Photo: The Canadian Press. All rights reserved.

Tony Johnson with Canada Dry delivers 7Up and Canada Dry products in Alexandria, Va. on Wednesday, Oct. 10, 2007. Cadbury Schweppes announced plans to spin off its US beverage division that includes the 7Up, Snapple, and Dr. Pepper brands to its shareholders rather than sell it. (AP Photo/Jacquelyn Martin)

An advocacy group wants to take the fizz out of 7-Up's antioxidant claims.

The Center for Science in the Public Interest, which advocates for food safety and nutrition, is part of a lawsuit against Dr Pepper Snapple Group Inc. for touting an added antioxidant in some 7-Up varieties.

The lawsuit, which was filed Thursday in U.S. District Court in California, says the claim is misleading because it gives the impression the antioxidants come from fruit rather than added Vitamin E. The group also notes that the Food and Drug Administration prohibits companies form fortifying candies and soft drinks with nutrients.

The suit was filed on behalf of a California man who bought the drinks but says he didn't know the antioxidants didn't come from juices.

7-Up Cherry Antioxidant, Mixed Berry Antioxidant, and Pomegranate Antioxidant were launched in 2009. Despite the pictures of cherries, blackberries, cranberries, raspberries and pomegranates on various 7UP labels, the drinks contain no fruit or juice of any kind.

Representatives from Dr Pepper and the FDA did not immediately respond to requests for comment.