Ginkgo biloba, commonly known as ginkgo, is a tree species native to China and one of the oldest living plants on our planet. Its existence traces back approximately 200 million years, earning the title of a “living fossil.” Humans have used ginkgo medicinally for centuries for various health conditions, where it is most well-known for its role in supporting brain health. However, recent research sheds light on its potential role in supporting ocular health. 

Ginkgo contains 60 bioactive compounds, and about 30 of them can only be found in the ginkgo plant. The two primary compound groups are flavonoids and terpenoids, such as ginkgo flavonol glycosides and terpene lactones. Due to these compounds, ginkgo demonstrates neuroprotective and antioxidant properties, and the ability to help promote neurotransmitter balance, support healthy inflammatory responses, and attenuate the adverse effects of oxidative stress. 

Promoting antioxidant status is particularly relevant to eye health, as the retinal photoreceptors are highly susceptible to oxidative and free radical damage caused by light exposure. Moreover, ginkgo may be clinically relevant to those with age-related macular degeneration (AMD) due to its ability to help neutralize free radicals in the cellular membrane.

Studies show that ginkgo biloba can support eye health by promoting healthy blood circulation. The retina is incredibly metabolically active and relies on vascular health to function optimally. Thus, research in recent decades has investigated ginkgo’s potential role in supporting those with ischemic conditions, such as retinal vascular occlusion, diabetic retinopathy, vascular dysregulation, and atherosclerotic changes. 

Impaired blood flow to the optic nerve is a characteristic of individuals with normal tension glaucoma (NTG). A randomized, placebo-controlled, double-masked crossover trial with 27 patients with NTG administered 40 mg of ginkgo three times a day for four weeks, followed by an eight-week washout period, then four weeks of placebo treatment, or vice versa. After receiving the ginkgo treatment, the patients displayed significant improvements in preexisting visual field indices and improved ocular blood flow. 

Similar results are demonstrated in numerous other small clinical trials. Another randomized, double-blinded, placebo-controlled crossover study (n = 45) showed that those receiving ginkgo supplementation for one month had improved biomarkers of ocular blood flow within retinal and retrobulbar vascular beds compared to placebo. Thirty patients with NTG taking ginkgo supplementation (80 mg two times daily for four weeks) demonstrated statistically significant increased ocular blood flow, volume, and velocity compared to placebo. Patients with glaucoma (n = 11) who were given ginkgo supplementation (40 mg three times daily) for only two days exhibited significantly increased ophthalmic artery end-diastolic velocity as measured by color Doppler imaging.

Lastly, a long-term study of 42 patients evaluated the effects of ginkgo oral supplementation (80 mg two times daily) on the progression of visual field defects in patients with NTG. The mean follow-up period was 12.3 years. The patients showed significant improvements in visual field indices, especially in zone 1, which corresponds to the superior central field. 

Much remains to be learned about the potential role of Ginkgo biloba in ocular health. However, it shows promise in supporting the normal functioning of the retina, vision, and ocular blood flow. 

By Danielle Moyer Male, MS, CNS, LDN