A new, large study supports the idea that eating fish can help protect you from macular degeneration, a common vision problem as we grow older 02/16/2021
If you’ve been eating plenty of omega-3s (and that’s likely, dear Vital Choice reader, as seafood is an especially rich source) you’re doing your eyes a big favor, a large new meta-analysis shows (Zhong et al, 2021).
Your diet is especially important if you have any family history of age-related macular degeneration (AMD), which tends to creep up slowly and can lead to serious loss of vision. Your eye exam may miss the early signs (Neely et al., 2017). But it’s treatable, so be persistent and get another exam if you notice any of the symptoms described below.
Unless Americans become more diligent about preventive steps, AMD appears likely to become more common as the population ages, with groups over the age of 80 having the most serious form of the condition (National Eye Institute, retrieved 2021).
So what exactly is AMD?
Most people over the age of 60 have drusen, a small yellowish deposit of debris under the retina —a light-sensitive layer of cells at the back of the eye. The macula is the area in the center of the retina that makes images sharp.
Eye exams, as noted earlier, don’t always catch the early signs, according to a study of nearly 650 patients age 60 or older whose eyes were judged normal by an ophthalmologist or optometrist based on a dilated eye examination. In fact, when researchers used a special type of imaging known as color fundus, 25 percent actually turned out to have dry AMD. Of those, 30 percent had large drusen that would have been treatable with nutritional supplements if diagnosed (Neeley et al., 2017).
What are the symptoms?
Talk to an eye doctor, or get another exam, if the answer is “yes” to any of these questions:
- Do straight lines seem bent?
- Do you find you can’t see from the center of one or both of your eyes?
- Do you need brighter light to read than you used to?
- Do you have trouble adjusting to low light levels?
- Do printed words look blurry?
- Do colors look less bright?
- Are you having more trouble recognizing faces?
- Do you have a blurry spot? A blind spot? (Mayo Clinic, 2020).
How can you prevent AMD?
Genes are an important risk factor. Otherwise, the major risk factors are smoking and a diet low in zinc and carotenoids (Mitchell, 2018). People with obesity and heart disease are at higher risk of serious vision loss (Mayo Clinic, 2020).
It’s a great idea to eat foods rich in the essential fatty acids most plentiful in ocean fish such as salmon and tuna. The new meta-analysis included 11 studies covering more than 167,500 people with multi-year follow-ups. It found that each gram a day consumed of DHA, or docosahexaenoic acid, lowered the risk of an early form of AMD by 50 percent and each gram of EPA, or eicosatetraenoic acid, by 60 percent.
Having adequate or good blood levels of DHA and EPA was linked to a lower chance of advanced AMD as well (Zhong, 2021). These results confirmed an important study from Harvard in 2006 that compared the differences between elderly twins in which only one had AMD. Eating fish twice a week helped provide protection, and overall, eating more omega-3s lowered risk by 22 percent. (The same study found that smoking increased risk by 32 percent) (Seddon, 2006).
Along with your fish, the American Academy of Ophthalmology also recommends eating foods high in vitamin C, vitamin E, and zinc as well as carotenoids. Lutein and zeaxanthin, two key carotenoids, are abundant in retina tissue. Kale, broccoli, asparagus, and colorful fruit are good sources (Porter, 2020).
Air pollution also appears to be a factor. When you breathe in dirty air, particles travel through your body and trigger inflammation that can affect your eyes. In a new study, researchers drew on scans of the retina for more than 52,000 people aged 40 to 69 in Great Britain and found that the risk of AMD rose even from only small increases in outdoor air pollution. Similar results came in 2019 in a study of traffic-related pollution in Taiwan (Chua et al., 2021). It appears that anything that produces smoke, even wood-burning stoves, adds to your risk.
How is Dry AMD treated?
Your diet and vitamins can help slow the progression of dry AMD to a more advanced form. A tested supplement formula includes a daily dose of:
- Vitamin C (ascorbic acid) 500 mg
- Vitamin E 400 international units (IU)
- Lutein 10 mg
- Zeaxanthin 2 mg
- Zinc (as zinc oxide) 80 mg
- Copper (as cupric oxide) 2 mg (Boyd, 2021)
But your daily diet should be the true foundation of your eye-health plan. Let your vividly hued meal - how about salmon, kale salad and raspberries? - remind you of why your eyes are so precious and how healthful food keeps them strong.
Age-related macular degeneration (amd) data and statistics. (n.d.). National Eye Institute. From https://www.nei.nih.gov/learn-about-eye-health/resources-for-health-educators/eye-health-data-and-statistics/age-related-macular-degeneration-amd-data-and-statistics. Retrieved February 9, 2021.
Dry macular degeneration. Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/dry-macular-degeneration/symptoms-causes/syc-20350375 Published December 11, 2020.
Al-Zamil WM, Yassin SA. Recent developments in age-related macular degeneration: a review. Clin Interv Aging. https://pubmed.ncbi.nlm.nih.gov/28860733/ Published August 22, 2017.
Boyd K. Vitamins for AMD. American Academy of Ophthalmology. Published January 6, 2021.
Chua SYL, Warwick A, Peto T. lAssociation of ambient air pollution with age-related macular degeneration and retinal thickness in UK Biobank. British Journal of Ophthalmology. https://bjo.bmj.com/content/early/2021/01/11/bjophthalmol-2020-316218 Published online January 25, 2021.
Mitchell P, Liew G, Gopinath B, Wong TY. Age-related macular degeneration. Lancet. https://pubmed.ncbi.nlm.nih.gov/30303083/ Published September 29, 2018.
Neely D. , Bray K, Huisingh C, Clark M, McGwin G, Owsley C. Prevalence of Undiagnosed Age-Related Macular Degeneration in Primary Eye Care. JAMA Ophthalmology, https://jamanetwork.com/journals/jamaophthalmology/fullarticle/2621881 Published June, 2017.
Porter D. What Are Drusen? American Academy of Ophthamology. https://www.aao.org/eye-health/diseases/what-are-drusen Published March 25, 2020.
Porter, D. Diet and nutrition. American Academy of Ophthamology. https://www.aao.org/eye-health/tips-prevention/diet-nutrition. Published November 2, 2020).
Seddon JM, George S, Rosner B. Cigarette smoking, fish consumption, omega-3 fatty acid intake, and associations with age-related macular degeneration: the US Twin Study of Age-Related Macular Degeneration. Arch Ophthalmol. https://pubmed.ncbi.nlm.nih.gov/16832023/ Published July, 2006.
Zhong Y, Wang K, Jiang L, et al. Dietary fatty acid intake, plasma fatty acid levels, and the risk of age-related macular degeneration (AMD): a dose-response meta-analysis of prospective cohort studies [Eur J Nutr. Published online ahead of print, January 19, 2021.