CSPI is urging FDA to prohibit the use of ginkgo in foods and dietary supplements, citing a report from the National Toxicology Program on the ingredient that claimed to have found “clear evidence” that ginkgo caused liver cancer in mice and “some evidence” that it caused thyroid cancer in rats.
But industry groups, including the American Herbal Products Association, sharply criticized the NTP report for using a ginkgo extract that did not accurately represent what was available in the market.
Extract used was ‘outlier’
Steven Dentali, AHPA’s chief science officer, generated a graph for use in his comments on the draft version of the NTP report to help quantify how different the test material was from ginkgo extracts available in the market. Most ginkgo extracts plotted on the graph had a 30% or lower concentration of flavonol glycosides and none, outside of the test material, had a terpene lactone concentration that exceeded about 11%. The study material, at 31.2% and 15.4% respectively, was in a category by itself, with values that were literally off the chart, Dentali said.
“I had to add a quadrant just to fit it in. This is an outlier,” Dentali told NutraIngredients-USA.
The NTP stated in the report that the extract was representative of what was available in the market.
“It’s not correct if they are trying to say that this is representative. They say that this is similar to products in the market. Well, elephants are similar to mice. They both have four legs,” Dentali said.
The final version of the NTP report did not include Dentali’s chart. Dentali had recommended in his comments that the final version of the report be amended to make it clear that the results pertained to a specific ginkgo extract, not to commonly available ginkgo products as a whole.
“Their study results are specific to the material they studied. Had this gone through a peer review process at the National Center for Complementary and Alternative Medicine claiming that this material was representative it would have been rejected,” Dentali said.
Not scientifically valid
“Ginkgo biloba has literally been used for thousands of years, and this attempt by CSPI to discredit this safe and beneficial dietary supplement demonstrates an irresponsible misinterpretation of both the science and the intent of the National Toxicology Program (NTP) in reviewing ginkgo. This premature evaluation from CSPI reveals an abuse of its position, a lack of understanding about the regulation of food by FDA, and presents a true disservice to consumers," said Steve Mister, president and CEO of the Council for Responsible Nutrition.
Mister noted that in FDA's response to the CSPI request, the agency said, "…it is not scientifically valid to conclude with certainty that dietary supplement products containing Ginkgo biloba are unsafe based solely on data from the new NTP study. In the study, rats and mice were fed amounts of Ginkgo biloba extracts (by body weight) that may be considerably greater from those which a consumer would normally ingest from a dietary supplement product containing Ginkgo biloba. In addition, there may be differences in the extract used in these studies in contrast to what is available on the market for Ginkgo biloba dietary supplements."
These considerations did not sway the CSPI, which sounded the alarm bells.
“This is typical CSPI alarmism and demagoguery,” said Marc Ullman, an attorney with the firm Ullman, Shapiro & Ullman who represents dietary supplement companies.
“The NTP didn’t test what was available in the market. They did the same thing with aloe. It looks like there is a very disturbing trend at NTP to justify their existence by announcing that they have found things that cause cancer,” Ullman said.