Study disputes soft drink manufacturers on caffeine

From staff and wire reports

CHICAGO -- Most people cannot taste the difference between caffeinated and non-caffeinated sodas, according to a new study, even though soft drink manufacturers say they add caffeine to enhance flavor.

The researchers said the high consumption of caffeinated soft drinks more likely reflects caffeine's addictive properties, not its flavor-enhancing qualities. Roughly 70 percent of soft drinks consumed in the United States contain caffeine, the study said.

The study was conducted at Johns Hopkins University School of Medicine and appeared in Archives of Family Medicine, which is published by the American Medical Association.

The Johns Hopkins study found that only 8 percent of a group of 25 adult consumers were able to detect the caffeine in sodas. The rest could not tell the difference between caffeinated and non-caffeinated drinks until caffeine levels were raised to levels beyond those approved by the Food and Drug Administration.

The volunteers were people who regularly drank caffeinated colas.

To conduct their experiment, the researchers added different amounts of caffeine to a commercial brand of caffeine-free cola. The volunteers compared the taste of the doctored cola to a sample of the original uncaffeinated beverage.

A trade group representing the soft drink industry called the study "fatally flawed" and contended caffeine added to the beverages does enhance flavor.

"It was a very poorly conducted and designed study. The conclusions are irresponsible and they were not based on the science," said spokesman Jeff Nedelman of the National Soft Drink Association.

The group said several of the taste testers in the study should have been excluded because they are smokers, with depressed senses of taste. It also said the tasters likely experience "flavor fatigue" from tasting too many warm sodas over a brief period.

Soft drinks contain only a fraction of the caffeine present in coffee, Nedelman added.

The report's author, Roland Griffiths, noted that caffeine-free versions of Coca-Cola Classic and Pepsi, the two most popular soft drinks, made up only 5 percent of sales.

Soft drinks represent the single largest source of added sugar in the U.S. diet, according to sources cited in the study. Soda drinking displaced consumption of more nutritional foods and could lead to more tooth decay, obesity and bone fractures, the report said.

In 1998, Americans guzzled 15 billion gallons (57 billion liters) of soda, an average of about 585 cans per person. Consumption of soft drinks has more than doubled since 1975, and more soda is consumed than water.

"We know adults and children can become physiologically and psychologically dependent on caffeinated soft drinks, experiencing a withdrawal syndrome if they stop," Griffiths said in the study.

"Most adults can become informed about, and cope with, withdrawal. ... But it is more problematic in children who are less well informed and whose soft drink consumption may be sporadic," he said.

Griffiths said manufacturers should explain their reasons for adding caffeine to drinks and spell out the amount of the additive used.

Soda makers responded to a 1981 FDA proposal that caffeine be eliminated from cola drinks by saying it enhanced flavor.

Reuters contributed to this report.

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Archives of Family Medicine
National Soft Drink Association
Journal of the American Dietetic Association -- Soft drink consumption among U.S. children and adolescents

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