Macular Degeneration

In a double-blind study, supplementation with a proprietary blend of acetyl-L-carnitine, omega-3 fatty acids from fish oil, and coenzyme Q10 for 12 months resulted in an improvement in both visual function and in objective findings on eye examination (a decrease in the drusen-covered area on the retina).²

Ginkgo(Ginkgo biloba) may help treat early-stage macular degeneration, according to small, preliminary clinical trials.³ Many healthcare professionals recommend 120 to 240 mg of standardized extract (24% ginkgo flavone glycosides and 6% terpene lactones) in capsules or tablets per day.

Lutein and zeaxanthin are antioxidants in the carotenoid family. These carotenoids, found in high concentrations in spinach, collard greens, and kale, have an affinity for the part of the retina where macular degeneration occurs. Once there, they protect the retina from damage caused by sunlight.⁴

Harvard researchers reported that people eating the most lutein and zeaxanthin—an average of 5.8 mg per day—had a 57% decreased risk of macular degeneration, compared with people eating the least.⁵ While spinach and kale eaters have a lower risk of macular degeneration, blood levels of lutein did not correlate with risk of macular degeneration in one trial.^6,7 In a double-blind study of people with macular degeneration, supplementation with lutein (10 mg per day) for one year significantly improved vision, compared with a placebo.⁸ Lutein was beneficial for people with both early and advanced stages of the disease. Lutein and zeaxanthin can be taken as supplements; 6 mg per day of lutein may be a useful amount.

In a preliminary trial, supplementation with melatonin (3 mg per day at bedtime for at least three months) resulted in an improvement in the abnormalities observed on eye examination in the majority of cases.⁹ Melatonin is believed to work by regulating eye pigmentation (and, consequently, the amount of light reaching the retina) and by functioning as an antioxidant.

In a blinded six-month study of people with macular degeneration, vision was the same or better in 88% people who took a nutritional supplement, compared with 59% of those who refused to take the supplement (a statistically significant difference). The supplement used in this study contained beta-carotene, vitamin C, vitamin E, zinc, copper, manganese, selenium, and riboflavin.¹⁰ People wishing to take all of these nutrients may supplement with a multivitamin-multimineral formula.

In a double-blind study of female health professionals who had cardiovascular disease or cardiovascular disease risk factors, daily supplementation with folic acid (2.5 mg), vitamin B6 (50 mg), and vitamin B12 (1 mg) for 7.3 years significantly decreased the incidence of age-related macular degeneration.¹¹ 

Two important enzymes in the retina that are needed for vision require zinc. In a double-blind trial, supplementation with 45 mg of zinc per day for one to two years significantly reduced the rate of visual loss in people with macular degeneration.¹² However, in another double-blind trial, supplementation with the same amount of zinc did not prevent vision loss among people with a particular type of macular degeneration (the exudative form).¹³

Caution: Synthetic beta-carotene has been linked to increased risk of lung cancer in smokers. Until more is known, smokers should avoid all beta-carotene supplements.

Sunlight triggers oxidative damage in the eye, which in turn can cause macular degeneration.¹⁴ Animals given antioxidants—which protect against oxidative damage—have a lower risk of this vision problem.¹⁵ People with high blood levels of antioxidants also have a lower risk.¹⁶ Those with the highest levels (top 20th percentile) of the antioxidants selenium, vitamin C, and vitamin E may have a 70% lower risk of developing macular degeneration, compared with people with the lowest levels of these nutrients (bottom 20th percentile).¹⁷ People who eat fruits and vegetables high in beta-carotene, another antioxidant, are also at low risk.¹⁸ Some doctors recommend antioxidant supplements to reduce the risk of macular degeneration; reasonable adult levels include 200 mcg of selenium, 1,000 mg of vitamin C, 400 IU of vitamin E, and 25,000 IU of natural beta-carotene per day. However, a preliminary study found no association between age-related macular degeneration and intake of antioxidants, either from the diet, from supplements, or from both combined.¹⁹ Moreover, in a double-blind study of male cigarette smokers, supplementing with vitamin E (50 IU per day), synthetic beta-carotene (about 33,000 IU per day), or both did not reduce the incidence of age-related macular degeneration.²⁰

Bilberry’s active flavonoid compounds, anthocyanosides, act as antioxidants in the retina of the eye. Therefore, supplementing with bilberry would theoretically be of value for the prevention or treatment of early-stage macular degeneration.²¹ Bilberry has also been shown to strengthen capillaries and to reduce bleeding in the retina.²² A typical amount of bilberry used in studies was 480–600 mg per day of an extract standardized to contain 25% anthocyanosides, taken in capsules or tablets.

Lutein and zeaxanthin are antioxidants in the carotenoid family. These carotenoids, found in high concentrations in spinach, collard greens, and kale, have an affinity for the part of the retina where macular degeneration occurs. Once there, they protect the retina from damage caused by sunlight.²³

Harvard researchers reported that people eating the most lutein and zeaxanthin—an average of 5.8 mg per day—had a 57% decreased risk of macular degeneration, compared with people eating the least.²⁴ While spinach and kale eaters have a lower risk of macular degeneration, blood levels of lutein did not correlate with risk of macular degeneration in one trial.^25,26 In a double-blind study of people with macular degeneration, supplementation with lutein (10 mg per day) for one year significantly improved vision, compared with a placebo.²⁷ Lutein was beneficial for people with both early and advanced stages of the disease. Lutein and zeaxanthin can be taken as supplements; 6 mg per day of lutein may be a useful amount.

Goji berries are also a rich source of zeaxanthin, a carotenoid that when consumed becomes concentrated in the macular pigment of the eye and may help protect the retina.^29,30 Both human and monkey studies have shown that consuming goji berries or extracts high in zeaxanthin raises blood levels of zeaxanthin,^31,32,33,34 but only animal research has verified that goji berry consumption increases macular pigment, and no research has looked at whether goji berries provide protection from diseases of the retina.

Sunlight triggers oxidative damage in the eye, which in turn can cause macular degeneration.³⁵ Animals given antioxidants—which protect against oxidative damage—have a lower risk of this vision problem.³⁶ People with high blood levels of antioxidants also have a lower risk.³⁷ Those with the highest levels (top 20th percentile) of the antioxidants selenium, vitamin C, and vitamin E may have a 70% lower risk of developing macular degeneration, compared with people with the lowest levels of these nutrients (bottom 20th percentile).³⁸ People who eat fruits and vegetables high in beta-carotene, another antioxidant, are also at low risk.³⁹ Some doctors recommend antioxidant supplements to reduce the risk of macular degeneration; reasonable adult levels include 200 mcg of selenium, 1,000 mg of vitamin C, 400 IU of vitamin E, and 25,000 IU of natural beta-carotene per day. However, a preliminary study found no association between age-related macular degeneration and intake of antioxidants, either from the diet, from supplements, or from both combined.⁴⁰ Moreover, in a double-blind study of male cigarette smokers, supplementing with vitamin E (50 IU per day), synthetic beta-carotene (about 33,000 IU per day), or both did not reduce the incidence of age-related macular degeneration.⁴¹

Sunlight triggers oxidative damage in the eye, which in turn can cause macular degeneration.⁴² Because vitamin C functions as an antioxidant, it has the potential to protect against macular degeneration. However, in a double-blind trial, supplementing with 500 mg of vitamin C daily for eight years did not decrease the incidence of macular degeneration in healthy male physicians.⁴³

Sunlight triggers oxidative damage in the eye, which in turn can cause macular degeneration.⁴⁴ Animals given antioxidants—which protect against oxidative damage—have a lower risk of this vision problem.⁴⁵ People with high blood levels of antioxidants also have a lower risk.⁴⁶ Those with the highest levels (top 20th percentile) of the antioxidants selenium, vitamin C, and vitamin E may have a 70% lower risk of developing macular degeneration, compared with people with the lowest levels of these nutrients (bottom 20th percentile).⁴⁷ People who eat fruits and vegetables high in beta-carotene, another antioxidant, are also at low risk.⁴⁸ Some doctors recommend antioxidant supplements to reduce the risk of macular degeneration; reasonable adult levels include 200 mcg of selenium, 1,000 mg of vitamin C, 400 IU of vitamin E, and 25,000 IU of natural beta-carotene per day. However, a preliminary study found no association between age-related macular degeneration and intake of antioxidants, either from the diet, from supplements, or from both combined.⁴⁹ Moreover, in a double-blind study of male cigarette smokers, supplementing with vitamin E (50 IU per day), synthetic beta-carotene (about 33,000 IU per day), or both did not reduce the incidence of age-related macular degeneration.⁵⁰ Another double-blind trial found that supplementing with 600 IU of vitamin E every other day did not reduce the incidence of age-related macular degeneration in healthy women.⁵¹