CSPI Calls for FDA Enforcement Action Against Adulterated Ginkgo Extract Products

In a letter signed by Laura MacCleery, Director of Regulatory Affairs for the Center for Science in the Public Interest (CSPI), the consumer advocacy group requested the US FDA to act against the sale of adulterated ginkgo leaf extract products.¹ The letter was prompted by a ConsumerLab investigation, which failed six out of 10 ginkgo products in their 2018 ginkgo report,² and by the review of published data on ginkgo leaf extract adulteration issued by the Botanical Adulterants Prevention Program in January, 2018.³ The letter to Steven Tave, Director of the Office of Dietary Supplements Programs at the FDA, also suggested that while ginkgo benefits were not supported by adequate published clinical evidence, ginkgo intake was not without risks to a patient’s health. The safety concerns, which relate to a potentially increased risk of bleeding in certain populations (older people, pregnant woman, and those with a higher risk of bleeding) using ginkgo extract preparations, are based on cautionary statements listed on the National Center of Complementary and Integrative Health’s (NCCIHs) ginkgo web page.⁴ However, a systematic review and meta-analysis of 18 clinical trials with 1985 patients did not find any difference in the risk of bleeding between patients taking ginkgo leaf extracts and those taking placebo.⁵

Comment: There have been numerous publications that have documented the problems with the quality and authenticity of commercial ginkgo dietary supplements. The request for more enforcement action by the FDA to remove adulterated products from the market is therefore understandable and justified. However, CSPI’s claims that ginkgo dietary supplements actually do more harm than good are far from accurate. Two out of three systematic reviews looking at the impact of ginkgo leaf extracts on the cognitive function in patients with Alzheimer’s disease suggested that cognitive decline in patients using ginkgo extracts slowed down compared to those using placebo.^6-8 Small improvements in the pain-free walking distance in patients with peripheral arterial disease using ginkgo extracts were also shown in a systematic review of clinical trials.⁹ The second edition of the American Herbal Products Association’s Botanical Safety Handbook (BSH) classifies ginkgo as safe when used appropriately (safety class 1) and states that ginkgo leaf is generally well-tolerated, with adverse effects noted in clinical trials being similar to those in subjects taking a placebo.¹⁰ There is a cautionary statement in BSH on possible interactions between ginkgo and anticoagulant drugs, although a review on the topic suggests that this interaction risk is low at the standard dose of 240 mg extract/day or lower.^10,11

References

1.     MacCleery L letter to Tave S. May 18, 2018. Available at: https://cspinet.org/sites/default/files/attachment/ginkgo-letter-fda-final.pdf. Accessed June 4, 2018.

2.     Finding Real Ginkgo Isn’t Easy, ConsumerLab’s Tests Reveal [press release]. White Plains, NY: ConsumerLab.com; March 7, 2018.

3.     Gafner S. Adulteration of Ginkgo biloba leaf extract - Botanical Adulterants Bulletin. Austin, TX: ABC-AHP-NCNPR Botanical Adulterants Prevention Program. 2018;1-8. http://cms.herbalgram.org/BAP/BAB/GinkgoBulletin.html. Accessed June 4, 2018.

4.     Ginkgo. Bethesda, MD: National Center for Complementary and Integrative Health. 2016. Available at: https://nccih.nih.gov/health/ginkgo/ataglance.htm. Accessed June 29, 2018.

5.     Kellermann AJ, Kloft C. Is there an increased risk of bleeding with standardized Ginkgo biloba extract therapy? A systematic review and meta-analysis. Pharmacotherapy. 2011;31(5):490-502.

6.     Birks J, Grimley Evans J. Ginkgo biloba for cognitive impairment and dementia. Cochrane Database Syst Rev. 2009;1

7.     Janssen IM, Sturtz S, Skipka G, Zentner A, Velasco Garrida M, Busse R. Ginkgo biloba in Alzheimer's disease: a systematic review. Wien Med Wochenschr. 2010;160(21–22):539–546

8.     Tan M-S, Yu J-T, Tan C-C, Wang HF, Meng XF, Wang C, Jiang T, Zhu XC, Tan L. Efficacy and adverse effects of Ginkgo biloba for cognitive impairment and dementia: a systematic review and meta-analysis. J Alzheimer’s Dis. 2015;43:589–603.

9.     Nicolaï SPA, Kruidenier LM, Bendermacher BLW, Prins MH, Stokmans RA, Broos PPHL, Teijink JAW. Ginkgo biloba for intermittent claudication. Cochrane Database Syst Rev. 2013, Issue 6. Art. No.: CD006888.

10. Gardner Z, McGuffin M, eds. American Herbal Products Association’s Botanical Safety Handbook. 2nd ed. Boca Raton, Florida: CRC Press; 2013:407-413.

11. Gurley BJ, Fifer EK, Gardner Z. Pharmacokinetic herb-drug interactions (part 2): Drug interactions involving popular botanical dietary supplements and their clinical relevance. Planta Med. 2012;78:1490-1514.