Is caffeine added to soda pop to enhance flavor, or to hook consumers?

Researchers at Johns Hopkins University conducted a small test of 25 adults. Only eight percent could tell the difference between drinks that have caffeine and drinks that don't.

Researchers say caffeine is a mildly addictive, mood-altering drug. The study's authors suggest that caffeine is added to colas not for flavor, but to hook consumers.

The study likened the marketing of caffeinated colas to the tobacco industry's early claims that the addictive stimulant nicotine was added to cigarettes for flavor.

A spokesman for the National Soft Drink Association blasted the report as hogwash, saying caffeine is added for flavor only.

In 1981 the FDA proposed caffeine be eliminated from colas. Soda makers responded by saying the caffeine enhanced flavor.

The results of the Johns-Hopkins studay appear in August's "Archives of Family Medicine," published by the American Medical Association.

In 1998 Americans guzzled 15 billion gallons of soda. That's about 585 cans for every man, woman and child. Today more soda is consumed than water.