Concerns Over Ginkgo Biloba and Cancer Risk
Overview of Ginkgo Biloba Use
Recent studies involving mice have raised concerns about the potential carcinogenic effects of Ginkgo biloba consumption. In light of these findings, researchers in Italy have conducted a study to assess the safety of Ginkgo biloba in human use. Traditionally, the leaves and seeds of Ginkgo biloba have been utilized for thousands of years to treat respiratory and cardiovascular conditions. Today, Ginkgo biloba leaf extract (GBLE) is among the most widely used supplements globally, particularly for cognitive impairment.
Mechanisms of Action
The therapeutic effects of GBLE on memory have several proposed mechanisms. These include antioxidant activity, inhibition of caspase-3 activity, and anti-amyloid activity. Additional mechanisms such as the inhibition of platelet activation and modulation of neurotransmitter pathways have also been suggested.
Does Ginkgo Biloba Cause Cancer?
Current Research Findings
Generally, Ginkgo biloba is well-tolerated, with minimal evidence of adverse drug reactions. However, a report from the US National Toxicology Program indicated that GBLE might be carcinogenic in mice, as these rodents exhibited a higher incidence of thyroid and liver cancers. This finding is unexpected, as prior studies have not provided substantial evidence for carcinogenicity in humans. To address this concern, a research team in Rome conducted a study to evaluate the clinical and genomic safety of Ginkgo biloba, which was published in BMC Complementary and Alternative Medicine earlier this year.
Study Design and Methodology
In this multi-center randomized trial, 47 elderly residents of nursing homes received either oral doses of Ginkgo biloba or a placebo twice daily for six months. Participants were assessed at both the beginning and end of the study for adverse reactions, liver injury, and DNA damage. Additionally, several genomic assays were performed to analyze the expression of c-myb, p53, and ctnnb, which are linked to various cancers when mutated.
No Significant Risks Identified
At the conclusion of the treatment period, participants who took GBLE exhibited no markers of adverse reactions or liver injury. The level of DNA damage, assessed through micronuclei and alkaline comet assays, showed no significant difference between the treatment and placebo groups. Similarly, there was no notable difference in the expression of the three genes analyzed between the two groups.
Study Benefits and Challenges
This study provided a thorough assessment of potential risk factors associated with Ginkgo biloba treatment by measuring multiple markers of clinical and genomic safety. Enrolling elderly nursing home residents offered two key advantages: it allowed for better standardization of diets over the long term and provided clinical data from a demographic often overlooked in clinical safety studies. However, challenges arose as more participants than anticipated withdrew from the study due to advanced age.
Conclusion
Overall, the study demonstrated no significant clinical or genomic risks linked to Ginkgo biloba consumption after six months of treatment. The authors advocate for similar multiple endpoint analyses in future research involving conditions with both clinical and genomic aspects.
Reference
Bonassi et al. Clinical and genomic safety of treatment with Ginkgo biloba L. leaf extract (IDN 5933/Ginkgoselect®Plus) in elderly: a randomised placebo-controlled clinical trial [GiBiEx]. BMC Complement Altern Med. 2018 Jan 22;18(1):22. doi: 10.1186/s12906-018-2080-5.