The Center for Science in the Public Interest (CSPI) has urged consumers to avoid supplements made with ginkgo biloba, which they warn are often adulterated and have been shown to be ineffective in improving memory and circulation.
The nonprofit nutrition and food safety watchdog group is also calling on the Food and Drug Administration (FDA) to use its enforcement authority to seize adulterated pills in the marketplace.
Six of 10 ginkgo supplements analyzed this year by the independent supplement testing organization ConsumerLab.com failed quality tests; the pills had far less ginkgo than advertised or they showed evidence of having been spiked with cheaper plant material. The American Botanical Council (ABC), the American Herbal Pharmacopoeia and the University of Mississippi’s National Center for Natural Products Research concluded earlier this year that economically motivated adulteration of ginkgo extracts is an ongoing problem in the dietary supplement industry.
“Even if people choose to overlook the evidence that ginkgo does not supply the benefits that its manufacturers claim, all supplement consumers need to know that it’s anyone’s guess how much, if any, ginkgo is in a given pill,” said CSPI regulatory affairs director Laura MacCleery. “The FDA should take enforcement action to protect consumers from wasting their money on pills that don’t do what they claim to do, and that may not even be what they claim to be.”
The leaves of the ginkgo tree are expensive, and a large quantity of leaves is needed to produce ginkgo extracts. Unscrupulous manufacturers have used inexpensive buckwheat extract or other plant extracts which contain a chemical that can fool simple tests for ginkgo, to augment or replace more-expensive ginkgo, according to the ABC. “Industry experts agree that the adulteration of ginkgo extracts is intentional,” said Stefan Gafner, the council’s chief science officer, in a monograph on ginkgo.
In a six-year National Institutes of Health (NIH)-funded study of more than 3,000 participants aged 75 and over, those given authentic ginkgo were just as likely to develop dementia as those given a placebo. Among participants who did not develop dementia, those taking ginkgo were no less likely than those taking the placebo to experience declines in memory, use of language, visuospatial abilities or executive function. And a 2013 Cochrane Collaboration review found that ginkgo failed to help those who had poor circulation in their legs walk longer.
In its letter filed in May with the FDA’s Office of Dietary Supplement Programs, CSPI said that the agency should consider warnings on packages of ginkgo. The NIH cautions that ginkgo can cause bleeding in pregnant women, the elderly and other people with a known risk of bleeding.
In December 2017, CSPI urged the FDA and the Federal Trade Commission (FTC) to take enforcement action against companies claiming that their dietary supplements can help ease the symptoms of withdrawal from opioid pain medication. In January, the FDA and the FTC notified 12 companies that they must stop making those kinds of treatment claims.