FDA ADVISORY COMMITEE REVIEW OF NUTRITIONAL HEALTH CLAIMS
This article was originally published in The Tan Sheet
FDA ADVISORY COMMITEE REVIEW OF NUTRITIONAL HEALTH CLAIMS would be one way for FDA to arrive at "significant scientific agreement" that a claim should be authorized, John Milner, PhD, Pennsylvania State University, suggested at a Nov. 1-3 FDA public conference on antioxidant nutrients and cancer/cardiovascular disease in Washington, D.C. Speaking during a scientific panel on "significant scientific agreement" for nutritional health claims on Nov. 3, Milner recommended that FDA establish a "standing advisory committee" to review health claims as well as hold "some kind of a consensus hearing" to review claims. Under the Nutrition Labeling & Education Act, FDA is required to determine that there is "significant scientific agreement" that a health claim is valid before authorizing it. The issue of how FDA interprets "significant scientific agreement" has been hotly debated. The dietary supplement industry has argued that the agency is taking an overly strict interpretation of the term. At a recent hearing of the Senate Labor & Human Resources Committee, Sen. Tom Harkin (D-Iowa) suggested that Congress provide FDA with guidance on how to interpret "significant scientific agreement" ("The Tan Sheet" Oct. 25, p. 1). The Nov. 1-3 symposium included separate scientific panels that were asked to review health claims for vitamin A, vitamin E and beta carotene. FDA Office of Special Nutritionals Acting Director Elizabeth Yetley, PhD, said the agency was looking for "a lively discussion on the state of the art of the science related to the topic of antioxidant vitamins and [the] risk of cancer and heart disease both in very broad terms as well as in several very specific cases." Yetley called on the invited scientists and participants to focus on "the strength of the scientific evidence that support a particular nutrient/disease relationship" and to avoid getting caught up in the terminology of health claims. She also asked the scientists to consider "what the science says" to them -- its strengths, weaknesses and conclusions. FDA will then "take this and compare it" against the legal standards, Yetley said. The agency, the FDAer concluded, "needs constructive and creative guidance" on how to interpret the available data. In an Oct. 14 notice, the agency explicitly disallowed health claims for antioxidant vitamins and cancer/cardiovascular disease for dietary supplements, citing a lack of available data supporting the nutrient-disease relationships ("The Tan Sheet" Oct. 11, p. 1). FDA turned down similar health claims for conventional foods in January. FDA Deputy Commissioner for Policy Michael Taylor noted at the conference that "FDA is depending on this scientific meeting as a very important part of its decision making with regard to antioxidant vitamins and cancer and antioxidant vitamins and heart disease. We're going to rely on the discussions here as a critical part of our administrative record." Taylor also called the meeting "precedent setting" because it is an "indication . . . of how FDA is committed to reaching out to the scientific community as it evaluates these health claims." The panel focusing on the issue of how to interpret significant scientific agreement for health claims was, in general, reluctant to provide FDA with a specific regulatory yardstick. Panel member C. J. Schorah, a pathologist at the University of Leeds (U.K.), observed that determining "significant scientific agreement" is "where it gets tricky." "If we're talking about taking something like a [vitamin] all the way to whether it prevents cancer, a major disease affecting millions of people worldwide," Schorah said, then the "levels of opinions that are obtained must be wide," and must include the opinions of "scientists in all sorts of different fields." Milner concurred, suggesting that the panel must "look at the overall picture." Julie Buring, ScD, Brigham and Women's Hospital, added that the level of agreement needed "is very much dependent on the particular research question that we're asking." Schorah also expressed an opinion echoed by many other panel members that data supporting the link between antioxidants and cancer/cardiovascular disease -- particularly for dietary supplements are not adequate to approve a health claim. Although the studies "presented [are] of high quality," Schorah stated, "the depth of the information is particularly shallow" because "we don't have . . . many completed intervention studies with antioxidants." Moreover, he added, "we may find that two or three intervention studies published in the next two or three years [may] completely overturn" the current evidence. Buring, who emphasized that she would be in favor of "putting health claims anywhere that they're appropriate," agreed with Schorah: "If, for example, we believe that in this particular situation clinical trials would make a difference and know that they are upcoming," she stated, "then what we don't want to do is be in the position where we say something today and we change it six months down the road." Milner also agreed that a definitive health claim for antioxidants could not be formulated based on currently available data. "I would endorse some kind of statement saying that antioxidants may reduce your risk of some types of cancers," he conceded, but "I don't know that we can be stronger or more opinionated than that." Prior to the panel's deliberations, Taylor outlined issues that FDA has been grappling with in attempting to interpret the term "significant scientific agreement." On the most basic level, Taylor asked: "What is the quantity and quality of evidence that we need? Do you need more than one study? Do you need an array of types of evidence?" Then, once "you have a particular body of evidence on the table," Taylor continued, "what constitutes significant agreement among scientists? Do some scientists' opinions matter more than others?" Moreover, if "you're talking about a cancer claim, for example, do we weigh the opinions of scientists with a certain [cancer] expertise more than others?" Taylor asked. The FDAer also asked the panel what should be done if "FDA scientists believe that a claim is valid but there's still significant reservations in the outside scientific community." In addition, Taylor questioned how, in attaining significant scientific agreement, FDA can "tease out the difference between the views scientists may have about the utility of health claims" in general "from their assessment of the data." The members of FDA's Food Advisory Committee and Folic Acid Subcommittee, for example, were divided on the issue of whether health claims should be allowed on food and supplement labels in general, irrespective of whether a health claim for folic acid should be authorized ("The Tan Sheet" Oct. 18, p. 14). Taylor also asked the panel members about which "process to follow" in determining scientific agreement, such as whether the agency should convene a "standing advisory committee of outside scientists to help advise FDA," or whether FDA should hold a "regular series of conferences or fora like this."
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