The US Food and Drug Administration (FDA) has said it could allow the use of certain – very qualified – health claims linking selenium intake to a reduced risk of bladder, prostate and thyroid cancer.
However, the agency said credible scientific evidence for these benefits is “very limited”, and the claims would therefore need to contain significant qualifying language. For example, the prostate claim would have to include the statement that selenium is “highly unlikely” to reduce the risk of prostate cancer.
The comments came in a letter to attorney Jonathan Emord, in response to a petition filed last year, which had requested that FDA allow qualified health claims for selenium from dietary supplements and a reduced risk of certain site-specific cancers.
In its response sent on June 19, FDA said it “intends to consider exercising its enforcement discretion” for qualified health claims for prostate cancer, bladder cancer and thyroid cancer, but rejected proposed claims for a reduction of other types of cancer.
The health claims proposed by FDA are unlikely to be adopted by industry due to the lengthy qualifying language they contain.
The agency said it will consider the use of the following claims if a supplement contains 14 micrograms or more, which corresponds to 20 percent of the reference daily value (70 micrograms):
Prostate cancer: “Two weak studies suggest that selenium intake may reduce the risk of prostate cancer. However, four stronger studies and three weak studies showed no reduction in risk. Based on these studies, FDA concludes that it is highly unlikely that selenium supplements reduce the risk of prostate cancer.”
Bladder cancer: “One study suggests that selenium intake may reduce the risk of bladder cancer in women. However, one smaller study showed no reduction in risk. Based on these studies, FDA concludes that it is highly uncertain that selenium supplements reduce the risk of bladder cancer in women.”
Thyroid cancer: “One weak, small study suggests that selenium intake may reduce the risk of thyroid cancer. Based on this study, FDA concludes that it is highly uncertain that selenium supplements reduce the risk of thyroid cancer.”
FDA said there is “no credible evidence” to support qualified health claims for selenium dietary supplements and a reduced risk of urinary tract cancers other than bladder cancer, lung and other respiratory tract cancers, colon and other digestive tract cancers, brain cancer, liver cancer, or breast cancer.
To access FDA’s letter, click here .
More work to do
Daniel Fabricant Ph.D, vice president of scientific and regulatory affairs at the supplements trade group Natural Products Association (NPA), said the claims are “not very useful”.
“I can’t see why anyone would want to use these claims. The longer and more qualified the claims get, the less a consumer will pay attention to them,” he told NutraIngredients-USA.com.
However, he added that this is yet more evidence from FDA that the supplements industry needs to be prepared to meet stringent scientific requirements.
“FDA has made it clear that we’ve got some additional work to do in terms of supporting evidence for health claims.”