One of the numerous complications that affect eyesight as we get older is a condition called age-related macular degeneration (AMD).  This chronic eye disease affects as many as 15 million Americans and millions more around the world.  It’s the number one cause of severe vision loss and legal blindness of people over the age of 60 in the U.S.

Age-related macular degeneration is a life-altering, chronic eye disease that gradually destroys the macula, a small region in the center of the retina located at the back of the eye that is necessary for clear central vision. It leads to vision loss in the center of your field of vision but without usually affecting peripheral vision.  This change leads to the central field of view appearing blurry, distorted or dark. To get a better understanding of what people with AMD experience, place your fist at the bridge of your nose so everywhere you look is a blind spot.  This irreversible loss of central vision leads to difficulty in reading, driving, doing close-up work, recognizing faces and overall social isolation as people with AMD often feel uncomfortable in social situations.

Forms of AMD

There are two forms of AMD: dry and wet.  Ninety percent of people with AMD have the dry form.  It is characterized by a slow degeneration of the macula with a slower progression to vision loss.

Wet AMD progresses to a more advanced stage of severe vision loss since it causes swelling and rapid damage to the macula.  Wet AMD always begins as dry AMD.  However, dry AMD can changeover to wet AMD at any time.

Risk factors of AMD

·         Age – This is a major risk factor.  People over the age of 50 are at risk but AMD occurs more likely after age 60.

·         Smoking – People who smoke are twice as likely to develop AMD compared to non- smokers. 

·         Race – AMD is more common among Caucasians.

·         Family history and genetics – People with family members with AMD are at a higher risk.  Around 20 genes have been identified that increase the risk of AMD.

Nutritions role in affecting AMD

There is substantial evidence that eating high amounts of certain nutrients may help to prevent or slow the progression of AMD.  Back in the early 1990’s, a large, randomized clinical trial conducted by the National Institutes of Health’s National Eye Institute oversaw the Age-Related Eye Disease Study (AREDS) that provided data to support this information.  Then, a second study completed in 2013 (AREDS2) confirmed the role of supplements in preventing advanced AMD.  In fact, both studies established AMD as a “nutrition responsive disorder.” 

The findings of these studies were that two key nutrients – lutein and zeaxanthin - both are xanthophyll carotenoids and are important in reducing the risk of AMD.  The study using a formulation of high-dose antioxidants, including lutein and zeaxanthin, showed a 25 % reduction risk of developing advanced AMD and a 19% lower risk of central vision loss of people with intermediate or advanced disease.

Lutein and zeaxanthin filter harmful high-energy blue wavelengths of light and act as antioxidants in the eye, helping to protect and maintain healthy cells from environmental damage caused by smoking, pollutants and sun exposure. Both are found in high quantities in the macula of the eye.  The body cannot synthesize lutein or zeaxanthin making it necessary to obtain them daily through food or nutritional supplements. 

Currently, there is no recommended daily intake for lutein or zeaxanthin.  However to lower the risk of AMD, research has shown it takes at least 6 mg of lutein each day but the average adult takes in less than 2 mg of lutein a day.  Both AREDS and AREDS2 studies used supplementation of lutein at 10 mg a day and supplementation of zeaxanthin of 2 mg a day. 

Best food sources of both lutein and zeaxanthin:

Besides lutein and zeaxanthin additional nutrients for good eye health include:

·         Omega-3 fatty acids – These support eye health by preventing arterial plaque buildup and reduce inflammation and damage to blood vessels and cells.  Excellent food sources include cold water fish such as salmon, sardines, tuna, herring or cod liver oil.  Plant sources are found in walnuts, flaxseeds and dark green vegetables.

·         Zinc – This mineral is concentrated in the retina and is important in getting vitamin A from the liver to the retina to produce melanin, a protective pigment in the eye.  Good food sources are red meat, poultry, pork, seafood, eggs, nuts, wheat germ and tofu.

·         Vitamin C – This antioxidant slows the progression of AMD in addition to lowering the risk of developing cataracts.  It also supports the health of ocular blood vessels.  Best food sources include citrus fruits such as oranges, grapefruit, lemons and limes.  Other sources include tomatoes, potatoes, spinach and peppers such as green, red and orange.

·         Vitamin E – This powerful antioxidant helps to protect the cells of the eyes from damage caused by free radicals which are unstable molecules, which could lead to the breakdown of healthy tissue.  Rich food sources are almonds, peanuts, fortified cereals, sunflower seeds, sweet potatoes and vegetable oils.

In conclusion

A 2011 Harris survey found that 8 out of 10 Americans fear losing their vision – more than any other sense.  Any form of vision loss is devastating but there are steps we can take today to prevent this from happening.  Have an annual eye exam, eat a diet rich in lutein, zeaxanthin, omega-3 fatty acids, zinc, vitamin C and E or discuss with your eye doctor about a supplement containing these nutrients.  Doing so improves your chance of a clear, more in-focus future ahead. 

ABOUT CHERYL MUSSATTO, 

REGISTERED DIETITIAN

Cheryl Mussatto has over 30 years of experience as a Registered Dietitian and has worked in a variety of settings that cover a wide span of nutrition experience.  Currently she works as an adjunct professor for two community colleges, Allen Community College in Burlingame and Butler Community College in Council Grove, Kansas teaching two courses, Basic Nutrition and Therapeutic Nutrition. Cheryl also is a contributing author for osagecountyonline.com, an online newspaper and Edietitians, a global free nutritional and health magazine. Her articles for both publications pertain to nutrition topics that cover a diversity of health and nutrition interests for the general public.  She is also certified as a health and wellness coach.