The Health Value of Eggs

Eggs, Second in ImportanceAs Dietary Factor
Vitamins, Mineral and Proteins areCombined in this Valuable Food.

By Ethel Heaberlin, B. S. Foods and Diet Editor

National egg Week in May reminds us that there is only one food product more essential to health than eggs and that is milk. Strictly vegetarian diets have been proven inadequate to support normal life. Vegetable foods, unless carefully chosen, will not supply sufficient amounts of biologically adequate protein and the fat-soluble vitamins. Milk and eggs, because of the excellence of their proteins, mineral salts and vitamins are valuable in complementing a vegetarian diet without the introduction of meat.

The food value of eggs is high. Experiments have shown that as a suitable food for the young, eggs rank next to milk. McCollum states that eggs contain everything necessary for growth and maintenance of the body but are poor in calcium and lacking in carbohydrates. The yolk is more nutritious than the white since it carries the Vitamins A, D, and E, supplies most of the minerals, and gram for gram, the yolk furnishes 7 times as much energy. Eggs vary in size but, in calculating diets, 6 grams each of protein is 75% water. Entein, a carotin-like pigment, provides the yellow color of the yolk; the depth of the color depends on the feed.

Of all the vitamins, D is most lacking in foods. Although ultra-violet rays of the sun will aid the body in synthesis of Vitamin D on direct exposure, sunshine is not always available. During the long winter months and in the early spring, the inclusion of an egg yolk a day in the diet for the six months old babe to his tottering grandfather will supply well a liberal amount of Vitamin D. McCollum and Davis in 1913 found the fats of the egg yolk fully comparable with butter fat as a source of Vitamin A. in 1909, McCollum fed two young white rats on egg yolk alone for 18 weeks. Both rats gained adequate weight and one gave birth to eight young. In contrast, the results of feeding egg white alone showed its inadequacy for supplying nutritive requirements, for the rat quickly lost weight, developed a disease indicative of deficiency in Vitamin A, and death occurred. Goldberger, from results of his work on pellagra, recommends meat, salmon, and egg yolk as being rich in the pellagra—preventive factor otherwise known as Vitamin G, a component of Vitamin B.

The mineral elements of the egg are sufficient for the development of the chick, hence, it is logical to assume, for the human body. The iron in egg is in an especially valuable form because it is readily utilized. In a comparison of egg yolk and bran as sources of iron in the human dietary at Columbia University, the data derived indicates that the iron of egg yolk and of bran prepared for human consumption by steaming and toasting can be used with equal efficiency for the maintenance of iron equilibrium in the human adult. Calcium and phosphorus are found chiefly in the yolk. Eggs also contain sulfur in appreciable amounts.

The digestibility of the egg is excellent. The proteins are easily and almost completely utilized; the fats are in a finely emulsified form and thereby easily assimilated. The extent of cooking may influence the ease of digestion. Hard-cooked and soft-cooked eggs call forth the same degree of gastric response, but the first are a little slower in leaving the stomach; scrambled eggs are still slower. The coefficient of digestibility of raw egg whites varies from 50 to 80, and is lower than properly cooked egg whites. Absorption varies with the method of preparation, being less for raw egg whites in natural state than when beaten light. There is no difference nutritionally between brown shelled and white shelled eggs.

A popular misconception of today is that the habit of eating soft foods has greatly increased incidence of dental diseases. However, the information on such diseases as dental caries has been slowly accumulated for nearly 2000 years. That dental caries may be arrested if the patient will eat the proper food seems probable from the investigation of Davis, Boyd, Drain, Nelson, Bunting, Hadley, Jay and Hard. A diet rich in Vitamins A and D will improve general health and incidentally body tissues. The dietary essentials for children are as follows:

A quart of milk a day, one egg, teaspoon of cod-liver oil, ounce of butter, one orange, two or more succulent vegetables, and fruits, and such other foods as the child desires. Caloric requirements may be supplied either by fats or carbohydrates. The results were the same, and dental caries were arrested in all cases using this dietary prescription. Since many dentists, dietitians, and biochemists maintain that dental caries is a result of over-ingestion of carbohydrates, the investigators point definitely to the fact that the exclusion of essential foods by an excessive intake of carbohydrate with its deleterious results may be due to the lack of vitamins and minerals rather than to over-ingestion of carbohydrate.