If you’re like me and you’re one of the millions of people who have had their DNA tested to find out more about their risks for certain diseases or where they come from, then perhaps you’ve already heard of macular degeneration. Or maybe you already knew about it from a family member who has it.
For age-related macular degeneration, I have a slightly increased risk because I have two copies of the Y402H variant in the CFH gene. I inherited one of each from my parents. Of the marker tested, rs1061170, I have the C genotype.
Before we get into what all that means, let’s take a look at what macular degeneration is, your risk of developing it, and nutrition and supplement strategies for preventing or treating macular degeneration.
What is macular degeneration?
Macular degeneration, a disease that destroys your sharp, central vision, is the leading cause of vision loss in Americans ages 60 and older. 1 Central vision is important in everyday tasks, such as driving and reading, and even being able to see people’s faces clearly. While age-related macular degeneration (AMD) isn’t painful, it causes the death of cells in your macula, which is what allows you to see fine details.
There are two types of AMD: wet or dry. With wet AMD, abnormal blood vessels grow under the macula, often leaking blood and fluid and leading to quick damage. With dry AMD, the cells that are light-sensitive in the macula break down more slowly, causing you to lose central vision over time.
What are the early signs of macular degeneration?
With wet AMD, blurred vision is an early common symptom, while dry AMD results in straight lines appearing crooked. For some people, vision loss occurs very slowly, so you may not notice it right away. For others, loss of vision in one or both eyes may happen quickly.
Blurred vision is generally a key sign of AMD, and it worsens. Objects also may not appear as bright as they once did. However, AMD does not lead to complete blindness. 2
Macular Degeneration Risks
Your risk for macular degeneration is mainly age, with most cases starting at age 60 but some occurring earlier. Smoking also doubles your risk for AMD, 2 and it’s more common among caucasian populations than African-Americans or Latinos. A family history of AMD also makes you more susceptible to it, likely due to genetics. However, nearly 20 genes may affect your risk of developing AMD, and health professionals don’t recommend basing your risk solely on your genetics.
However, as someone who enjoys more information rather than less, knowing about my potential genetic risk was important. We’ll just focus on the two genotypes that 23andme, where I got my DNA tested, pulled for additional research as being most relevant.
Y402H variant of CFH gene & A69S variant of ARMS2 gene
Again, my genetic testing results showed I had two copies of the Y402H variant in the CFH gene and one copy of the A69S variant.
With this information, my likelihood of developing AMD is 1.64 — not quite twice the risk as the general population. My chances are a little worse than someone who has one copy of Y402H and one copy of A69S variant (1.24), but better than someone with two copies of the A69S variant (1.99). If I had my two copies of Y402H plus one copy of A69S, my likelihood ratio would shoot to 4.49. Someone with two copies of each has a 21.70 likelihood ratio!
The Y402H variant is estimated to be responsible for about 43% of AMD cases. 3
The A69S variant is estimated to be responsible for 36% of AMD cases. 4
Can you reverse macular degeneration?
Treatment of macular degeneration early (get those regular vision exams!) can help slow down vision loss, but it won’t be able to cure or reverse macular degeneration.
That said, there are ways you can work to prevent macular degeneration if you have an increased risk. Taking lifestyle factors into account, you’ll of course want to quit smoking as soon as possible if you smoke. Exercising and maintaining normal blood pressure/cholesterol levels may help ward off AMD, along with ensuring your diet is rich in leafy green vegetables, fruits, and healthy sources of fiber and protein.
Do supplements help treat or prevent macular degeneration?
Probably not, at least not on their own, and it should be pointed out up front that the dosages, especially of zinc and Vitamin E are very high in the AMD studies. We would recommend avoiding these supplement regimens altogether, or starting with a much lower dose of Vitamin E and zinc if you are inclined to try these protocols. Our view is that beta carotene supplements should be avoided altogether. To get more beta carotene, a fat soluble vitamin, try pairing carotenoid rich foods with some fat. For more see this post on how to make a salad more nutritious by adding healthy fats. Of all the supplement interventions, our view is that a combination of lutein/zeaxanthin seems to make the most sense.
However, the macular degeneration and supplements studies are out there, so with the space that follows, we report the findings.
A large body of research was performed by the National Eye Institute, called the Age-Related Eye Disease Studies (AREDS), which found a formula of certain vitamins and minerals that could help protect against AMD. 5
The two AREDS trials determined the following:
- A combination of vitamins C and E, beta-carotene, zinc, and copper can reduce the risk of late AMD by 25%.
- Adding lutein and zeaxanthin or omega-3 fatty acids (fish oil) to that mix didn’t have any overall effect, but, “replacing beta-carotene with a 5-to-1 mixture of lutein and zeaxanthin may help further reduce the risk of late AMD.” Lutein and zeaxanthin are natural antioxidants, both of which are found in the retina and lens. Interestingly, beta-carotene has been found to be associated with an increased risk of lung cancer in both current and former smokers, so this set of folks may benefit even more from the alternative combination of lutein and zeaxanthin. Participants who took the alternate combo also had an 18% lower risk of progressing to advanced AMD compared to those who were on beta-carotene.
Researchers then used the results of both studies to arrive at final recommendations of types of supplements and dosage, which have now been used for 10 years: 6
- 500 mg vitamin C
- 400 IU vitamin E
- 80 mg zinc (zinc oxide)
- 2 mg copper (cupric oxide)
- 10 mg lutein and 2 mg zeaxanthin
Two-thirds of study participants also took a daily multivitamin while on this supplement regimen. Note that omega-3 supplements weren’t necessarily recommended by researchers based off study results, but they still suggest a diet high in fruits and vegetables (leafy greens) in addition to eating fish regularly — the Mediterranean diet is a good example. 7 The DHA in omega-3 fatty acids is particularly important in maintaining the integrity of retinal cells, so it may not be a bad idea to supplement with fish oil or a vegan omega-3 supplement if you do not regularly eat fish.
While there is no known treatment for preventing AMD, supplementing with with these six vitamins and minerals may be more beneficial in slowing the progression of the disease for those with intermediate or advanced AMD than diet or lifestyle changes alone. But for those concerned with developing AMD, having a diet high in lutein/zeaxanthin may decrease your risk.
While I only have a slightly increased risk of developing macular degeneration, I think it’s important for me to add more leafy greens to my diet and possibly begin supplementing with lutein/zeaxanthin. Though I love my fruits and vegetables, leafy greens are one of those items at the grocery store I tend to gloss over (aside from simple spinach), so it’s time to begin prioritizing some more recipes with Swiss chard, kale, and mustard greens. And while researchers have not found an exact formula for preventing AMD, supplementing with zinc and copper may be an option for some if they don’t get enough of it in their diets.