This section is from the book "Dietetics", by Alexander Bryce. Also available from Amazon: Modern Theories of Diet and Their Bearing Upon Practical Dietetics.
There is not the slightest doubt that originally this term was used to signify bread which was made from stone-ground flour manufactured from the whole grain of wheat, the colour of which without compromise was distinctly and decidedly brown. It has been stated over and over again that the regular use of this bread would have prevented the decay of the teeth which is such a prominent feature amongst all classes to-day, and I am inclined to support this belief.
But it is also true that the introduction of this bread was responsible in some measure for the very evil which it would have stayed had it been permitted, and this paradox is easily explicable.
It was soon found that wholemeal bread required a considerable amount of mastication - the sole reason for the existence of good teeth, because whenever an organ is well used it becomes healthy, and when it ceases to be used, Nature quickly removes it or causes it to atrophy. It is not, therefore, a question of an extra amount of mineral salts or indeed any other ingredient of the wholemeal which is of such outstanding value to the teeth. It is simply and solely because the introduction of bread made from it compelled a more thorough use of the teeth, and the pace which was set in the last half of the nineteenth century being far too fast to permit of the mastication of wholemeal bread, it was soon discarded as nasty and unfit to eat.
Prodigious efforts were made by bakers to perpetuate its use under the designation of brown bread, and substitutes containing a little malt, or simply white flour with an admixture of bran, obtained a certain vogue, and still persist to-day. These possessed the great advantages, from the public point of view, that they required much less mastication and were not nearly so liable to become dry and hard as wholemeal bread. They therefore rapidly became popular amongst those who considered it judicious to shun the use of white bread, under the mistaken conception that they were of equal dietetic value with bread made from stone-ground flour manufactured from the whole grain of wheat.
 
Continue to: