The class action, filed in a Missouri court in 2004 and certified in 2006, sought as co-defendants all Missouri residents who had consumed Diet Coke after March 24, 1999, which meant Coca-Cola was facing a potential multi-million dollar payout if the challenge succeeded.
Coke wins it But the Missouri Supreme Court this week ruled the grounds on which the district court certified the class action were "overly broad", so broad in fact that no financial estimate for the action was tabulated.
The action "undoubtedly includes an extremely large number of uninjured class members, that is, those who did not care if the Diet Coke they purchased contained saccharin," Judge William Ray Price Jr wrote in the Supreme Court's verdict.
"Consumers would have to not only recall the amount of fountain Diet Coke they purchased out of the innumerable fountain beverages they purchased during the past five years, but also that they would have not purchased fountain Diet Coke if they had known it contained saccharin."
No win for saccharine The action, brought by a Missouri resident named Diana Pennington, alleged Coca-Cola misled consumers because the fountain version of Diet Coke contained aspartame and saccharin whereas Diet Coke in bottle and can form contained only aspartame.
Coca-Cola said it used saccharin in fountain versions of Diet Coke because it better retained sweetness when stored for long periods of time.
It noted this had been the case since 1984.
In its defense Coca-Cola said it was not required to disclose ingredients in fountain Diet Coke at the point-of-sale because it is not sold in a pre-packaged format such as a bottle or a can but said some retailers posted ingredients lists in public areas or in brochures.
Pennington said she would not have purchased fountain-form Diet Coke had she known it contained saccharin as she believed the sweetener had been linked to cancer in trials on rats.
The Food and Drug Administration (FDA) has since stated these studies have little relevance to human consumption of saccharin and gave it an official clean slate in 2000.
Indeed, saccharine, which is about 300 times as sweet as sucrose, is one of the oldest sugar alternatives on the US market and was first marketed commercially in the early part of the 20th century.
Judge Price said the class action would not have succeeded even if alleged injuries could have been more readily defined as they remained too indefinite.
Price wrote: "The definition cannot be based on an individual's subjective preference.
Such a modification would result in innumerable 'mini-trials' to determine class membership."
Pennington's action follows similar actions filed in several other US states including California, Florida, Illinois, Kansas and Massachusetts all of which had been rejected.
"It has been our view all along that this case and other similar cases have no merit," said Coca-Cola spokesperson Ray Crockett .
"Saccharin has been found to be safe, just as have the other sweeteners we use in our products."