The Food and Drug Administration recently approved health claims on food that are qualified by statements weighing up the level of evidence supporting it.
If the claims are not supported by 'significant scientific agreement', they will carry one of three disclaimers explaining that the evidence is 'promising but not conclusive', 'limited and inconclusive' or 'very limited and preliminary'.
But when consumers were asked to rate different claims by researchers from the FTC, most had difficulty distinguishing between different levels of evidence. In some cases they believed that qualified claims had more scientific evidence than unqualified claims, said Dennis Murphy, senior economist at the body that monitors advertising.
FTC has submitted its findings to the FDA, in response to a call for comments on health claims at a meeting held by the agency in October.
"It struck us when we attended the meeting that much of the research being presented reached the same conclusions that we had observed several years ago in our own research. We thought it would be helpful if we laid out the common findings," Murphy told NutraIngredients-USA.com.
He said that part of the problem with health claims is that unqualified claims - such as one that cites the role of calcium in protecting against osteoporosis - are not registering as a strong claim among consumers.
"We're starting off too low. We need to try to beef up unqualified health claims," he said.
FTC research recommends that stronger wording is used for unqualified health claims so that they may, for example, say 'very strong evidence' supports a specific health benefit.
All health claims should also reveal more about the evidence relating to the claim, said Murphy.
FTC is not the only group to criticize the language approved by FDA to convey health claims. Industry association NNFA has also submitted comments on the qualified health claims approved for use on foods in recent months, saying that the language "does not reflect the specific state of the science, but rather is standardized to fit a few defined scenarios based on the level of science submitted".
While industry believes the FDA needs to do more research in this area, Murphy said the FTC comments were aimed equally at academic researchers or food companies.
"Companies say that our language is not commercial enough. We don't have much expertise in drafting promotional claims so maybe a food industry group should carry out this kind of research," he said.
The results of previous tests by FTC show that it is possible to 'craft language that differentiates clearly among differing levels of scientific certainty', added the Commission in its comments.