In Part 2 of my Eye Foods Series, I outline the key nutrients found in healthy eye foods as promoted by the American Optometric Association (AOA) and eye care professionals around the world.
Simply put, eye foods support visual function and prevent oxidation from free radicals.
They contain the following nutrients, (many of which have been isolated within the various eye structures themselves):
Beta-carotene, lutein, zeaxanthin and meso-zeaxanthin are carotenoids that block harmful blue light, support the retina and have been isolated within both the lens and retina, (specifically the macula, which corresponds to our central vision). Beta-carotene is converted to Vitamin A, which creates the vision signal, and is found primarily in the retina.
Source: carrots, sweet potatoes, orange bell peppers (cooked and raw), cantaloupe, egg yolks, avocado, zucchini (cooked and raw), winter squash
Astaxanthin is the unsung hero carotenoid that turns seafood pink. According to Dr. Jocker's, "astaxanthin is the most potent antioxidant nature has to offer". Along with anti-inflammatory and cell membrane protective benefits, it can cross both blood/brain and blood/retinal barriers. This unique, neuroprotective ability allows for a reduction in risk of both age-related eye diseases like cataracts, macular degeneration, glaucoma, as well as neurological diseases like dementia and Alzheimer's.
Source: pink seafood (ie. shrimp, crabs, wild caught salmon, fish roe), supplements
Vitamins A, C and E are antioxidant powerhouses that help protect the cells of the eye from free radicals (an unstable molecule that breaks down healthy tissues), supporting the retinal vasculature and decreasing the risk of AMD + cataracts. Vitamin C has been isolated within the cornea, lens, vitreous humor and retina, while vitamins A and E are found within the retina.
Sources: Animal liver including cod liver oil (highest source of vitamin A), eggs, nuts (ie. almonds), sunflower seeds, kiwi fruit, citrus fruits, broccoli, red bell peppers (cooked and raw), avocados, leafy green vegetables
Vitamin D is a super-nutrient wonder as it acts more like a hormone in the body helping it to regulate calcium absorption for teeth and bone health as well as boost immunity. For the eyes, however, adequate intake has been shown to reduce the risk of age-related eye diseases, like cataracts, macular degeneration and glaucoma, as well as aid in corneal tissue repair and cell communication.
Sources: oily fish, red meat, liver, egg yolks, sunlight (10-15 mins per day on bare skin is recommended) and supplemental
Anthocyanin, another powerful antioxidant, is the pigmented flavonoid that gives deep purple, blue, black and red colors to fruits and vegetables. It supports the retina, helps with night vision and in one study was found to relax the ciliary muscle in baby chicks - a potential supplement to benefit myopia progression. It's also used throughout Europe and East Asia as a common eye supplement.
Sources: blueberries, blackberries, elderberries, aronia berries, pomegranates, red grapes, currants, grape seed extract, purple carrots, purple cabbage, red onions, etc.
* The darker the berry, the more anthocyanins present.
Zinc aids in melanin production, (a protective eye pigment) and is a "helper molecule" that transports Vitamin A from your liver to your retina. It's heavily concentrated within the layers of the retina and choroid.
Sources: shellfish (oysters), grassfed beef, free range poultry, eggs, whole grains, legumes, nuts, pumpkin, hemp + flax seeds, dark chocolate, organic dairy products
Selenium acts as an antioxidant that aids in the absorption of Vitamin E
Sources: brazil nuts, organ meats, liverwurst, tuna (yellowfin), anchovies, shellfish (shrimp, oysters + mussels), eggs, spinach, garlic, mushrooms (shitake + cremini), oats, cashews, chia seeds
Omega-3 fatty acids: Docosahexaenoic acid, (DHA), Eicosapentaenoic acid, (EPA) + Alpha-linolenic acid (ALA) are crucial for the management of macular degeneration and dry eye disease. They are what make up cell membranes and found in high concentrations within the retina. DHA, particularly, has been shown in studies to be protective to the retina due to its apoptotic characteristics.
Sources: wild caught salmon, herring, mackeral, eggs, walnuts, avocados, flax seeds, flax seed oil, fish oil + cod liver oil
Omega-6 fatty acid: Gamma-linolenic acid, (GLA) is pro-inflammatory on its own, but when used in combination with EPA + DHA is a powerful anti-inflammatory used in dry eye disease.
Source: supplemental form either alone (evening primrose oil, hemp oil, borage seed oil, black currant seed oil) or in combination with Omega 3's
Lean protein and fiber help control blood sugar and cholesterol levels thereby reducing the risk of retinal vascular complications, like diabetic retinopathy.
Sources: 100% grass-fed beef, free range poultry, free range bison + lamb, game, fish, legumes, raw or cultured yogurt, whole grains (gluten-free if intolerant), organic/non-GMO soy products (tofu)
Feel free to share in the comments which nutrients you get regularly in your diet, and which ones you plan to incorporate more of to boost your eye health. (For a clear list of my top foods for your eyes, check out my previous post here.)
References
Arnarson, A. (2017, April 19). 20 Foods That are High in Vitamin A. Healthline. https://www.healthline.com/nutrition/foods-high-in-vitamin-a#TOC_TITLE_HDR_2
American Optometric Association. (n.d.) Diet and Nutrition: Adding powerful antioxidants to your diet can improve your eye health. https://www.aoa.org/healthy-eyes/caring-for-your-eyes/diet-and-nutrition?sso=y
Capogna, L. (2019). The Complete Eye Health and Nutrition Guide. Robert Rose Inc.
Jockers, D. (N.d.) 3 Major Benefits of Astaxanthin. Retrieved October 13, 2021 from https://drjockers.com/astaxanthin/
Joseph, M. (2018, November 26). Top 20 Foods High in Selenium. Retrieved October 15 from https://www.nutritionadvance.com/foods-high-in-selenium/
N.A. (2021, March 26). Selenium Fact Sheet for Health Professionals. National Institutes of Health. https://ods.od.nih.gov/factsheets/Selenium-HealthProfessional/
Nomi, Y. Iwasaki-Kurashige, K. Matsumoto, H. Therapeutic Effects of Anthocyanins for Vision and Eye Health. Molecules. 2019 Sep; 24(18): 3311. https://doi.org/10.3390/molecules24183311
Poteet, J. (2017, May 15). From Alpha to Omega: How Fatty Acids Fight Dry Eye. Review of Optometry. https://www.reviewofoptometry.com/article/from-alpha-to-omega-how-fatty-acids-fight-dry-eye
Querques, G. Forte, R. Souied, EH. Retina and Omega-3. Journal of Nutrition and Metabolism. 2011; 2011: 748361. https://doi.org/10.1155/2011/748361
Rasmussen, H.M. and Johnson, E.J. (2013). Nutrients for the Aging Eye. Clinical Interventions in Aging, 8: 741–748. https://doi.org/10.2147/CIA.S45399
Stuart, A. (N.d.) What to Know About Omega-3's and Fish. Nourish by WebMD. https://www.webmd.com/diet/features/what-to-know-about-omega-3s-and-fish#1
Your Sight Matters. (N.d.) How Vitamin D Could Protect Aging Eyes. Retrieved October 10, 2021 from https://yoursightmatters.com/vitamin-d-protect-aging-eyes/