these components and the risk of these diseases. The FDA logically determined that the specific effect of the component of the food constituting the dietary supplement could not be determined with certainty… . But certainly this concern could be accommodated, in the first claim for example, by adding a prominent disclaimer to the label along the following lines: “The evidence is inconclusive because existing studies have been performed with foods containing antioxidant vitamins, and the effect of those foods on reducing the risk of cancer may result from other components in those foods.” A similar disclaimer would be equally effective for the latter two claims.
The FDA’s concern regarding the fourth claim—“0.8 mg of folic acid in a dietary supplement is more effective in reducing the risk of neural tube defects than a lower amount in foods in common form”—is different from its reservations regarding the first three claims; the agency simply concluded that “the scientific literature does not support the superiority of any one source [of folic acid] over others.” But it appears that credible evidence did support this claim (concluding that “losses [of folic acid] in cooking and canning [foods] can be very high due to heat destruction”), and we suspect that a clarifying disclaimer could be added to the effect that “The evidence in support of this claim is inconclusive.”
The government’s general concern that, given the extensiveness of government regulation of the sale of drugs, consumers might assume that a claim on a supplement’s label is approved by the government, suggests an obvious answer: The agency could require the label to state that “The FDA does not approve this claim.” Similarly, the government’s interest in preventing the use of labels that are true but do not mention adverse effects would seem to be satisfied—at least ordinarily—by inclusion of a prominent disclaimer setting forth those adverse effects.
The government disputes that consumers would be able to comprehend appellants’ proposed health claims in conjunction with the disclaimers we have suggested—this mix of information would, in the government’s view, create confusion among consumers. But all the government offers in support is the FDA’s pronouncement that “consumers would be considerably confused by a multitude of claims with differing degrees of reliability.” Although the government may have more leeway in choosing suppression over disclosure as a response to the problem of consumer confusion where the product affects health, it must still meet its burden of justifying a restriction on speech—here the FDA’s conclusory assertion falls far short.
We do not presume to draft precise disclaimers for each of appellants’ four claims; we leave that task to the agency in the first instance. Nor do we rule out the possibility that where evidence in support of a claim is outweighed by evidence against the claim, the FDA could deem it incurable by a disclaimer and ban it outright.39 For example, if the weight of the evidence were against the hypothetical claim that “Consumption of Vitamin E reduces the risk of Alzheimer’s disease,” the agency might reasonably determine that adding a disclaimer such as “The FDA has determined that no evidence supports this claim” would not suffice to mitigate the claim’s misleadingness. Finally, while we are skeptical that the government could demonstrate with empirical evidence that disclaimers similar to the ones we suggested above would bewilder consumers and fail to correct for deceptiveness, we do not rule out that possibility.
B. The Unarticulated Standard
Wholly apart from the question whether the FDA is obliged to consider appropriate disclaimers is appellants’ claim that the agency is obliged to give some content to the phrase “significant scientific agreement.” …
Consideration of this constitutional claim seems unnecessary because we agree with appellants that the APA requires the agency to explain why it rejects their proposed health claims—to do so adequately necessarily implies giving some definitional content to the phrase “significant scientific agreement.” We think this proposition is squarely rooted in the prohibition under the APA that an agency not engage in arbitrary and capricious action. It simply will not do for a government agency to declare—without explanation—that a proposed course of private action is not approved. (“The agency must … articulate a satisfactory explanation for its action… .”). To refuse to define the criteria it is applying is equivalent to simply saying no without explanation. Indeed, appellants’ suspicions as to the agency’s real reason for its volte‐face on the general folate‐neural tube defect claim highlight the importance of providing a governing rationale for approving or rejecting proposed health claims.
To be sure, Justice Stewart once said, in declining to define obscenity, “I know it when I see it,” which is basically the approach the FDA takes to the term “significant scientific agreement.” But the Supreme Court is not subject to the Administrative Procedure Act. Nor for that matter is the Congress….
That is not to say that the agency was necessarily required to define the term in its initial general regulation—or indeed that it is obliged to issue a comprehensive definition all at once. The agency is entitled to proceed case by case or, more accurately, subregulation by subregulation, but it must be possible for the regulated class to perceive the principles which are guiding agency action. Accordingly, on remand, the FDA must explain what it means by significant scientific agreement or, at minimum, what it does not mean.
….
For the foregoing reasons, we hold invalid the four subregulations, 21 C.F.R. § 101.71(a), (c), (e); § 101.79(c)(2)(i)(G), and the FDA’s interpretation of its general regulation, id. § 101.14. The decision of the district court is reversed, and the case is remanded to the district court with instructions to remand in turn to the FDA for reconsideration of appellants’ health claims.
So ordered.
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NOTES AND QUESTIONS
1 5.2. Association versus causation. Many epidemiological studies of dietary intake of conventional foods have led to a promising hypothesis concerning a benefit for a particular nutrient only to subsequently be demonstrated via an intervention study that the nutrient‐containing dietary supplement did not confer a benefit or actually was harmful. For example, a number of studies revealed that diets high in fruits and vegetables containing dietary beta carotene were associated with a lower risk of developing lung cancer, particularly among smokers. Beta carotene is known to be an antioxidant and thus provided a plausible mechanism. However, beta carotene intervention trials absolutely dispelled that hypothesis and even showed there was an increase in lung cancer among smokers after they consumed beta carotene dietary supplements. See Alice H. Lichtenstein & Robert M. Russell, Essential Nutrients: Food or Supplements?: Where Should the Emphasis Be? 294 JAMA 351–358 (2005).
2 5.3. Qualifying weak evidence. The claim requested by Pearson, “Consumption of antioxidant vitamins may reduce the risk of certain kinds of cancer,” at that time was considered factually accurate but misleading because of the limits in the evidence. The Pearson v. Shalala court indicated that FDA had “logically determined” that the consumption of antioxidant dietary supplements could not be scientifically proven to reduce the risk of cancer. The court, however, concluded that antioxidant vitamins could nevertheless make a cancer prevention health claim if accompanied by a qualification such as, “The evidence is inconclusive because existing studies have been performed with foods containing antioxidant vitamins, and the effect of those foods on reducing the risk of cancer may result from other components in those foods.” Do you agree with the court that the qualifying statement cured the misleading nature of the cancer prevention claim? Do you think the court understood the nature of the scientific evidence?
3 5.4. Hypothesis versus reliable scientific evidence. Of the four claims submitted in Pearson v. Shalala, three involved evidence supporting a hypothesis—in some cases promising support, but nonetheless, no direct evidence to support the claims. Moreover, even if beneficial effect of a component in the food had been determined, there was no evidence that the component would have the same effect if taken as a dietary supplement. In short, there was no reliable evidence to support the claims. Are consumers able to understand