Currant Treatment for Glaucoma

If You Have Glaucoma, Eat More of These

In my video, Dietary Prevention for Age-Related Macular Degeneration, I discussed how eating goji berries with nuts and seeds can help build up yellow plant pigments such as lutein and zeaxanthin in our eyes to help fight age-related macular degeneration.

But once we’ve preserved the pigment in our retinal pigment epithelial cells, we need to keep them alive. This may be where anthocyanin phytonutrients come in. Anthocyanins (from the Greek anthos, meaning flower, and kyanos, meaning blue) are natural plant pigments that make pansies look purple and turn 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 keeps blueberries blue and blackberries black.

As we age, our critical retinal pigment epithelium (RPE) layer starts to break down. However, we may be able to decelerate that aging with blueberries. In the study I profile in my video, Dietary Treatment of Glaucoma, human RPE cells bathed in blueberry anthocyanins had fewer free radicals and a lower proportion of aged cells, suggesting that blueberries and other red, blue, and purple pigmented fruits and vegetables may help prevent age-related macular degeneration. Blueberries may be especially important for blue eyes, as can be seen in my video Greens vs. Glaucoma.

Preventing disease 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 glaucoma with black currants. They gave people black currants for six months and found that black currants significantly boosted the blood flow to their optic nerve. The results suggest that black currants might be a safe and valuable option, but because the study was not double-blind and there was no control group, I didn’t report on it when it was initially published. But now we’ve got just such a study. Glaucoma patients were split into two groups—half got black currants; the other half didn’t.

The study measured the deterioration of the patients’ visual fields in both groups in the two years leading up to the study. Despite taking the best glaucoma drugs on the market, the subjects’ visual fields deteriorated. Then the study starts. The berry-free control group continued to worsen, but the berries appeared to stop the disease in its tracks after both one and two years. And since there’s no downside to berries (only good side-effects), in my professional opinion everyone with glaucoma should be eating berries every day.

For more on the latest science on preventing and treating vision loss, check out Greens vs. Glaucoma, where I detailed the best foods to help prevent glaucoma. My previous treatment of glaucoma can be found here: Prevent Glaucoma and See 27 Miles Farther.

I’ve mentioned anthocyanins before in:

They may be why purple potatoes (Anti-Inflammatory Effects of Purple Potatoes) and purple cabbage (Superfood Bargains) 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.

More on currants in Enhanced Athletic Recovery Without Undermining Adaptation.

-Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my videos for free by clicking here and watch my full 2012 – 2015 presentations Uprooting the Leading Causes of Death, More than an Apple a Day, From Table to Able, and Food as Medicine.

Image Credit: Rachel / Flickr

  • segnitia

    Do people with beeturia excrete all those beneficial anthocyanin?

    • I have beeturia but never excrete any pretty colors when I consume black currant.

  • Noeb49

    Dr. Gregor, are these fresh or dried black currants used in the study? Not sure I’ve ever seen them at my grocer.

  • Nikki

    would black current oil have any benefits?

  • Guest

    Watch out for the nightshades plants, and those containing solanine. Arthritis cause.

    goji berries, tomatoes, peppers, eggplant, tobacco, and more.

    Some arthritis and pain issues derived from other ailments react negatively to

    HUMAN CONSUMPTION. All plants, fruits, have defense mechanism.

    • Guest

      And potatoes, one of the strongest nightshades to avoid if one has inflammation, arthritis,
      or other pain issues.

      • What is the scientific evidence to support these wild-sounding assertions?

    • Veganrunner

      Have you ever seen any articles published on this? I have done Medline searches and haven’t found anything.

    • Most people don’t have to a problem with solanine. Don’t flame the nightshade concern. I personally consume lots of nightshades without a problem. If you feel you have a problem with nightshades, go get tested for the allergy.

    • HereHere

      I remember the American Academy of Dietetics published their review of nightshade plants and found that they were not harmful. Same thing with the blood type diet, it was not credible. They were positive about vegetarian and vegan diets, with some cautions (like ensuring people get adequate calcium, iron and zinc). They are now called the Academy of Nutrition and Dietetics.

  • backoh

    You write primarily about dark berries, primarily black currants but then in the last sentence you say everyone with glaucoma should be eating berries every day. Are lighter berries also beneficial for glaucoma? I’ve been trying to sample different varieties of black currants when I get the chance and I haven’t found a variety that I really like yet. I prefer red currants and other dark berries like blueberries and marionberries. Can you advise on specific varieties so I know which to grow?

    • Suzanne

      The berries used in the study are known as Cassis and are not the currants grown in the US, according to other videos on this website. St. Dalfour is a French company that manufactures preserves and has a Cassis preserve that I use as a spread. In Japan, we have a Cassis extract (supplement) containing the anthocyanins. It is expensive, but I am willing to use it as a treatment. Nutritional support is popular here due to numerous commercial applications regularly researched by Japanese scientists (as these two cited studies attest). I also use drops for Glaucoma, however, I am optimistic that the addition of these berries can help maximize visual acuity.

  • Loving it, want more

    Fresh and frozen only! Or dried ok? And are other berries as helpful, or is it something special in currants? THNK YOU Dr G, you ROCK!

    • Loving it, want more

      OK I see now there is a special DR3 variety of anthocyanins in currNts, given they took them in tablet form, I assume dried currants are ok. Or buy tablets…

  • Dommy

    The principle is simple: the darker the berry the more beneficial pigment it contains.

  • Loving it, want more

    OK I see now there is a special DR3 variety of anthocyanins in currNts, Nd given they took them in tablet form, I assume dried currants are ok. Or buy tablets…

    • Dommy

      Almost always, the whole food is more healthful than a tablet.

    • Alice

      The small dried fruits sold as “currants” are actually dried very small grapes–Zante currents, used for baking. The black currant used here is a genus Ribes species, related to blueberries, not grapes. It’s really dark and tiny. I was surprised to see a study using them since I’ve never seen them commercialy available. In the UK they’re a traditional source of vitamin C for children–a sweet fruit concentrate called “Ribena” They’re very strong flavored and most people need to cultivate a taste for them.

      • KT
        • Alice

          Yup. Those are black currants. That’s a nice website. I’m amazed at the acreage

          of currant bushes in the photo. I have a mere 3 bushes and they take days to pick–very very labor intensive picking. Their fruit price is a bargain!

          • HereHere

            I’m thinking for those who live in apartments, they may be able to find black currents in polish/russian specialty food stores or in jams or jellies. Not exactly the healthiest option, though. If I recall, the fresh berries are extremely tart. Best for juicing with added source of sweetener (fresh apple juice that you make yourself, for example or from a trusted brand (Knudsen?)).

      • HereHere

        Ribena got into legal troubles because of their Vitamin C claims. They were fined.

        The stuff they sell on my supermarket shelves has additives, so I wouldn’t call it a fresh product or a whole food.

  • Roy Salley

    o fresh red or black grapes give the same protection as currents?

    • peseta11

      Roy, almost certainly not; as another post says, the currants being discussed are not related to grapes or Zante ‘currants’ which are raisins. The genus Ribes (red or black currants) is the sole member of a family (Grossulariaceae) closest to the Saxifrage family, not as elsewhere stated bluberries (which are Heath family members).
      So unless the resveratrol in grapes does something similar, grapes (in its own family) won’t help.

  • Jen

    Dr. Greger why don’t you include in your articles how much was given of any foods you tell about?
    And how did they get people to eat the black currants when they are not very tasty?
    Details are just as important as research results when it come to using a food for a health problem. Thank you.

  • Guest

    This study dealt with normal tension glaucoma only. My assumption is is that those of us with glaucoma who have ocular hypertension as the cause would therefore not benefit from the methods this study used. Or at least that would hold true until further research confirms that ocular hypertension glaucoma is also improved with the study’s treatment methods.

  • ThomasN

    I’ve never seen fresh black currants in any store in the US. When I can’t find a fresh produce, my second choice is freeze-dried powder, but I can’t find freeze-dried black currant powder at Amazon or any other health-food online store I shop at. I did find the French black currant jam another reader had mentioned, but it’s sweetened with fruit juice, which is like sweetening with sugar water, so I’d like to avoid it. Any ideas about consuming black currant regularly is appreciated. Thanks

    • Thea

      ThomasN: I know someone who gets frozen black currents (at least I think it is the right kind that we are talking about here) on-line. The shipping is very expensive since they ship with dried ice to keep it frozen. But it might be worth getting???? Do you want me to try to find the supplier?

    • laguna has freeze dried for 30 per lb.
      Also has excellent products, i have ordered many and am always happy

  • ThomasN

    Here’s a paper that lists the anthocyanin content of some common foods: J. Agric. Food Chem. 2006, 54, 4069−4075 (available online free of charge; I tried to upload it without success.)

    • peseta11

      Thanks, ThomasN; I see from that Wu et al paper that black currants are highest in delphinidin and cyanidin. So my reply to Roy should be modified– though red grapes won’t help, Concord grapes have similar though much lower anthocyanin content.

  • AliceJ

    I have been conscientiously eating roughly two tablespoons of black currants daily — a bit of overkill from Darryll’s calculations of 1 1/3 tablespoons of black currants daily — to get the adequate amount of anthocyanin to protect against the deleterious effects of glaucoma. If I were to switch to blue berries, could I give up the black currants? Shipping costs to the West Coast for the black currants are astronomical. Or could I lessen my costs by eating some blue berries and fewer black currants? If I could switch to blue berries — either totally or partially, what quantity a day would I need to consume? Thank you for your valuable input.