February is age-related macular degeneration (AMD) awareness month. The macula is the center of your retina, where your finest vision occurs. While AMD is the leading cause of blindness among older adults, it won’t necessarily cause complete vision loss. Instead, imagine wearing a pair of glasses that is the wrong prescription for you. If you’ve ever experienced this, you know that it can be a disorienting experience.
Though nutrition doesn’t appear to halt the progression from early to intermediate AMD, it does decrease the risk of developing severe disease–just one more reason to stock up on produce.
Dry vs. Wet Macular Degeneration
Most macular degeneration begins with the “dry” form in middle age. The first step in the development is the development of yellow deposits under the macula (known as drusen). Drusen is primarily composed of leftover oxidized fats that accumulate under the retina. Over time, drusen grow, and the macula thins. The rods and cones, along with the pigment epithelial cells, die. Once this occurs, the center of your vision might become wavy or seem fuzzy, you may find that you have difficulty seeing people’s faces, and your night vision might suffer.
Sometimes, but not always, dry AMD progresses to wet AMD. About ten percent of people with dry AMD develop wet AMD. In wet AMD, abnormal blood vessels grow under the retina. These vessels leak blood and fluid, which causes bulging, swelling, and permanent scarring of the macula. Wet AMD can cause blind spots, distortions, and color blindness.
Risk Factors for Age-Related Macular Degeneration
- Family history
- High blood pressure
- High cholesterol
- Eating lots of saturated fat
- Being light-skinned
- Having light-colored eyes
- Being female
- Sun exposure
- A sedentary lifestyle
- Certain medications, including some antipsychotics and malaria treatments
Treatment of Macular Degeneration
Although there is no cure for macular degeneration, appropriate treatment can slow the progression or prevent further vision loss. Treatment options include:
- Anti-angiogenesis drugs (examples include Eyelea, Avastin, Macugen, and Lucentis) block the proliferation of blood vessels and stop leaking from those vessels.
- Laser therapy can destroy any abnormal blood vessels that have already formed.
- Scientists and doctors are experimenting with submacular surgery to remove abnormal blood vessels or blood built up in the eye. Retinal translocation destroys abnormal blood vessels in a part of the eye that a laser beam can’t reach.
Nutrition for Macular Degeneration
The National Eye Institute suggests vitamin supplements for intermediate AMD in one or both eyes or advanced AMD in one eye. For these people, supplementation might lower the risk of severe disease by 25 percent. Unfortunately, there is no evidence that supplementation will slow the profession from early to intermediate macular degeneration.
There is evidence that a healthy diet can also lower the risk of developing macular degeneration. For example, in one study published in the American Journal of Clinical Nutrition, eating an orange a day was associated with a 60% risk reduction.
The AREDS Study
These recommendations are based on the Age-Related Eye Disease Study (AREDS); 5,000 participants were enrolled in a study to discern the effects of vitamin and mineral supplementation on age-related macular degeneration. The results showed that a daily supplement had reduced the progression of the eye disease. The original supplement consisted of:
- Vitamin C (500 mg)
- Vitamin E (400 IU)
- Beta-carotene (15 mg)
- Zinc (80 mg)
- Copper (2 mg)
The AREDS2 Study
In the second AREDS study, researchers added omega-3 fatty acids and the antioxidants lutein and zeaxanthin to see if the risk of AMD would be further reduced with their inclusion. They also eliminated beta-carotene from the supplements.
Vitamin A, manufactured from the beta-carotene in food, supports the photoreceptor cells in the eyes that allow you to see bright colors and aid your night vision. Beta-carotene is no longer recommended in supplemental form because it appears to increase the risk of lung cancer in people who once smoked. It has also been found to block the absorption of lutein, a nutrient that is of great benefit for halting the progression of AMD. However, eating foods rich in this nutrient is recommended and poses no risk, regardless of smoking history.
Also, the participants given zinc in the original AREDS study had an increase in enlarged prostate, stress incontinence, and hospitalizations for urinary tract infections. In AREDS 2, the researchers cut the amount of zinc in the supplements from 80 mg to 25 mg.
Omega-3 Fatty Acids
The omega-3 fatty acids surprisingly didn’t help the eyes as much as expected in slowing the progression of intermediate to advanced AMD in AREDS 2. Still, these fats are essential for eye health in other regards and should still be emphasized in a healthy diet. EPA and DHA, two of the three primary omega-3 fatty acids, are building blocks of the retina and prevent inflammation.
Feed Your Eyes
- Citrus fruits
- Vegetable oils
- Sunflower seeds
- Wheat germ
- Whole grains
- Turnip greens
- Wheat germ
- Fortified breakfast cereals
- Whole grains
- Dried fruit
Omega-3 Fatty Acids:
- Fatty fish including salmon, tuna, mackerel, trout, sardines, and anchovies
The carotenoids lutein and zeaxanthin are found in the macula, which is believed to minimize damage caused by light rays. In a 2015 JAMA Opthalmology study, consuming 5.5 mg of lutein and zeaxanthin daily can reduce the risk of developing advanced macular degeneration by 40 percent.
- Swiss chard
- Mustard greens
- Red peppers
- Orange sweet peppers
- Green leafy vegetables