The CRA, a national trade association representing the corn refining (wet milling) industry of the United States, launched an advertising and public relations campaign to address the "many myths, inaccuracies and untruths associated with the sweetener" , which have been linked to obesity.
Now the Center for Science in the Public Interest wants the association to change some of the text used in the campaign which claims that high-fructose corn syrup (HFCS) "has the same natural sweeteners as table sugar".
CSPI's executive director Michael F Jacobson says the text is deceptive because HFCS consists almost entirely of glucose and fructose and not a single molecule of sucrose.
It comes just a few months after the two organizations outlined their joint position on the subject in February.
Jacobson told FoodNavigator-usa.com: "The Corn Refiners could simply and quickly change the text to make their ads honest and non-deceptive.
"Sugar is 100 percent sucrose.
It is true that adding a water molecule to sucrose and splitting it in half yields one molecule each of glucose and fructose, but that is not the same as saying that HFCS and sugar contain the same sweeteners.
"It is also deceptive to imply that HFCS is natural.
HFCS starts out as cornstarch, which is chemically or enzymatically degraded to glucose (and some short polymers of glucose).
Another enzyme is then used to convert varying fractions of glucose into fructose.
"High fructose corn syrup just doesn't exist in nature."
Jacobson added that the "harmfulness" of HFCS had become an urban myth as nutritionally, HFCS and sucrose may be identical.
But he said: "That's no excuse for this deceptive advertising campaign."
Audrae Erickson, president of the CRA, would not say if they planned to change the text in question, referring instead to a document and jointly signed letter by the CRA and the CSPI.
This demonstrated what she described as "our common position" that "HFCS, like table sugar and honey, is composed of fructose and glucose, which are found in many other naturally-occurring foods".
Erickson claims that essentially HFCS is the same as table sugar and honey, and has the same number of calories.
She also says it is natural as it is made from corn, a natural grain product and contains no artificial or synthetic ingredients or color additives.
The CRA's newspaper, magazine and television advertisements aim to provide "balanced information about high fructose corn syrup to allow consumers to make informed decisions based on science".
Obesity HFCS is commonly used in soft drinks and processed foods and has been associated with rising obesity levels.
Obesity is currently thought to affect more than 64 per cent of the US's adult population, and 16 per cent of children, and has been repeatedly linked with an increased risk of other health conditions such as heart disease and diabetes.
This month the American Medical Association (AMA) concluded after studying current research, that it does not appear to contribute more to obesity than other caloric sweeteners.
It said there was currently insufficient evidence to restrict the use of high fructose syrup or label products that contain it with a warning.
But it called for further independent research to be done on the health effects of high fructose syrup and other sweeteners.
A recent survey by the MSR Group on behalf of the CRA revealed that more than two-thirds of respondents did not know that high fructose corn syrup and table sugar have the same number of calories Almost two-thirds of those surveyed do not understand that high fructose corn syrup contains the same simple sugars - glucose and fructose - as table sugar Legal challenges This month a US federal judge rejected a claim by Stacy Holk, who filed the suit on behalf of herself and other consumers, that the use of the term 'all natural' on Snapple drinks was deceptive because the products contained HFCS.
The case, which was decided on preemption grounds, was filed by judge Mary Cooper from the US District Court of New Jersey.
The discrepancy arises from the lack of a clear definition of the term 'natural' from the nation's Food and Drug Administration (FDA).
However, Judge Cooper said it was up to FDA, not the court, to define 'natural'.
And last year, both Cadbury Schweppes and Kraft faced lawsuits after making 'natural' label claims on 7Up and Capri Sun respectively.
Both companies changed the labeling of their products before any legal action was taken.
FDA does not define the term 'natural', and it has therefore been left open to different interpretations.
However, the FDA has said that products containing HFCS cannot be considered 'natural' and should not be labeled as such.
In response to an inquiry from FoodNavigator-USA.com, the regulatory agency examined the composition of HFCS, which it said is produced using synthetic fixing agents.
"Consequently, we would object to the use of the term 'natural' on a product containing HFCS" , according to the agency's Geraldine June.