Dementia is one of the predominant health problems within populations of advanced age, afflicting 5-10% of individuals with said disease.1 As many as 35.6 million individuals have dementia globally, and it has been estimated that said number will increase to 65.7 million by 2030.1(508) Hence, it is imperative that individuals with such a condition explore options which help control the degenerative process of dementia. As a means of appreciating such protocols, the following will consider Ginkgo biloba (GB), a botanical, in greater detail as well as its relationship to a dominant driver of dementia; Alzheimer’s disease (AD).
Dementia can be defined as an aggregate of symptoms negatively affecting social abilities, thinking, and memory in such a way that impedes an individual’s daily life.2 Other characteristic symptoms of dementia include difficulty communicating, finding words, problem-solving, planning and organizing, as well as increased confusion and disorientation.2 Finally, psychological changes can include depression, anxiety, hallucinations, and agitation all of which can increase in severity over time.2 AD is one of the causes behind dementia and is defined as a neurodegenerative disease characterized by clinical changes (cognitive deterioration) as well as structural changes to include the deposition and accumulation of hyperphosphorylated tau tangles and beta-amyloid plaques.3 Left unmitigated, such neurological degradation systematically strips individuals of function, quality of life, and dignity. However, despite a seemingly unalterable prognosis, evidence suggests interventions, which could help attenuate such changes in the brain to include GB.
GB is a plant whose leaves have been cultivated for use in popular medicines dating back as early 1505 AD.4 Such a plant has been in existence in excess of 200 million years, and has undergone little modification due to its resilience to environmental stressors.4(142) Of particular note is GB’s terpene trilactones such as ginkgolides A, B, C, J, P, and Q, and bilobalides, polyphenols, methylpyridoxine, phenolic acids, alkylphenols, and flavonol glycosides; such phytochemical value of the GB plant has driven its use in traditional Chinese medicine for several millenia.4(141) Due to its widespread use as an alternative intervention in treating respiratory, renal, cardiovascular, and central nervous system disorders, it has gained appeal, and value, estimated at 500 billion dollars (USD).4(145) Of particular interest to this author is the potential application in treating nervous system disorders, such as dementia/AD. Having briefly considered the history, traditional applications, and phytochemical characteristics of GB, the following will review research exploring its utility in managing symptoms related to the aforementioned conditions.
Liu et al5 stated that previous studies outlined the effects of combining G. biloba, a type of glycoside mentioned in the previous section, and donepezil (treats confusion associated with AD) helped attenuate AD symptoms in rat and mice models. However, applicability and meaningful changes within human AD populations remained equivocal with some studies identifying efficaciousness and other studies indicating no effective change in symptoms.5(2) As a means of determining if GB could manage neurotoxicity associated with beta-amyloid plaques generated from AD, Liu et al5(2)conducted a review of large-scale clinical studies in human trials. Said review included studies dating back to the 1980s; trials outlined from Liu et al5(4) included 17 studies indicating beneficial effects of GB on cognition while 11 studies showed negative effects of GB on cognition. The lack of homogenous results were thought to derive from the following: in the negative studies, 9 trials involved young and healthy adults.5(6) However, in the positive studies, 13 clinical trials recruited elderly participants; a group best representing populations in need of intervention.5(6)
Within the 12 studies containing negative results, the duration length was largely short-term (less than 12 weeks) while only 2 studies lasted beyond 22 weeks.5(6) Conversely, 11 studies elucidating positive results were carried out in excess of 22 weeks. Such may suggest that longer-term trials are necessary to produce favorable results in cognition.5(6) Other pertinent differences included dose; within the negative results group, 120 mg or less of GB was used within 7 studies, while ≥240 mg was found in 10 studies with positive outcomes.5(6) Such results serve as a reminder that study design must always be considered when examining outcomes, and when comparing studies. Ultimately, Liu et al5(7) concluded that GB could help improve cognitive function, especially amongst individuals afflicted with mild dementia, though favorable outcomes are likely to emanate from doses of 240 mg GB over 24-week periods. Though findings are encouraging, said researchers emphasized a need for future studies that explored longer trial periods to demonstrate the effectiveness of GB.
Dementia is one of the predominant health problems within populations of advanced age, afflicting 5-10% of individuals with said disease. Over time and with precision, dementia can systematically strip individuals of function, quality of life, and dignity. However, interventions do exist that can support cognitive function and slow such degenerative neurological processes. Implementation of GB has encouraging results and due to its ease of access, cost effectiveness, and relative safety, consideration of such a botanical in helping manage AD is appealing. Most relevantly, using GB as part of a larger protocol to include physical activity, community, unprocessed foods, and improved sleep hygiene is likely to produce a synergistic effect. Ultimately, such an inclusive approach holds the potential to liberate individuals from the influence of AD and associated cognitive decline.
References
1. Charenboon T, Jaisin K. Ginko biloba for prevention of dementia: A systematic review and meta-analysis. J Med Assoc Thai. 2015;98(5):508-513. https://pubmed.ncbi.nlm.nih.gov/26058281/. Accessed June 9, 2020.
2. Dementia: Symptoms and Causes. Mayo Clinic Website. https://www.mayoclinic.org/diseases-conditions/dementia/symptoms-causes/syc-20352013. Accessed June 9, 2020.
3. Wang B, Li W, Fan W, et al. Alzheimer’s disease brain network classification using improved transfer feature learning with joint distribution adaptation.IEEE. 2019:2959-2963. doi: 10.1109/EMBC.2019.8856726.
4. Isah T. Rethinking Ginko biloba L.: Medicinal uses and conservation. Pharmacogn Rev. 2015;9(18):140-148. doi:10.4103/0973-7847.162137.
5. Liu H, Ye M, Guo H. An updated review of randomized clinical trials testing the improvement of cognitive function of Ginko biloba extract in healthy people and Alzheimer’s patients. Front Pharmacol. 2019;10(1688):1-8. doi:10.3389/fphar.2019.01688.
-Michael McIsaac