Studies of Urinary Acidity. I. Some Effects of Drinking Large Amounts of Orange Juice and Sour Milk

It is known that the eating of most fruits leads to the formation of less acid urines due to the excess of base-forming elements in the fruits. The organic acids contained in the various fruits are oxidized within the body to carbon dioxide and water, so that the net result to the organism is a gain in base. However fruits such as cranberries, prunes, and plums, which contain benzoic acid or its precursors, cause the production of more acid urines. This result is, doubtless, in part due to the synthesis of hippuric acid (Blatherwick, 1914). During the progress of a study of the neutrality regulation of cattle, it was observed that a cow fed large amounts of corn silage, a product with an excess of base-forming elements, excreted an acid urine and showed a reduction in the plasma carbon dioxidecombining power (Blatherwick, 1920). The belief was then expressed that these effects were probably caused by the incomplete oxidation of the contained organic acids. The organic acids of corn silage are chiefly racemic lactic, acetic, and butyric, (Dox and Neidig, 1912, 1913). In view of the foregoing, the question arose as to whether the tolerance of man for naturally occurring fruit acids could also be passed. Orange juice was chosen for study because of its wide-spread use, and owing to the observation of Newburgh and Marsh (1920) that one of their diabetic patients succumbed after eating a bag of oranges.