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Antioxidant Supplements for Macular Degeneration

Age-related macular degeneration (AMD) is one of the major causes of visual impairment in the elderly: it affects central vision, impairing the ability to read and recognize faces while preserving some peripheral vision. It comes in two forms: wet and dry. Dry macular degeneration is by far more common, but wet macular degeneration, involving the proliferation of blood vessels, is more severe. 

There is evidence that antioxidant vitamin supplementation may slow the progression of the dry type when it is already established and moderately severe, but the published evidence does not support the use of these supplements for prevention or for patients with early stages of the disease. Some people are using it for prevention, but there is concern that the risks might exceed any benefit. Of more concern, it appears that a manufacturer’s (Bausch & Lomb’s) advertising has gone way beyond the available evidence. 

This review by the American Academy of Ophthalmology covers the subject well. 

A Cochrane review  found that the evidence for effectiveness of antioxidant vitamin supplements comes mainly from one large trial, the AREDS trial, that was funded by the manufacturer Bausch & Lomb. The AREDS study used vitamin C, 500 mg; vitamin E, 400 IU; beta-carotene, 15 mg (approximately 25,000 IU vitamin A); zinc 80 mg as zinc oxide; and copper, 2 mg, as cupric oxide. (The copper was added to prevent copper-deficiency anemia, an adverse effect of high-dose zinc.)  

The effect was statistically significant but modest. Patients taking the antioxidant and zinc supplement had a 23% chance of developing vision loss from advanced AMD compared to a 29% chance of developing vision loss from advanced AMD for patients taking a placebo pill.

The Cochrane review concluded

The generalisability of these findings to other populations with different nutritional status is not known. Further large, well-conducted randomised controlled trials in other populations are required. Long-term harm from supplementation cannot be ruled out. Beta-carotene has been found to increase the risk of lung cancer in smokers; vitamin E has been associated with an increased risk of heart failure in people with vascular disease or diabetes.

Bausch & Lomb has been selling a product called PreserVision Eye Vitamin AREDS Formula. It contains the same combination of vitamins C, E, beta carotene and zinc that was shown to slow the progression of moderate to advanced macular degeneration in the AREDS trial.  The authors of that trial recommended this treatment for patients with extensive intermediate size drusen (deposits seen on ophthalmoscopy that are characteristic of AMD), at least one large druse, noncentral geographic atrophy in one or both eyes, or advanced AMD or vision loss due to AMD in one eye, and without contraindications such as smoking.

Bausch & Lomb has tried to improve their formula to reduce the risk associated with beta carotene. Their PreserVision Eye Vitamin AREDS 2 Formula omits the beta carotene and adds lutein and zeaxanthin, as well as omega-3 fatty acids. Is the new formula better? We don’t know, because the results of the AREDS 2 trial to test it will not be available until 2013. The product has already been recalled  for reformulation after some patients reported difficulty swallowing the soft gels or experiencing a choking sensation. The recall affects only the US: the product is still available in Europe and other parts of the world, and we can expect to see it back on our shelves as soon as it is put into an easier-to-swallow form.

Bausch & Lomb has been advertising their AREDS 2 Formula as “the latest scientific advancement in eye vitamin therapy” and has urged ophthalmologists to give it to their patients. A recent article in The Medical Letter criticized them, saying “That seems premature at best.” Much harsher words could be used.

Bausch & Lomb also sells other products (Ocuvite, Ocuvite Lutein, etc.) that contain lower amounts of the vitamins and minerals used in the AREDS trial, sometimes with other ingredients added, like lutein and omega-3. The rationale for products with these dosages is hard to fathom.

Is this Big Pharma or Big Supplement? The products carry the FDA warning “not intended to diagnose, treat, cure or prevent any disease,” yet they are clearly being marketed to treat a disease.

Should everyone with moderately severe AMD be taking antioxidant supplements?  I’m not sure. Since there is little else to try, if I had advanced AMD I might be tempted. But I think caution is warranted due to the following red flags: 

  • Evidence boils down to one study funded by manufacturer.
  • Not replicated.
  • Concerns about harmful side effects; no long-term safety data.
  • Modest effect.
  • No clear rationale for the particular combination and dosage of ingredients.
  • Hype by the manufacturer.

 

 

Posted in: Herbs & Supplements, Ophthalmology

Leave a Comment (7) ↓

7 thoughts on “Antioxidant Supplements for Macular Degeneration

  1. stewiegriffin81 says:

    Hi Harriet,

    I thought you might be interested in this:

    Christen, et al (2010). “Vitamin E and Age-Related Macular Degeneration in a Randomized Trial of Women”. Ophthalmology. 117, 6. 1163-1168.

    It is a very large RCT (39,000 women) with a long follow up (10 years) showing that vitamin E has no effect on preventing the development of age-related macular degeneration.

    Yet more evidence that antioxidants do very little indeed.

    Cheers

  2. Scott says:

    I’ve always found antioxidants one of the more interesting nutritional questions. There’s ample evidence that foods rich in antioxidants tend to be good for you – but that mostly just corresponds to the long-established fact that a healthy diet should include ample fruits and vegetables. And the evidence for antioxidant supplementation is lacking at best.

    Yet, all SORTS of foods and supplements are advertised acting like antioxidants are the Philosopher’s Stone.

  3. Wholly Father says:

    Just wanted to clarify a key point. Dr. Hall characterizes the AREDS as a study funded by Bausch and Lomb. This is a bit of a simplification.

    AREDS was placebo controlled, multicenter, randomized clinical trial designed and executed by the National Eye Institute of the National Institutes of Health. Bausch and Lomb provided the supplements used in the study, and may have also provided some material support (I’m not sure to what extent), but this was first and foremost an NIH study.

  4. Danio says:

    There’s a similar debate about supplementation in the Retinitis Pigmentosa research community. Vitamin supplementation in particular seems to be low hanging fruit for the ‘what’s the harm?’ contingent.

    (My SBM-inspired take on the RP story can be found here)

  5. biguglyjim says:

    Please, for starters know that I am NOT a supplement supporter and I do believe very deeply in science-based medicine and the idea of proper testing and all that is good with a reasoned, rational approach to healing. However, my mother (a trial of one) does not.

    My mother was diagnosed with macular degeneration. She is a woo peddler most extraordinary for the Manatech line, as well as a product demonstrator at her local wing nut natural health food store. When she was diagnosed, she felt “very confident” that taking a ludicrous amount of one of the Manatech products would fix her. So she proceeded to take way too much of the stuff, and when next she presented herself for a checkup, there was “no evidence of macular degeneration”.

    Now, this is testimonial and it’s based on the accuracy of someone who may well not be entirely accurate. However, I was intrigued and looked into the product, which is essentially made up of veggies. In looking into things, anti-oxidants were often recommended to slow the progression of the disease, but the idea that they would undo it still seems ENTIRELY far fetched to me. Of course, my woo-mother cannot possibly conceive of any other reason why the issue has gone away.

    Naturally, my first thought is to question whether or not there was actual macular degeneration in the first place. But what I can say for certain is my mother is certain that anti-oxidants saved her vision, and while I can’t prove or disprove it (nor is one person a legitimate trial), it probably bears some further evaluation, even if it is just to determine that my ma has the power of placebos working for her).

  6. biguglyjim says:

    Also, it should be noted that she may well have overdosed on a variety of very damaging chemicals in the process of doing this because of her lack of understanding of health. I wrote about it on my blog if anyone’s curious.

  7. Jeff says:

    The AREDS study has provided evidence for omega-3s as a preventive measure against AMD:
    http://www.ncbi.nlm.nih.gov/pubmed/19812176

    Then there’s this 2009 study from the U.K.:
    http://www.sciencedaily.com/releases/2009/06/090619082129.htm

    “The latest study showed that intake of high levels of both carotenoids preserved the macular pigments, slowing down the progression from early AMD to late AMD. In contrast, the macular pigments of participants in a placebo group declined steadily.”

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