Cola Drinks

The following is an extract from a United States government bulletin. We would believe, therefore, that it is accurate.
"The popular cola drink is a strange mixture of phosphoric acid, sugar, caffeine, coloring and flavoring matter. The amount of phosphoric acid is 55%, giving cola drinks an acidity of pH 2.6, or about the same as vinegar. Why doesn"t cola drink taste like vinegar? Because of the sugar added."
"But why so much phosphoric acid? Evidently to keep the water sterile, as no bacteria can live in such acid solutions. The solution of phosphoric acid in cola drinks is so strong as to cause human teeth to become soft within 2 days. In fact, it is strong enough to dissolve nails and limestone, and the very substantial amount of caffeine in the cola drinks, without doubt has a direct bearing on the prevalence of gastric ulcers."
Food Products, pp.87-96,
U.S. Government Printing Office,
Washington D.C., 1951
One can only wonder whether the friendly bacteria in our intestines are able to survive in such strong acid solutions?
Here is another report that confirms the above.
"In 1951, a doctor who had been in charge of nutritional research for the U.S. Navy during World War II testified before a congressional committee. (When the Navy discovered the amount of money their men were spending on Coca-Cola, all cola beverages were studied. It was found they contained about 10 percent sugar.) The soft drink industry was given sugar rationing certificates so they could collect on all sugar sold to the armed forces. The Navy nutritionist, Dr. McCay, began studying these certificates: "I was amazed to learn," he testified, "that the beverage contained substantial amounts of phosphoric acid.... At the Naval Medical Research Institute, we put human teeth in a cola beverage and found they softened and started to dissolve within a short period." While the congressmen gaped, the doctor went on: "The acidity of cola beverages... is about the same as vinegar. The sugar content masks the acidity, and children little realize they are drinking this strange mixture of phosphoric acid, sugar, caffeine, colouring, and flavouring matter."
"A congressman asked the doctor what government bureau had charge of passing on the contents of soft drinks."
"So far as I know, no one passes upon it or pays any attention to it," the doctor replied.
"No one passes on the contents of soft drinks?" asked the congressman.
"So far as I know, no one."
"Another congressman asked if the doctor had made any tests of the effect of cola beverages on metal and iron. When the doctor said he hadn’t, the congressman volunteered: "A friend of mine told me once that he dropped three tenpenny nails into one of the cola bottles, and in forty-eight hours the nails had completely dissolved."
"Sure," the doctor answered. "Phosphoric acid there would dissolve iron or limestone. You might drop it on the steps, and it would erode the steps coming up here....Try it."
(William Dufty, Sugar Blues, p.177-8)

Cola drinks and many other soft drinks contain caffeine. Click here for more information on the psychological effects of caffeine. Click here to read about the harmful effects of other products that contain caffeine - such as tea, coffee, and chocolate.