Good morning! I’m Dr. David Richardson, a cataract and glaucoma surgeon in Southern California. And right now I’m discussing a series of videos on the holistic approach to treating glaucoma. So, looking at things other than just intraocular pressure, also known as IOP…

Today I’d like to talk about diet and nutrition and some of the research that’s available on that.

Alright let’s get going.

So, it will come as no surprise to those who have watched the first few of my videos that I’m going to state that anything that’s good for your cardiovascular health is also good for your optic nerve and potentially for either preventing or helping to treat glaucoma. So what’s the available research that suggests that that’s the case and not just my opinion.

Fruits and Vegetables

Most of the research that’s available is, unfortunately, just observational research. Now, what that means is that there’s a group of people that were followed, often these are nurses in many of the studies, and associations are made. So pretty much everything they do is looked at from diet, exercise, and then correlations are discovered. So one of the larger studies that looked at diet and the development of glaucoma… or this is one of the things that’s looked at. Generally these studies have multiple reports that come from them, each one breaking down a certain association with a particular disease, but in this particular study that looked at diet in black women… in this study and the association with development of glaucoma, there was a protective benefit associated with vegetables and fruits.

Oranges and Peaches

Now the study broke that down a bit. What the overall suggestion was that those who had at least three servings vegetables and fruits had a decreased risk of developing glaucoma but of course you’d like to know which fruits and which vegetables. And so they did break that down a bit those who had at least three servings of oranges or peaches had a decreased risk of developing glaucoma. Now whether or not orange juice or canned fruits provide the same benefit is not as certain. And there was some suggestion in the study that it had to be the whole fresh fruit.

Kale and collard greens

What else? Kale. Kale and collard greens—I mentioned that in an earlier video for the lutein zeaxanthin content but kale and collard greens also provided a benefit. Now interestingly you only needed two servings of kale or collard greens a week in order to have the protective benefit.

Green Leafy Vegetables (High in Nitrates)

Now there are other vegetables that are worth considering in terms of trying to prevent glaucoma. So in general the green leafy vegetables, which once again are also just good for general retinal health seem to provide some benefits and protection for glaucoma with the optic nerve. In particular, those vegetables that are high in order called nitrates, not to be confused with nitrites which you find in salami and processed meats, deli meats things like that. The nitrates are actually converted by the body into nitric oxide. Now nitric oxide has a beneficial effect on blood flow perfusion to the optic nerve. and indeed there’s a recently FDA-approved medication: Vyzulta, which is a combination of a prostaglandin analog which tends to be a very effective class of intraocular pressure lowering medications plus a nitric oxide releaser. So essentially, it’s prostagladin analog plus a source of nitric oxide and that both provides an additional intraocular pressure lowering effect if it may actually also have a neuroprotective effect and in that it may improve the blood supply to the optic nerve.

Anthocyanin

Black Currants

So what else? There are a class of molecules called anthocyanin that are found in black currants. And black currants have been shown in at least one study to stabilize visual fields and since in the treatment of glaucoma what we are trying to do is maintain good vision, anything that can stabilize visual fields is worth considering.

Eggplants

Then another source of the Anthocyanins is eggplant. It turns out that as little as 10 grams per day. I don’t know how many servings that is, can provide some benefit. Eggplant is also a good source of Vitamin C. you do, of note is, is that you do need the purple skin of the eggplant so it’s not just the meat the skin is important in order to get this benefit.

Omega-3 Fatty Acids

Omega-3 fatty acids, which I generally recommend for my patients with a type of dry eye (they don’t help all types of dry eye but dry associated with my bohmian gland dysfunction can benefit from omega-3 fatty acids. And the Omega 3 fatty acids seem to provide some benefit in terms of blood flow to the optic nerve.

Now, there may also be some pressure lowering benefit and in order to get a source of omega-3 fatty acids in the diet you really need to eat fatty fish at least 3 times a week so what types of fish are fatty fish? Wild-caught salmon, sardines, mackerel, tuna… Did I say Herring? So, not something that usually comes to mind (not to me anyway). So if you’re not getting a fatty fish in your diet at least three times a week then you really should consider supplementing with a high-quality omega-3 fatty acid. Generally I just recommend you stay away from the store brands. There are some high quality brand names such as Nordic Naturals. There are supplements that are formulated specifically for eye diseases. And those are available as either an eye doctor’s office or online.

Flavonoids (such as Cocoa and Tea)

Let’s see, what else…Oh! Interestingly enough, there is another chemical, the flavonoids. Flavonoids are naturally occurring antioxidants and these are found in such things as cocoa—so, in chocolate and tea. Now, if you’re thinking about chocolate, I recommend that you stick to dark chocolate, so you limit the number of carbohydrates because what you don’t want to do (of course) is, take something to improve your glaucoma, but end up making your blood sugar higher or cardiovascular issues worse. So dark chocolate and a very small amount: one or two squares a day, not one or two bars. One or two squares.

Other things that are relatively high in flavonoids: Tea. Now green tea gets all the credit but black tea also has a high flavonoid content and benefit there. And the interesting thing about flavonoids is that they may actually help protect the optic nerve and decrease the progression of visual field loss. So if you’re not already a tea drinker, there are all kinds of great flavor and tasting teas out there. I highly recommend that you have 1 to 2 cups of tea a day. It’s actually probably reasonable for most of us to cut down on our coffee and swap over to tea which has lower caffeine content.

Goji Berry

And the last thing that I’m going to mention here is something that you’re probably not getting in your diet but is really exciting (at least in animal studies). There’s no human studies that I’m aware of yet that look at this protective benefit (at least not high quality study). But the Goji Berry extract was fed to rats and these rats were essentially modified so that their pressures went up really high. And the Goji berry extract protected the retinal ganglion cells—those are the cells that are actually damaged in glaucoma, protected them from the damage that would normally occur with elevated intraocular pressure. So that’s really an exciting, early laboratory research but it needs to be replicated in humans. Of course, without actually actively increasing the pressure in humans…that would not be an ethical study.

So anyway, this has been a long video but I know it’s a video that has information that’s of interest to many of those who have followed my written work online so I felt like it was worth the extra time and detail today.

Anyway, I hope you agree and I look forward to my next commute with you. All right… Take care.

 References

^[1] Giaconi JA, Yu F, Stone KL, et al. The association of consumption of fruits/vegetables with decreased risk of glaucoma among older African-American women in the study of osteoporotic fractures. Am J Ophthalmol. 2012;154(4):635-44.

^[2] Ibid.

^[3] Ibid.

^[4] Kang JH, Willett WC, Rosner BA, Buys E, Wiggs JL, Pasquale LR. Association of Dietary Nitrate Intake With Primary Open-Angle Glaucoma A Prospective Analysis From the Nurses’ Health Study and Health Professionals Follow-up Study. JAMA Ophthalmol. 2016;134(3):294–303. doi:10.1001/jamaophthalmol.2015.5601

^[5] Yoshida K, Ohguro I, Ohguro H. Black currant anthocyanins normalized abnormal levels of serum concentrations of endothelin-1 in patients with glaucoma. J Ocul Pharmacol Ther. 2013 Jun;29(5):480-7. doi: 10.1089/jop.2012.0198. Epub 2012 Dec 21.

^[6] Igwe SA, Akunyili DN, Ogbogu C. Effects of Solanum melongena (garden egg) on some visual functions of visually active Igbos of Nigeria. J Ethnopharmacol. 2003 Jun;86(2-3):135-8.

^[7] Ren H, Magulike N, Ghebremeskel K, Crawford M. Primary open-angle glaucoma patients have reduced levels of blood docosahexaenoic and eicosapentaenoic acids. Prostaglandins Leukot Essent Fatty Acids. 2006 Mar;74(3):157-63. Epub 2006 Jan 10.

^[8] Patel S, Mathan JJ, Vaghefi E, Braakhuis AJ. The effect of flavonoids on visual function in patients with glaucoma or ocular hypertension: a systematic review and meta-analysis. Graefes Arch Clin Exp Ophthalmol. 2015 Nov;253(11):1841-50. doi: 10.1007/s00417-015-3168-y. Epub 2015 Sep 4.

^[9] Chan HC, Chang RC, Koon-Ching Ip A, et. al. Neuroprotective effects of Lycium barbarum Lynn on protecting retinal ganglion cells in an ocular hypertension model of glaucoma. Exp Neurol. 2007 Jan;203(1):269-73. Epub 2006 Oct 11.

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