Eggs at best are poor foods while modern methods of egg production, involving great overstimulation of laying strains, produces eggs of a very poor quality. Egg eating usually involves over consumption of protein.
Raw egg white, so often urged as food for invalids, is poorly digested and assimilated. From thirty to fifty per cent of the amount consumed passes through the digestive canal without being digested and absorbed. Raw egg white may produce diarrhea and sometimes vomiting.
Egg whites are acid forming, and produce in some stomachs almost deadly acids. It is asserted that "practically all constipated people are sensitive to white-of-egg poisoning."
Invalids, inactive people and those inclined to constipation should especially avoid egg whites. They are bad food for children. Eggs should certainly never be eaten by one whose liver or kidneys are not in perfect condition.
Because Beaumont, in his experiment upon Alexis St. Martin, noticed that raw egg whites left the stomach very quickly, in less time in fact than the other foodstuffs he investigated, the idea grew that raw egg white is the most easily digested of all food substances.
Pavlov showed that egg white, unlike other proteins, does not stimulate the flow of gastric juice. Abderhalden discovered that pepsin does not act readily upon egg white. Okada showed that pancreatic juice and bile are both indifferent to egg white. Very little bile is poured out and trypsin has no effect whatever upon raw egg white. Other investigators have confirmed these findings.
Vernon, Hetin and others have shown that raw egg white hinders the digestion of other substances. Bayliss, Prof. of Physiology, University of London, (The Physiology of Food and Economy in Diet), says that raw egg white contains some substance which even in small amounts, hinders the action of the digestive fluids. Lemoine, a French authority, after careful study, says raw egg white contains a poison which damages the kidneys.
The yolk of the egg seems to be less objectionable and is an alkaline-ash food, whereas the white is an acid-ash food. Egg yolks are easily digested and, if taken raw are not the source of any trouble. I can, however, see no reason for using egg yolks, a practice that is rather expensive.