by Mia Syn, M.S., R.D.
Many of us know that adding carrots into the diet, is good for our eyes. What we may not realize is that there is a plethora of food and nutrients that can help keep vision sharp and slow the natural decline that occurs with age. Some of these nutrients include antioxidants lutein, zeaxanthin and vitamin E, as well as omega-3 fatty acids. Knowing how these nutrients work within the eye and where to seek to them, is one way to help keep eyes looking and feeling healthy.
Nutrition and Your Eyes
The National Eye Institute encourages a healthy diet as being a key factor to eye health. (1) Age-related visual decline is inevitable for most individuals and the risk of developing eye diseases increases with age. (1)
There are several types of eye disorders. Two common types include cataracts, characterized by clouded vision, and diabetic retinopathy, a visual impairment brought on by high blood sugar damaging blood vessels in the retina. Additional conditions include dry eye disease marked by insufficient tear fluid and glaucoma characterized by degeneration of the optic nerve leading to poor vision or blindness. The leading cause of blindness in the developed world is age-related macular degeneration (AMD), which is caused by degradation of the central part of the retina called the macula, which controls visual acuity. (2) While genetics and age play a role in the development and progression of these diseases, diet and lifestyle also contribute, thus empowering us to make good choices.
Zeaxanthin and Lutein
Zeaxanthin and lutein – they aren’t only tongue twisters, but two carotenoid antioxidants thought to play a significant role in supporting eye health since they are found concentrated in the macula.
Since the lens and retina suffer oxidative damage, these antioxidants are considered protective by sequestering free radicals, which in turn help to protect and repair cells. Too many free radicals can contribute to eye diseases including AMD. (3) The National Eye Institute recommends a diet high in antioxidant-containing foods for those susceptible to age-related disease. (1)
The good news is that these two powerful antioxidants are usually found together in foods. Vegetables and eggs are considered the best sources. (4) Vegetable sources include dark-colored leafy greens, carrots, corn and orange peppers. (5) Carotenoids are best absorbed when eaten with a healthy fat source like olive oil or avocado. (5)
Vitamin E is another power antioxidant and fat-soluble vitamin thought to play a role in supporting eye health. Several observational studies have suggested a relationship between high vitamin E levels and lens clarity as well as reduced risk of cataract formation. (5) Cataracts are characterized by accumulation of proteins damaged by free radicals. (5) Since vitamin E is an antioxidant, it helps reduce free radicals and mitigate their damage. Reliable sources of vitamin E include nuts and oils as well as carrots, squash and peaches. Non-fat containing sources of vitamin E should be consumed with healthy fat for optimal absorption.
Omega-3 Fatty Acids
Omega-3 fatty acids are important for proper retinal function. (6) Omega-3 fats exist in three forms: eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and alpha-linolenic acid (ALA). The DHA and EPA forms found in cold-water fish like salmon, tuna and halibut are the most important for vision. (7) ALA is largely found in plant foods like walnuts and flax, but requires conversion to DHA in the body in order to be active. Since this conversion is largely inefficient in individuals, it is best focus on consuming sources of EPA and DHA. If you seek out supplements, it is important to preserve the quality of omega-3 fats by storing them in the refrigerator to prevent oxidation.
Having a high body mass index (BMI) can put you at greater risk of developing diabetes, which can have a negative impact on eye health. Elevated blood sugars are directly linked to blindness and neuropathy. (1) Thankfully diets rich in foods containing these nutrients will naturally promote a healthy body weight.
3.Fletcher AE:Free radicals, antioxidants and eye diseases: evidence from epidemiological studies on cataract and age-related macular degeneration. Ophthalmic Res. 2010;44(3):191-8. https://www.ncbi.nlm.nih.gov/pubmed/20829643
4.Abdel-Aal, EM., Akhtar H., Zaheer K., et. al: Dietary Sources of Lutein and Zeanthin Carotenoids and Their Role in Eye Health. Nutrients. 2013;5(4):11691-1185. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3705341/
5. Rizvi S., Raza ST., Ahmed F., et. al: The Role of Vitamin E in Human Health and Some Diseases. Sultan Qaboos Univ Med J. 2014;14(2):e157-e165. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3997530/
6.Querques G. Forte R. Souied EH.: Retina and Omega-3. Journal of Nutrition and Metabolism 2011;(2011):748361. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3206354/
7. Swanson D, Block R. Mousa, SA: Omega-3 Fatty Acids EPA and DHA: Health Benefits Throughout Life. Advances in Nutrition. 2012;3:1-7. http://advances.nutrition.org/content/3/1/1.full