Too many people have recently experienced the eerie loss of their sense of smell due to coronavirus. Ginkgo biloba appears to be a safe and natural herb to regain what was lost

The Ginkgo biloba tree -- also called the Maidenhair Tree -- was mentioned in the Chinese Materia Medica 5,000 years ago. Fossil records show that the Ginkgo genus is the oldest tree alive in the world, dating back 250 million years to the Permian period. Today, only one species, G. biloba, has survived.^[i]

The ginkgo tree gets its name from the Japanese word "ginkyo," which means "silver apricot" -- the color of ginkgo nuts. The ginkgo tree can live more than 1,000 years and persists in low light, with few nutrients, and is highly resistant to bacteria, fungi and viruses.

Furthermore, its resistance to air pollution has made G. biloba a popular roadside tree in urban areas around the globe. The male leaves of the tree are divided into two distinct lobes, giving us the name biloba.^[ii]

It is no wonder that the "long-living" and hardy Ginkgo biloba tree has also given us a wonderful ancient herb that has extraordinary healing properties. Ginkgo has a long history of use in treating memory issues,^[iii] cognitive impairments^[iv],[v] and improving blood circulation.^[vi] Ginkgo may help treat dementia -- vascular dementia,^[vii],[viii] Alzheimer's disease^{[ix],[x],[xi]} and Parkinson's disease^[xii],[xiii] -- and impacts a range of neurological symptoms.^[xiv],[xv]

It may also protect memory in older adults and its antioxidant ability can protect you from harmful particles called free radicals that build up as you age. It may also help to prevent development of heart disease, cancer and various neurological disorders.^{[xvi],[xvii],[xviii]} Amazingly, it may also restore a person's sense of smell -- the focus of this article.

Sense of Smell (Anosmia)

The term anosmia refers to the total or partial loss of sense of smell. Anosmia may be caused by an infection -- cold, sinus infection, virus or flu -- by a blockage from nasal polyps and, most recently, is known as a common symptom of COVID-19. In most instances, treating the underlying cause of anosmia can restore your sense of smell.^[xix] Current research has determined that coronavirus may cause smell dysfunction, but it doesn't cause permanent anosmia.^[xx]

Coronavirus infections are neuroinvasive and can provoke injury to the central nervous system and long-term illness consequences. This virus has been associated with inflammatory processes due to cellular oxidative stress and an imbalanced antioxidant system.

The ability of phytochemicals with antioxidant and anti-inflammatory activities, such as Ginkgo biloba, to alleviate neurological complications and brain tissue damage has attracted strong ongoing interest in the management of long COVID. Ginkgo biloba extract contains several powerful bioactive ingredients including bilobalide, quercetin and ginkgolides A-C, to kaempferol, isorhamnetin and luteolin.

Ginkgo biloba's anti-apoptotic, antioxidant and anti-inflammatory properties impact cognitive function, memory and other illness conditions such as loss of smell, depression and fatigue found in long COVID.

While preclinical research on the antioxidant therapies for neuroprotection has shown promising results, the advantages of nanotherapies using nanoparticle drug delivery approaches can overcome the challenges of insufficient dosing, limited bioavailability, restricted transport to the central nervous system, transient retention, and low antioxidant capacity to completely scavenge free radicals and unlock the beneficial effects of ginkgo.^[xxi]

In a systematic screening review of the inhibitory potential of 80 herbal products against COVID-19, ginkgo extract was found to exhibit the most potent coronavirus inhibition activities with its ginkgolic acids and bioflavones -- also known as flavonoids, the natural pigments that give vegetables and fruits their color. Further research is recommended using these compounds to develop novel anti-COVID-19 medications or agents through in vitro and in vivo experiments to prevent future outbreaks and remedy long-lasting symptoms.^{[xxii],[xxiii]}

The sense of smell is important to overall health and nutrition since diminished sensations can lead to poor appetite and malnutrition, especially in the elderly. An altered sense of smell may pose other health-related problems, such as accidentally eating rancid foods, because those affected are unable to detect odors that signal spoilage. Those with anosmia may also be unaware when they are breathing toxic, polluted or smoke-filled air.^[xxiv]

Olfactory dysfunction -- loss of the sense of smell -- is a relatively common smell disorder. About 22% of the population experience some loss^[xxv]-- that is often under-recognized by both patients and clinicians. It occurs more frequently as people age and decreases patients' quality of life, often affecting emotion and memory functions.^[xxvi]

Glucocorticoids -- a special class of corticosteroids -- are considered the preferred medical treatment option for olfactory dysfunction (OD).^{[xxvii],[xxviii],[xxix]} Glucocorticoids are powerful medicines that fight inflammation and work with your immune system to treat a wide range of health problems.

A glucocorticoid is a kind of steroid. For example, prednisone and dexamethasone are two common drugs used to ease inflammation associated with allergies and viral and respiratory infections.^[xxx] Even before COVID-19, people who had viral infections were losing their sense of smell.

In a 2017 study of 42 patients diagnosed with post viral OD, all patients took two olfactory tests, including Taste-Threshold Test (T&T test) and Sniffin Sticks test before and after treatment. The treatment was taken up to three months until effective with the results of olfactory tests recorded monthly. Twenty patients took prednisone acetate, a glucocorticoid in the first treatment group.

T&T test showed that the effective and improvement rate of the prednisone acetate treatment were 25% and 45%, respectively; Sniffin Sticks test showed that the effective and improvement rate of the treatment were 20% and 50%, respectively.

Twenty-two patients received the combined treatment of the ginkgo biloba extract with the glucocorticoid. T&T test showed that the effective and improvement rate of the gingko treatment with prednisone were 32% and 50%, respectively; the Sniffin Sticks test showed that the effective and improvement rates of the combined treatment were 27% and 55%, respectively.

In the patients with post-viral OD who took the two therapies together, the sense of smell was improved significantly. The effect of the combination of ginkgo biloba extract with prednisone acetate outperformed the effect of prednisone acetate alone. Prolonged duration of treatment is helpful for the recovery of olfaction.^[xxxi]

In a 2009 study of 71 patients diagnosed with post-viral olfactory loss following sinus inflammation, all participants were treated with prednisolone for two weeks and used a steroid called mometasone nasal spray twice daily for four weeks as well. In addition, 43 subjects received 80 milligrams per day (mg/day) of ginkgo biloba three times a day for four weeks.

The subjects took two olfactory function tests -- butanol threshold test (BTT) and the cross-cultural smell identification test (CCSIT) -- at the beginning of the study and at the end of the four-week treatment period to test their sense of smell. Both treatments worked but the combined treatment was superior. Ginkgo improved the ability of the glucocorticoid and steroid treatments to restore the sense of smell following upper respiratory viral infection.^[xxxii]

Similarly, in an anosmia mouse study, 25 mice were divided into one control group without anosmia and four anosmia treatment groups (given treatments of dexamethasone and/or ginkgo biloba). The effects of treatment were evaluated by behavioral test, Western blot and immunohistochemistry two weeks after 3-MI injection. Sense of smell was significantly recovered by combination treatment of dexamethasone and ginkgo biloba, particularly effective when oxidative stress is maximized by dexamethasone.^[xxxiii]

Associated Deficits

Researchers believe the loss of smell and taste may be the earliest symptoms and could be important markers to diagnose and treat COVID-19 infections. In their meta-analysis, over 52% of the 1,627 patients with COVID-19 experienced olfactory loss -- sense of smell -- in their analysis of 10 studies and more than 43% of 1,390 subjects had gustatory dysfunction -- taste impairment -- in a total of nine studies reviewed^[xxxiv]

Loss of smell often accompanies cognitive deficits, depression,^[xxxv] fatigue and other long-haul COVID symptoms. Cognitive symptoms persisting longer than three months after a viral infection, such as memory loss or difficulties concentrating, have been reported in up to one-third of patients after COVID-19. Overall, patients with sense of smell loss often report higher social isolation, lower quality of life,^[xxxvi] more depressive symptoms and have a higher mortality.^{[xxxvii],[xxxviii]}

In case studies of three women and two men, aged 26 to 59 years who presented with concentration and attention deficits, cognitive deficiencies and/or fatigue nine to 35 weeks after a COVID-19 infection, an 80-mg dose of ginkgo biloba extract (EGb 761) twice daily substantially improved or completely restored cognitive deficits and symptoms such as fatigue and loss of smell, within six months.^[xxxix]

In previous studies, EGb 761 was shown to protect endothelial cells, to have potent anti-inflammatory effects and to enhance neuroplasticity, which could explain its ability to help with cognitive disorders.^[xl]

In fact, the administration of EGb761 at 120 mg/day led to a significant improvement of cognitive decline/dysfunction, memory, activities of daily living and depression in 500 subjects with mild cognitive impairment (MCI) over 24 months.^[xli] Meta-analytic findings suggested overall benefits of EGb 761 for stabilizing or slowing decline in cognition of subjects with cognitive impairment and dementia or Alzheimer's disease as well.^{[xlii],[xliii]}

In an eight-year longitudinal study of 2,125 participants starting with a group of healthy older adults ages 70 to 73, 48% of participants had a normal sense of smell, 28% showed a partial loss of smell and 24% had a profound loss of the sense. With follow-up testing every six months for eight years, 25% of participants developed significant depressive symptoms.

The worse a person's sense of smell, the higher their depressive symptoms, even after adjusting for age, income, lifestyle, health factors and use of antidepressant medication. This study suggests that olfaction and depression may be linked through both biological -- altered serotonin levels, brain volume changes and behavioral -- reduced social function and appetite -- mechanisms.^[xliv]

Ginkgo Biloba Improves Smell and Linked Health Deficits

Ginkgo biloba is an amazing natural remedy made from the oldest living fossil tree and its leaves. To treat dementia, cognitive issues, depression, mood and anxiety disorders, inflammation and oxidative stress-related diseases, fatigue and other long-COVID symptoms and to restore our sense of smell and quality of life, ginkgo biloba is a safe and effective treatment option.

Please see GreenMedInfo.com for in-depth research on the topics of ginkgo biloba, olfaction disorders and smell disorders.

References

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