Oct. 12, 2000 (Washington) -- Fiber may be good for you, but the label on fiber supplements will not be able to claim that consuming fiber may reduce the risk of colorectal cancer. That's one of two decisions the FDA made late Wednesday after grappling with the accuracy of this and three other nutrient-disease relationship claims for nearly four years.
The agency also ruled that folic acid supplements could not claim that 0.8 mg of the supplement is more effective in reducing the risk of neural tube defects than a lower amount available naturally in certain foods. Neural tube defects account for about 1,500 miscarriages or stillbirths each year in the U.S.
The FDA originally rejected the fiber and folic acid claims, as well as two other proposed dietary supplement claims, because the claims were misleading and not supported by scientific evidence. But in 1999, the U.S. Court of Appeals in Washington, D.C., ordered the agency to reevaluate its ruling, saying the decision against supplement makers infringed on their First Amendment rights to freedom of speech. Now the FDA backs its repeat decisions, saying it has a new, less stringent framework for evaluating proposed dietary supplement and disease relationship claims, which was applied to reevaluate the fiber and folic acid claims.
In the 1999 court case, Pearson v. Shalala, the dietary supplement makers challenged the FDA's decision rejecting claims for specific dietary supplement and disease relationships between dietary fiber and the prevention of colorectal cancer; antioxidant vitamins, such as vitamin C, and cancer; and omega-3 fatty acids and heart disease; and the claim that folic acid in supplement form is more effective in reducing neural tube defects than what is available in food.
The FDA rejected the folic acid claim, again calling it misleading; although the agency said some broad statements might be made about all folates, such as a broader term used to include natural foods. The FDA also determined that there was no convincing evidence to support a relationship between dietary fiber and the prevention of colorectal cancer. The FDA will decide on the other two claims regarding antioxidant vitamins and omega-3 fatty acids before the end of October.
The U.S. Court of Appeals also ruled in 1999 that the FDA's standards for reviewing health claims were ambiguous. Under the agency's regulations at the time, the FDA would authorize health claims for dietary supplements only if significant scientific evidence supported the claim. But in detailed letters, Christine Lewis, PhD, director of the FDA's office responsible for dietary supplement labeling, assured the supplement makers that this time the FDA also considered possible disclaimers -- and in using this new standard, fulfilled its obligation under the court order.
In the case of dietary fiber and colorectal cancer, Lewis wrote to the plaintiffs, "The evidence is no longer inconclusive. Results of four randomized, controlled intervention studies in humans consistently show a lack of relationship between dietary fiber and risk of colorectal cancer." In light of new evidence, she added that any disclaimer also would be misleading. "The weight of the evidence for a health claim about dietary fiber and colorectal cancer is outweighed by the evidence against such a claim," she wrote.
In the case of folates, Lewis told the plaintiffs that the proposed claim was misleading because it, too, was not supported by enough evidence and, as a result, improperly implied that the dietary supplement was more effective than food. The agency is "not aware of any statement that could adequately qualify this proposed claim," she added. But the FDA would entertain a qualified claim, promoting the possible effects of all folates on neural tube defects, she said.
Despite the outcome, the decision might satisfy both the court and the supplement industry.
Why? Because the new framework the FDA will use to review dietary supplement claims represents a significant shift away from the agency's previous standards, says William Soller, PhD, scientific director for Consumer Healthcare Products Association, a trade organization representing dietary supplement and over-the-counter drugmakers. Under the new system, the agency seems to be signaling that it will now take a broader look at the benefits of a claim rather than judging only the risk to consumers, Soller explains.
Soller adds that the FDA seems to be making an honest attempt to implement the Pearson decision. "They understand that a better risk assessment is needed," he tells WebMD.
The FDA says it will now evaluate all claims through this two-tiered system until it can finalize its proposed new rules. That means the agency will first determine if there is significant scientific evidence supporting a claim, but then, if there at least is some strong scientific evidence to support the claim, the FDA will entertain qualifying.
Still, reservations remain as to whether this new system will work and whether the agency can apply those standards consistently.
For one, the standard of significant scientific support sets the same high barrier established by the older standard, which automatically disqualified products due to a lack of substantial research, Soller observes.
"Only time can tell if this is a major shift. The proof is in the pudding," Soller tells WebMD.
The petitioners themselves could not be contacted for comment at the time this story was written.