Reducing the Risk of Vision Loss from Macular Degeneration
(A review of recent recommendations and nutritional studies - D. Alan Chandler, MD)
Age-related macular degeneration (AMD) is the leading cause of permanent visual loss in the United States especially in people aged 65 years and older. AMD affects the central vision, which is used for daily tasks such as reading, driving, and watching TV. According to the Centers for Disease Control (1), the number of Americans aged 40 and older with vision loss from AMD is estimated to reach 2.95 million in 2020, with 2-3 times that many (over 7 million people) being at significant risk. In spite of significant advances in treatment of primarily the "wet" type of AMD, prevention is a major emphasis because there is a much lower risk of vision loss with "dry" or no AMD than with wet AMD. Fortunately, there are many modifiable risk factors.
Tobacco use has been one of the leading risk factors for AMD, and fortunately the rate of tobacco use in the United States has been declining for decades. Reaching a peak in the early 1960's with over 60% of adult Caucasian males smoking, the rate in 2015 dropped to 15.1% of U.S. adults (16.7% of men and 13.6% of women). 80% of current U.S. smokers (36 million) smoke daily. Without question, the best thing that an individual can do to reduce the risk of visual loss from AMD is to stop smoking.
Getting Regular Eye Exams and Following the Doctor’s Recommendations
According to the American Academy of Ophthalmology, it is important for adults to have a baseline eye examination by age 40 (sooner if there is a family history of diabetes, hypertension, or a family history of eye disease). For adults aged 65 and older, it is recommended to have a complete eye examination every 1-2 years. This is regardless of family history, health, gender or race/ethnicity.
Based on the results of the eye examination, it might be recommended for a patient to take a vitamin supplement to reduce the risk of vision loss from AMD. In patients determined to have intermediate or high risk based on findings during the exam, an "AREDS" vitamin is usually recommended (Age-related Eye Disease Study) and taking this vitamin has found to reduce the risk of vision loss from AMD by 25%. There are a number of these available over the counter, with Preservision AREDS2 being the most commonly recommended. It is important for the vitamin used to be labeled "AREDS 2" not just an "eye vitamin". It is also important to follow the dosing, as most are twice a day rather than once a day. The AREDS 2 vitamin is not a complete multivitamin, and is composed of the antioxidants zinc, vitamin C, vitamin E, lutein, zeaxanthin, and copper in very specific amounts. Many patients take a multivitamin such as Centrum Silver in addition to the AREDS 2 vitamin.
If a person is found to be at risk for AMD, it is recommended to self-monitor the vision of each eye periodically using an Amsler Grid or similar tool. The wet form of AMD needs to be treated rapidly if it develops. This may often appear as an area of distortion at or near the center of the vision, a loss of the central vision, or a blind / blurry spot near the center of the vision. If often appears suddenly and is painless. If any symptoms such as these arise, contact an eye doctor immediately. There are other eye conditions that can cause similar symptoms, but wet AMD is one that requires immediate treatment. (2)
Dietary / Nutritional Recommendations
The nutritional benefits of reducing the risk of AMD by eating certain foods is becoming more and more noteworthy. A February 2019 study (3) published in the American Journal of Ophthalmology found that a diet including 200 grams of vegetables per day, 2 fruits per day, and 2 servings per week of fish (particularly fatty fish such as salmon and tuna) were associated with a significantly reduced risk of AMD. In the study, which looked at 4202 participants from the Rotterdam Study age 55 and older, only 31% ate the recommended amount of vegetables per day, 55% ate the recommended 2 fruit2 per day, and only 12.5% ate 2 servings per week of fish. Only 3.7% ate the recommended amounts of all 3 groups. However, those that followed the daily recommendation for all 3 groups had a risk reduction of AMD of 42%. Following the recommendation of eating 2 servings a week of fish alone accounted for a risk reduction of 24%. (Note that 200 grams of vegetables per day equals 1.5 cups or 7 oz. of vegetables).
The nutrients lutein and zeaxanthin have been especially associated with a reduced risk of AMD, and these are found in leafy green vegetables such as kale, endive, spinach, turnip greens and collard greens, and in orange/yellow bell peppers, broccoli, zucchini, squash, and yellow corn. Fruits with especially large amounts of lutein and zeaxanthin include blackberries, raspberries, kiwi, grapes and persimmons. Fatty fish containing omega-3 fatty acids are especially associated with protection from AMD, including salmon, tuna, mackerel, and sardines.
The patient data from this Rotterdam study were combined with data from 614 patients aged 73 or older from the French Alienor study to determine the benefits of adhering to the Mediterranean diet in reducing the risk of AMD (4). High adherence to the Mediterranean Diet was associated with a 41% reduced risk of advanced AMD including atrophic AMD. The Mediterranean Diet (5) is characterized by abundant plant foods (fruit, vegetables, breads, other forms of cereals, potatoes, beans, nuts, and seeds), fresh fruit as the typical daily dessert, olive oil as the principal source of fat, dairy products (principally cheese and yogurt), and fish and poultry consumed in low to moderate amounts, zero to four eggs consumed weekly, red meat consumed in low amounts, and wine consumed in low to moderate amounts, normally with meals.
Another study published in the American Journal of Clinical Nutrition in 2008 (6) found that consuming at least one serving per week of oily fish such as salmon, tuna, mackerel, and sardines reduced the risk of wet AMD by 50% compared to those eating less than one serving per week. Generally, the fish should be broiled or grilled rather than fried. (Importantly, the use of omega 3 supplements was NOT found to reduce the risk of vision loss in AMD, while eating the actual fish itself was).
Other notable nutritional issues associated with AMD highlight foods to avoid. Eating a diet high in saturated fat (found in foods such as meat, butter, and cheese) and being overweight are associated with an increased risk of AMD. Heart disease and elevated cholesterol levels are also risk factors for AMD.
Protection from Ultraviolet Light
Wearing ultraviolet protecting sunglasses labeled UV400 is recommended by the American Macular Degeneration Foundation.
Main Takeaway Points:
- Stop Smoking
- Get Regular Eye Examinations and take AREDS 2 vitamins if indicated
- Contact you eye doctor immediately with any change in vision
- Eat oily fish such as salmon, tuna, mackerel, or sardines twice a week, preferably broiled or grilled rather than fried
- Eat 1.5 cups a day of leafy green vegetables such as spinach, endive, kale, collard greens, turnip greens or yellow/orange bell peppers. Other good options include broccoli, yellow corn, zucchini and squash.
- Eat 2 servings of fruit per day, especially blackberries, raspberries, kiwi, grapes and persimmons.
- Consider following the Mediterranean Diet
- Avoid being overweight and avoid saturated fats
- Use UV400 sunglasses when outside
3. Intake of Vegetables, Fruit, and Fish is Beneficial for Age-Related Macular Degeneration, de Koning-Backus, Alexandra P.M. et al., American Journal of Ophthalmology, February 2019, Volume 198 , 70 – 79
4. Mediterranean Diet and Incidence of Advanced Age-Related Macular Degeneration, Merle, Bénédicte M.J. Ajana, Soufiane et al., Ophthalmology, Volume 126 , Issue 3 , 381 - 390
5. Oily fish consumption, dietary docosahexaenoic acid and eicosapentaenoic acid intakes, and associations with neovascular age-related macular degeneration, Cristina Augood et al, The American Journal of Clinical Nutrition, Volume 88, Issue 2, August 2008, Pages 398–406
6. W C Willett, F Sacks, A Trichopoulou, G Drescher, A Ferro-Luzzi, E Helsing, D Trichopoulos, Mediterranean diet pyramid: a cultural model for healthy eating, The American Journal of Clinical Nutrition, Volume 61, Issue 6, June 1995, Pages 1402S–1406S