Pepsi Acid Powerful, But Not As Strong As Stomach's

It can kill many viruses and bacteria on contact, can dissolve human teeth and even corrode building nails.

But it's not marketed as a solvent or sold at the hardware store in child-proof containers. It's available almost everywhere in easy-to-open, 12-ounce cans.

And when you get it home, you don't tuck it high on a shelf where the kids can't get it. You simply pop open a can, pour it over ice and drink it.

When reports of potential Pepsi tamperings surfaced - most of which are now viewed skeptically - one of the first things Pepsi bottlers and health officials wanted people to know was this: There's little chance a virus or bacteria could be passed along in soda pop.

Hardly anything, the public was told, can survive in the stuff.

Although the news was meant to be reassuring, it caused some to wonder just how prudent it is to gulp down a fluid so potent that many life forms would be snuffed out if they were dipped in it.

Some remembered high-school biology classes in which a human tooth left in a glass of cola was said to dissolve in a few days.

But heath officials say that as strong as Pepsi is, the human stomach is much stronger.

"Stomach acid is basically hydrochloric acid, an incredibly hearty acid that's there for a purpose, to protect us from bacteria and other invaders," said Bert Bartleson, technical expert with the state Health Department's food program.

The phosphoric acid in cola-type soft drinks carries a Ph factor of 2 while the hydrochloric acid in stomach fluids has a Ph factor of about 1, meaning it is 10 times as strong as the acid in pop.

Consequently, the stomach lining that protects people from their own digestive juices is more than adequate to withstand the acids in Pepsi, health officials say.

"Common sense tells us that people have been drinking it for years and we don't see any gross problems around it," said Susan Adams, a dietician with the University of Washington's clinical-research unit.

Although most viruses would quickly succumb to the acids in Pepsi, that may not be true for the hepatitis B, a particularly strong and long-lived virus, said George Kenny, a UW professor of pathobiology.

But no contamination has been found in the reported Pepsi-tampering incidents, and most cases across the country are now being dismissed as copycats and hoaxes.

Not everyone enjoys soda pop and not everyone can tolerate it; certain people may be sensitive to the sugar, or the artificial sweetener, or the caffeine in some drinks.

But soft drinks in moderation are unlikely to pose a problem for most people, Adams said.

The ingredient in soda pop most likely to cause problems for people is not the acid but the sugar, dentists say.

"Certainly, pop and any kind of sweet that is bathing the teeth in sugar can promote dental decay," said Dr. Victor Barry, president-elect of the Washington State Dental Association.

Sugar combines with the bacteria in plaque on the teeth to form an acid that causes cavities, Barry said. That's why dentists suggest people switch to sugarless soft-drink varieties.

The news about Pepsi's potency caused some soda-drinkers to wonder for the first time just what's in their favorite beverage.

The ingredients are listed on the side of the can: carbonated water, corn syrup, sugar (or Nutrasweet, in the diet version) phosphoric acid, caffeine, citric acid and flavorings (which Pepsi says include cola nut and vanilla).

But the precise proportions and the way they are mixed is a closely guarded trade secret, known to only a few top employees.

"Just as you can bake a cake a million different ways, you can make a soft drink a million different ways," said Pepsi spokesman Andrew Giangola.

Giangola preferred not to comment on his product's ability to dissolve teeth and metal, other than to insist it's not dangerous to humans.

"People have been enjoying Pepsi since 1898 and hopefully will enjoy it for a long time after this," he said. "I think everything in moderation is the answer."