Elmer V. McCollum

"Subsistence throughout life on a strictly carnivorous diet will prevent dental caries. This would be impractical in most parts of the world, and if practicable, would be less satisfying than is a mixed diet. The presence of considerable carbohydrate in the diet is necessary for the development of carious teeth. There seems to be good evidence in support of the view that the regular consumption of a diet in which all the essential nutrients are present in adequate amounts, and in which the ratio of fatty acids to total carbohydrates (including the sugar which may arise from protein and glycerol) is not less than 1.5:1, prevents dental caries. This is equivalent to saying that a diet suitable for the diabetic is so constituted as to afford protection against dental caries, and even makes possible the arrest of the carious process in open cavities. This protective action of excessive fat in the diet may possibly be due to greasing the tooth surface and the cavity surface, thus waterproofing it and preventing access of water-soluble acids (for example, lactic acid) to the enamel surface."