahoma, for over 20 years and was a Chief of Staff of the Edmond Hospital. He was active in teachingfor many years as a Clinical Professor of Family Medicine through the Oklahoma University Health Sciences Center.
Dr. Peterson left his full-time family practice in 1999 to consult with individuals who are seeking ways to restore and maintain their health through improved nutrition and other lifestyle changes. He founded the Wellness Clubs of America to give people access to credible information on supporting and maintaining their health. His monthly wellness letter, Health by Design, and his Health by Design E-Newsletter provide helpful information to individuals interested in preventing and conquering health challenges. His book Building Health by Design: Adding Life to Your Years and Years to Your Life was released in December 2010.
Dr. Peterson speaks regularly on subjects related to health and nutrition. He hosted a weekly radio program,Your Health Matters, on KTOK in Oklahoma City for five years. For the past nine years he has addressed questions from across the nation on his Your Health Matters weekly teleconference.He offers a free video LifeXtension course at www.drdalepeterson.com.