Blueberries may help protect against age-related macular degeneration, and black currants may help halt the progression of glaucoma.
Dietary Treatment of Glaucoma
Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.
Once we’ve preserved the pigment in our retinal pigment epithelial cells, we need to keep them alive, which may be where anthocyanin phytonutrients come in. Anthocyanins, from the Greek anthos—meaning flower, and kyanos, meaning blue—blue flower—are natural plant pigments that make pansies look purple, and turns green cabbage into purple cabbage, yellow corn into purple corn, brown rice to purple rice, white potatoes to blue potatoes, orange carrots to purple carrots, and turns blueberries into, well, blueberries, and keeps blackberries black.
As we age, our critical RPE layer starts to break down, but we may be able to decelerate that aging with blueberries. Here are human RPE cells in a petri dish exposed to various stressors. The ones bathed in blueberry anthocyanins had fewer free radicals, and a lower proportion of aged cells—suggesting that blueberries and these other red/blue/purple pigmented fruits and vegetables may help prevent age-related macular degeneration. And, blueberries may be especially important for blue eyes, as we saw in an earlier video.
Preventing is nice. But, what if we already have a disease like glaucoma, an incurable eye disease in which our optic nerve, which connects our eyes to our brain, starts deteriorating, and we start losing our visual fields?
A few years ago, Japanese researchers showed they could apparently halt the progression of disease with black currants. They gave people black currants for six months, significantly boosting the blood flow to their optic nerve. The results suggested that black currants might be “a safe and valuable option.” But, it was not double-blind; no control group. So, I didn’t report it when it was initially published, but, here we go! Finally.
Glaucoma patients split into two groups—half got black currants; the other half didn’t— let’s see what happened. Here’s a measure of the deterioration of their visual fields in both groups in the two years leading up to the beginning of the study. Worse; worse; worse—despite taking the best glaucoma drugs on the market. Then the study starts. The berry-free control group continued to worsen. But the berries appeared to stop the disease in its tracks, one year later, two years later. And since there’s no downside, only good side effects to berries, in my opinion, everyone with glaucoma should be eating berries every day.
Please consider volunteering to help out on the site.
- A. Wegner, R. Khoramnia. Cataract is a self-defence reaction to protect the retina from oxidative damage. Med. Hypotheses. 2011 76(5):741 - 744.
- L. Ma, H. L. Dou, Y. Q. Wu, Y. M. Huang, Y. B. Huang, X. R. Xu, Z. Y. Zou, X. M. Lin. Lutein and zeaxanthin intake and the risk of age-related macular degeneration: A systematic review and meta-analysis. Br. J. Nutr. 2012 107(3):350 - 359.
- R. D. Glickman. Ultraviolet phototoxicity to the retina. Eye Contact Lens. 2011 37(4):196 - 205.
- Y. Liu, X. Song, Di Zhang, F. Zhou, D. Wang, Y. Wei, F. Gao, L. Xie, G. Jia, W. Wu, B. Ji. Blueberry anthocyanins: Protection against ageing and light-induced damage in retinal pigment epithelial cells. Br. J. Nutr. 2012 108(1):16 - 27.
- H. Ohguro, I. Ohguro, M. Katai, S. Tanaka. Two-year randomized, placebo-controlled study of black currant anthocyanins on visual field in glaucoma. Ophthalmologica. 2012 228(1):26 - 35.
- K. J. Ciuffreda, B. Vasudevan. Nearwork-induced transient myopia (NITM) and permanent myopia--is there a link? Ophthalmic Physiol Opt. 2008 28(2):103 - 114.
- J. Garrard, S. Harms, L. E. Eberly, A. Matiak. Variations in product choices of frequently purchased herbs: Caveat emptor. Arch. Intern. Med. 2003 163(19):2290 - 2295.
- C. Artaria, R. Pace, G. Maramaldi, G. Appendino. Different brands of bilberry extract: A comparison of selected components. Nutrafoods. 2007 6(4):13-18.
- B. R. Hammond Jr, K. Fuld, D. M. Snodderly. Iris color and macular pigment optical density. Exp. Eye Res. 1996 62(3):293 - 297.
- S. Beatty, I. J. Murray, D. B. Henson, D. Carden, H. Koh, M. E. Boulton. Macular pigment and risk for age-related macular degeneration in subjects from a Northern European population. Invest. Ophthalmol. Vis. Sci. 2001 42(2):439 - 446.
- A. J. Wenzel, C. Gerweck, D. Barbato, R. J. Nicolosi, G. J. Handelman, J. Curran-Celentano. A 12-wk egg intervention increases serum zeaxanthin and macular pigment optical density in women. J. Nutr. 2006 136(10):2568 - 2573.
- B. R. Hammond Jr, E. J. Johnson, R. M. Russell, N. I. Krinsky, K. J. Yeum, R. B. Edwards, D. M. Snodderly. Dietary modification of human macular pigment density. Invest. Ophthalmol. Vis. Sci. 1997 38(9):1795 - 1801.
- C. Y. Cheng, W. Y. Chung, Y. T. Szeto, I. F. F. Benzie. Fasting plasma zeaxanthin response to Fructus barbarum L. (Wolfberry; Kei Tze) in a food-based human supplementation trial. Br. J. Nutr. 2005 93(1):123 - 130.
- P. Bucheli, K. Vidal, L. Shen, Z. Gu, C. Zhang, L. E. Miller, J. Wang. Goji berry effects on macular characteristics and plasma antioxidant levels. Optom Vis Sci. 2011 88(2):257 - 262.
- H. Nakaishi, H. Matsumoto, S. Tominaga, M. Hirayama. Effects of black current anthocyanoside intake on dark adaptation and VDT work-induced transient refractive alteration in healthy humans. Altern Med Rev. 2000 5(6):553-562.
- E. R. Muth, J. M. Laurent, P. Jasper. The effect of bilberry nutritional supplementation on night visual acuity and contrast sensitivity. Altern Med Rev. 2000 5(2):164 - 173.
- E. Perlman. On Too Much of a Good Thing. Med Health R. I. 2011 94(10):309.
- I. Ohguro, H. Ohguo, M. Nakazawa. Effects of anthocyanins in black currant on retinal blood flow circulation of patients with normal tension glaucoma. A pilot study. Hirosaki Med. J. 2007 59:23-32.
Images thanks to Jacob Whittaker, Chatirygirl, Rose Holley, Rick Heath, Bfishadow, Laurel Fan, Rob Qld, suziesparkle, and @rsseattle via flickr; Evan-Amos, Incola, Fir0002, WiseMan42, Stephane8888, and Rasbak via Wikimedia; and the National Eye Institute. Thanks to Ellen Reid for her image-finding expertise, and Jeff Thomas for his Keynote help.
Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.
Once we’ve preserved the pigment in our retinal pigment epithelial cells, we need to keep them alive, which may be where anthocyanin phytonutrients come in. Anthocyanins, from the Greek anthos—meaning flower, and kyanos, meaning blue—blue flower—are natural plant pigments that make pansies look purple, and turns green cabbage into purple cabbage, yellow corn into purple corn, brown rice to purple rice, white potatoes to blue potatoes, orange carrots to purple carrots, and turns blueberries into, well, blueberries, and keeps blackberries black.
As we age, our critical RPE layer starts to break down, but we may be able to decelerate that aging with blueberries. Here are human RPE cells in a petri dish exposed to various stressors. The ones bathed in blueberry anthocyanins had fewer free radicals, and a lower proportion of aged cells—suggesting that blueberries and these other red/blue/purple pigmented fruits and vegetables may help prevent age-related macular degeneration. And, blueberries may be especially important for blue eyes, as we saw in an earlier video.
Preventing is nice. But, what if we already have a disease like glaucoma, an incurable eye disease in which our optic nerve, which connects our eyes to our brain, starts deteriorating, and we start losing our visual fields?
A few years ago, Japanese researchers showed they could apparently halt the progression of disease with black currants. They gave people black currants for six months, significantly boosting the blood flow to their optic nerve. The results suggested that black currants might be “a safe and valuable option.” But, it was not double-blind; no control group. So, I didn’t report it when it was initially published, but, here we go! Finally.
Glaucoma patients split into two groups—half got black currants; the other half didn’t— let’s see what happened. Here’s a measure of the deterioration of their visual fields in both groups in the two years leading up to the beginning of the study. Worse; worse; worse—despite taking the best glaucoma drugs on the market. Then the study starts. The berry-free control group continued to worsen. But the berries appeared to stop the disease in its tracks, one year later, two years later. And since there’s no downside, only good side effects to berries, in my opinion, everyone with glaucoma should be eating berries every day.
Please consider volunteering to help out on the site.
- A. Wegner, R. Khoramnia. Cataract is a self-defence reaction to protect the retina from oxidative damage. Med. Hypotheses. 2011 76(5):741 - 744.
- L. Ma, H. L. Dou, Y. Q. Wu, Y. M. Huang, Y. B. Huang, X. R. Xu, Z. Y. Zou, X. M. Lin. Lutein and zeaxanthin intake and the risk of age-related macular degeneration: A systematic review and meta-analysis. Br. J. Nutr. 2012 107(3):350 - 359.
- R. D. Glickman. Ultraviolet phototoxicity to the retina. Eye Contact Lens. 2011 37(4):196 - 205.
- Y. Liu, X. Song, Di Zhang, F. Zhou, D. Wang, Y. Wei, F. Gao, L. Xie, G. Jia, W. Wu, B. Ji. Blueberry anthocyanins: Protection against ageing and light-induced damage in retinal pigment epithelial cells. Br. J. Nutr. 2012 108(1):16 - 27.
- H. Ohguro, I. Ohguro, M. Katai, S. Tanaka. Two-year randomized, placebo-controlled study of black currant anthocyanins on visual field in glaucoma. Ophthalmologica. 2012 228(1):26 - 35.
- K. J. Ciuffreda, B. Vasudevan. Nearwork-induced transient myopia (NITM) and permanent myopia--is there a link? Ophthalmic Physiol Opt. 2008 28(2):103 - 114.
- J. Garrard, S. Harms, L. E. Eberly, A. Matiak. Variations in product choices of frequently purchased herbs: Caveat emptor. Arch. Intern. Med. 2003 163(19):2290 - 2295.
- C. Artaria, R. Pace, G. Maramaldi, G. Appendino. Different brands of bilberry extract: A comparison of selected components. Nutrafoods. 2007 6(4):13-18.
- B. R. Hammond Jr, K. Fuld, D. M. Snodderly. Iris color and macular pigment optical density. Exp. Eye Res. 1996 62(3):293 - 297.
- S. Beatty, I. J. Murray, D. B. Henson, D. Carden, H. Koh, M. E. Boulton. Macular pigment and risk for age-related macular degeneration in subjects from a Northern European population. Invest. Ophthalmol. Vis. Sci. 2001 42(2):439 - 446.
- A. J. Wenzel, C. Gerweck, D. Barbato, R. J. Nicolosi, G. J. Handelman, J. Curran-Celentano. A 12-wk egg intervention increases serum zeaxanthin and macular pigment optical density in women. J. Nutr. 2006 136(10):2568 - 2573.
- B. R. Hammond Jr, E. J. Johnson, R. M. Russell, N. I. Krinsky, K. J. Yeum, R. B. Edwards, D. M. Snodderly. Dietary modification of human macular pigment density. Invest. Ophthalmol. Vis. Sci. 1997 38(9):1795 - 1801.
- C. Y. Cheng, W. Y. Chung, Y. T. Szeto, I. F. F. Benzie. Fasting plasma zeaxanthin response to Fructus barbarum L. (Wolfberry; Kei Tze) in a food-based human supplementation trial. Br. J. Nutr. 2005 93(1):123 - 130.
- P. Bucheli, K. Vidal, L. Shen, Z. Gu, C. Zhang, L. E. Miller, J. Wang. Goji berry effects on macular characteristics and plasma antioxidant levels. Optom Vis Sci. 2011 88(2):257 - 262.
- H. Nakaishi, H. Matsumoto, S. Tominaga, M. Hirayama. Effects of black current anthocyanoside intake on dark adaptation and VDT work-induced transient refractive alteration in healthy humans. Altern Med Rev. 2000 5(6):553-562.
- E. R. Muth, J. M. Laurent, P. Jasper. The effect of bilberry nutritional supplementation on night visual acuity and contrast sensitivity. Altern Med Rev. 2000 5(2):164 - 173.
- E. Perlman. On Too Much of a Good Thing. Med Health R. I. 2011 94(10):309.
- I. Ohguro, H. Ohguo, M. Nakazawa. Effects of anthocyanins in black currant on retinal blood flow circulation of patients with normal tension glaucoma. A pilot study. Hirosaki Med. J. 2007 59:23-32.
Images thanks to Jacob Whittaker, Chatirygirl, Rose Holley, Rick Heath, Bfishadow, Laurel Fan, Rob Qld, suziesparkle, and @rsseattle via flickr; Evan-Amos, Incola, Fir0002, WiseMan42, Stephane8888, and Rasbak via Wikimedia; and the National Eye Institute. Thanks to Ellen Reid for her image-finding expertise, and Jeff Thomas for his Keynote help.
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Dietary Treatment of Glaucoma
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Content URLDoctor's Note
This is the third of a four-part video series on the latest science on preventing and treating vision loss. In Greens vs. Glaucoma, I detailed the best foods to help prevent glaucoma, and in Dietary Prevention of Age-Related Macular Degeneration, I did the same for age-related macular degeneration—introducing the concept of retinal pigment epithelial cells. In the final installment, Dietary Treatments for Computer Eye Strain, I address dietary interventions for nearwork-induced visual fatigue.
I’ve mentioned anthocyanins before in:
They may be why purple potatoes (Anti-Inflammatory Effects of Purple Potatoes) and purple cabbage may be preferable. Anthocyanins are the pigments in red and purple cabbage that allow for the kitchen chemistry in Testing Your Diet with Pee & Purple Cabbage.
Also, learn about currants in Enhanced Athletic Recovery without Undermining Adaptation.
My previous treatment of glaucoma can be found in Prevent Glaucoma & See 27 Miles Farther.
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