As FDA examines health claims, CRN defends supplement effects
WASHINGTON —The Council for Responsible Nutrition last month submitted comments to the Food and Drug Administration regarding 3-of-4 qualified health claims and full-blown health claims (known as significant scientific agreements, or SSAs) that the agency said it is re-evaluating, including the use of soy protein in reducing the risk of coronary heart disease and the value of both antioxidant vitamins and selenium, separately, in reducing the risk of certain cancers.
CRN’s comments in a nutshell: the data continue to support the link between soy protein and a reduction in cardiovascular events; excluding some questionable meta-analyses published in recent years, the data supporting the supplementation of antioxidants to reduce the risk of certain cancers haven’t changed; and, similar to antioxidants, there is no large body of evidence that would suggest to the FDA that they should reconsider the qualified health claim in support of selenium supplementation.
Soy protein
SSA claim: “25 grams of soy protein a day, as part of a diet low in saturated fat and cholesterol, may reduce the risk of heart disease.”
“If the agency wants to change the [soy] claim in any way, they should consider what contributions might be coming from other soy components, like isoflavones and even soy fiber,” suggested Andrew Shao, CRN vice president of scientific and regulatory affairs. And because the data supports the benefits of soy isoflavones and soy fiber, “the present health claim shouldn’t be weakened,” Shao said. CRN, in its comment, identified 50 soy studies published since 1999, when the claim was first authorized, the vast majority of which supported the soy protein claim.
Antioxidants
Qualified health claim: “Some scientific evidence suggests that consumption of antioxidant vitamins may reduce the risk of certain forms of cancer. However, the FDA has determined that this evidence is limited and not conclusive.”
“The conclusions reached in some studies support, while those from other studies contradict the premise of the [qualified health claim]—that consumption of antioxidant vitamins reduces the risk of certain forms of cancer,” CRN wrote in its comment. “Taking into account the number of studies concluding a beneficial effect with those concluding no effect, or harm in some cases, the quality of the studies and the heterogeneity of the study designs, there is a virtual ‘deadlock’ between support and contradiction of the claim.”
The problem with a lot of the studies examining the use of antioxidants with various cancers, Shao noted, is that the data, in most cases including older or cancer-diagnosed populations, cannot be extrapolated to a healthy population. “A lot of the [randomized, controlled trials] using antioxidant vitamins have been done in patients with heart disease already [for example], or with cancer already,” he said. “So the needle hasn’t moved. Hasn’t gotten any worse; hasn’t gotten any better. So our recommendation is don’t change [the qualified health claim]; it’s not warranted.”
Despite this deadlock, there is one area of research where an antioxidant, specifically vitamin E, has been consistently found to be beneficial in the prevention of one cancer, specifically prostate cancer. “Relevant observational trials included a cross-sectional study and several prospective trials demonstrating an inverse relationship between vitamin E intake from diet or supplementation and/or serum levels and prostate cancer risk,” CRN wrote. “In a large prospective RCT, supplementation with vitamin E, along with several other antioxidants, including vitamin C, resulted in a significant reduction in prostate cancer risk.” However compelling the suggested link is, however, there is no conclusive data that would warrant a qualified health claim for vitamin E, the supplement association stated.
Selenium
Qualified health claim: “Selenium may reduce the risk of certain cancers. Some scientific evidence suggests that consumption of selenium may reduce the risk of certain forms of cancer. However, the FDA has determined that this evidence is limited and not conclusive.”
Based on the studies evaluated by CRN, while no body of studies either discount or strengthen the observational link between selenium supplementation and a reduction in cancer risk, the FDA might consider coupling selenium and other antioxidants under one antioxidant qualified health claim banner. “If an adjustment of some kind must be made, the agency should consider adding a claim for combined antioxidants, which might include antioxidant vitamins, selenium and carotenoids, such as lutein, lycopene and beta-carotene,” CRN stated.
The one claim currently being evaluated by the FDA that CRN did not comment on concerned dietary fat—specifically that diets low in saturated fat and cholesterol “may” or “might” reduce the risk of heart disease.