Three time-tested supplements stand out as champions for eye and brain health: garlic, ginseng, and ginkgo. Research on these supplements backs up why they have been used for thousands of years. Garlic plays an important role in all three major traditional medicines–Traditional European Herbal Medicine, Ayurveda, and Traditional Chinese Medicine. Ginseng and ginkgo are crucial herbs in Traditional Chinese Medicine. Do these supplements work? Are they beneficial for aging brains and eyes? What does the research show?
Brain and eye health are closely connected. The optic nerve of the eye is actually neural tissue. Heart and cardiovascular health are also closely tied to the brain and eyes. Oxidative stress can damage all three systems. What role could garlic, ginseng, and ginkgo play in counteracting diseases such as dementia, cataracts, macular degeneration, and glaucoma?
Diabetic Retinopathy & Diabetic Cataracts
Diabetic retinopathy is common in diabetes, often resulting in retinal damage if left untreated. North American Ginseng research found benefits for the retina in diabetic rodents. Also, the heart and circulatory systems were protected. The main reason was likely ginseng’s antioxidant properties.1
Cataracts are a common side-effect of diabetes. The partial or main reason is glycation, the accelerated binding of sugar and protein molecules in the lens. Ginkgo biloba extract was found to have a protective effect on diabetic cataracts in the laboratory.2
Glaucoma is a serious eye disease that usually strikes seniors. Most glaucoma patients have elevated intraocular pressure in the eye. Some glaucoma patients have normal or low-tension glaucoma. Regardless, glaucoma if left untreated damages the optic nerve and other parts of the eye. Glaucoma leads to tunnel vision and may cause near or total blindness. Even with treatment and reduced or normal intraocular pressure, glaucoma may continue to progress. This can be due to poor circulation and lack of essential nutrients reaching the optic nerve.
A 2012 review looked at ginkgo and glaucoma.3 Vitamins C and E, for example, are antioxidants. However, antioxidants in ginkgo called “polyphenolic flavonoids” can act on the mitochondrial level. The mitochondria are like batteries for cells. Malfunctioning mitochondria are present in several diseases, especially neurodegenerative diseases. Studies have found damaged mitochondria in glaucoma patients.4 Oxidative damage to the mitochondria likely plays a role in glaucoma. Thus, ginkgo may prove helpful as an adjunct therapy.
Glutathione — also called “the anti-aging antioxidant” — is a cellular detoxifier and broad-spectrum antioxidant. The body produces glutathione. However, it requires the “building blocks,” including several amino acids, selenium and Vitamin C. Our diets tend to have insufficient L-cysteine, which is one of the building blocks. Additionally, pollution, poor diet, a sedentary lifestyle, toxins, stress, infections, aging, and more can reduce glutathione levels. Glaucoma patients have low glutathione levels, according to several studies.5 6 Research has found that garlic can raise glutathione levels in the body. 7 8
In the laboratory, researchers can induce cataracts by injecting rodents with a mineral. In a small but well-controlled study, a group of rats were injected with both the mineral and a garlic extract solution.9 The control groups had no treatment, the mineral, or the garlic. Rats injected with only the mineral developed cataracts as expected. None of the other groups developed cataracts. Therefore, garlic may be a useful herbal remedy for preventing the formation of cataracts.
After an eye wound or corneal surgery, the cornea needs time to heal. An animal study found that a derivative of ginseng promotes corneal wound healing.10 Applying ginseng gintonin eyedrops to rabbits with corneal damage promoted rapid recovery. Corneal cells died at a slower rate, and new corneal cells proliferated.
Dementia and Alzheimer’s Disease
A 2010 review of research on ginkgo biloba and Alzheimer’s disease found that ginkgo was better than a placebo.11 Another study found that ginkgo appeared to delay the onset of Alzheimer’s disease.12 Garlic is being researched for its neuroprotective properties.13 And research into ginseng is finding many neuroprotective benefits.14
How Much to Ginkgo, Ginseng & Ginger Take or Eat
Blood Thinning Warning: All three of these products can thin the blood. This means they can reduce the blood’s ability to clot. For people who are not taking blood thinners, this blood-thinning effect could prevent a stroke. However, if you are taking a blood-thinning medication such as warfarin (Coumadin), talk to your doctor before taking these supplements. Also disclose all your supplements if you need surgery.15 These same guidelines apply to eating or drinking large quantities of garlic.
These products can be eaten as an ingredient in cooking, or taken in various supplemental forms. Michael Edson, co-founder of Natural Eye Care, will recommend these daily dosages in his upcoming book about Natural Brain Health, and discussed in his and Dr. Grossman’s recent book “Natural Eye Care: Your Guide to Healthy Vision and Healing“:
- Garlic (optimized) – 1200 mg per day
- Ginseng (Panax) – 500mg – 1,000 mg per day of Asian ginseng (panax ginseng) extract (root)
- Gingko Biloba- 120mg – 240 mg per day
- Phytother Res. 2013 Feb;27(2):290-8. doi: 10.1002/ptr.4719. Epub 2012 May 8. Preventive effects of North American ginseng (Panax quinquefolius) on diabetic retinopathy and cardiomyopathy. By Sen S et. al. ↩
- Phytother Res. 2014 May;28(5):767-73. doi: 10.1002/ptr.5060. Epub 2013 Sep 2. Preventative effects of Ginkgo biloba extract (EGb761) on high glucose-cultured opacity of rat lens. By Lu Q et al. ↩
- Mol Vis. 2012; 18: 390–402. Published online 2012 Feb 9. PMCID: PMC3283204 PMID: 22355250 Ginkgo biloba: An adjuvant therapy for progressive normal and high-tension glaucoma. By A.K. Cybulska-Heinrich et al. ↩
- Curr Opin Ophthalmol. 2011 Sep; 22(5): 325–331. doi: 10.1097/ICU.0b013e328349419d Mitochondrial Disorders and The Eye. By Samantha A. Schrier and Marni J. Falk ↩
- Researchers: D. Gherghel, H.R. Griffiths, et al. Published: Systemic Reduction in Glutathione Levels Occurs in Patients with Primary Open-Angle Glaucoma, Glaucoma, March, 2005. ↩
- Researchers: D. Gherghel, S. Mroczkowska, et al. Published: Reduction in Blood Glutathione Levels Occurs Similarly in Patients With Primary-Open Angle or Normal Tension Glaucoma, Glaucoma, May, 2013. ↩
- Phytother Res. 2012 Jan;26(1):18-25. doi: 10.1002/ptr.3502. Epub 2011 Apr 28. Aged red garlic extract reduces cigarette smoke extract-induced cell death in human bronchial smooth muscle cells by increasing intracellular glutathione levels. By Jeong YY et al. ↩
- Pak J Biol Sci. 2009 May 15;12(10):765-71. The protective effects of garlic extract against acetaminophen-induced oxidative stress and glutathione depletion. By Anoush M et al. ↩
- J Ocul Pharmacol Ther. 2009 Oct;25(5):395-400. doi: 10.1089/jop.2009.0038. Prevention of selenite-induced cataractogenesis in Wistar albino rats by aqueous extract of garlic. Javadzadeh A et al. ↩
- J Vet Sci. 2017 Sep 30;18(3):387-397. doi: 10.4142/jvs.2017.18.3.387. Gintonin, an exogenous ginseng-derived LPA receptor ligand, promotes corneal wound healing. By Kim HJ et al. ↩
- Effects of Ginkgo biloba in dementia: systematic review and meta-analysis. Weinmann S, Roll S, Schwarzbach C, Vauth C, Willich SN BMC Geriatr. 2010 Mar 17; 10():14. ↩
- GuidAge study: a 5-year double blind, randomised trial of EGb 761 for the prevention of Alzheimer’s disease in elderly subjects with memory complaints. Andrieu S, Ousset PJ, Coley N, Ouzid M, Mathiex-Fortunet H, Vellas B, GuidAge study GROUP. Curr Alzheimer Res. 2008 Aug; 5(4):406-15. ↩
- Garlic reduces dementia and heart-disease risk. Borek C J Nutr. 2006 Mar; 136(3 Suppl):810S-812S ↩
- Van Kampen J.M., Baranowski D.B., Shaw C.A., Kay D.G. Panax ginseng is neuroprotective in a novel progressive model of Parkinson’s disease. Exp Gerontol. 2014;50:95–105 ↩
- National Institutes of Health. Garlic. https://nccih.nih.gov/health/garlic/ataglance.htm accessed 7/31/2019 ↩