Vision challenges are a common issue among Americans. Over 3.4 million adults aged 40 and older are either blind or experiencing visual impairments. Broader estimates indicate that as many as 21 million people in the U.S. face vision problems, with approximately 80 million at risk for serious eye diseases that could result in blindness. The major culprits behind vision impairment and blindness in older individuals include cataracts, age-related macular degeneration (AMD), diabetic retinopathy, and glaucoma. While conventional treatments like surgery exist for certain conditions, many also explore dietary supplements in hopes of preventing or slowing the progression of these eye issues.

The Scientific Perspective

Age-Related Macular Degeneration

AMD primarily affects people over 50, gradually damaging the macula, which is vital for sharp central vision. Though there are no available treatments for early-stage AMD, interventions can slow the progression of advanced AMD, potentially preventing further vision loss. Two landmark studies—earlier in 2001 with around 4,800 participants and a follow-up in 2013—have explored the role of dietary supplements in addressing AMD. These studies, referred to as AREDS (Age-Related Eye Disease Study) and AREDS2, examined the impact of specific supplements on delaying AMD progression, with over 4,000 adults aged 50-85 participating in the AREDS2 study.

• The original AREDS study revealed that a supplement containing high doses of vitamins C and E, beta-carotene, zinc, and copper helped slow AMD progression. However, concurrent studies identified an increased risk for lung cancer in smokers taking beta-carotene.
• AREDS2 assessed variations of the original supplement formula for people at risk of advanced AMD. Modifications included removing beta-carotene, adjusting zinc levels, and adding omega-3 fatty acids (from fish oil), lutein, and zeaxanthin (two key carotenoids). Smokers weren’t assigned beta-carotene because of its cancer risks, but some nonsmokers and ex-smokers were. The supplement’s effectiveness was not improved by omega-3 fatty acids, and reducing zinc didn’t diminish benefits. Additionally, beta-carotene was linked to a higher risk of lung cancer among former smokers, while lutein and zeaxanthin did not pose that threat. In fact, after a 10-year follow-up, lutein and zeaxanthin proved more effective than beta-carotene at reducing the progression of AMD.
• A comprehensive review in 2015, analyzing two clinical trials with over 2,300 participants, showed no significant benefits of omega-3 fatty acids in lowering the risk of AMD progression or vision loss severity.
• Many observational studies across the U.S., Europe, and Australia have pointed to a link between healthier diets (like the Mediterranean diet) and lower instances of advanced AMD. However, these associations weren’t as strong for early stages of AMD.

Cataracts

Cataracts develop when the lens of the eye becomes cloudy, leading to vision blurring and discoloration. In cases where cataracts impair daily activities, surgery often offers relief through lens replacement.

• In 2015, findings from a large randomized trial involving over 11,000 men (the SELECT study) concluded that long-term supplementation with selenium and vitamin E didn’t have a notable impact on age-related cataracts.
• A 2014 Swedish study with over 30,600 women suggested that antioxidants in the diet might help prevent cataracts. However, a 2012 review that assessed nine clinical trials (with nearly 117,300 participants) found no meaningful benefit from antioxidant vitamins like C, E, or beta-carotene in preventing or slowing the development of cataracts.
• The AREDS2 findings indicated that none of the modified formulas used in the study significantly reduced the need for cataract surgery; however, participants with lower levels of dietary lutein and zeaxanthin seemed to experience some protection.

Diabetic Retinopathy

Diabetic retinopathy occurs when the blood vessels in the retina are damaged due to diabetes, potentially distorting or even obscuring vision.

• An overview of research published in 2011 confirmed that no dietary supplements had been proven effective in preventing or treating diabetic retinopathy.

Glaucoma

Glaucoma threatens vision by damaging the optic nerve, particularly affecting side (peripheral) vision. Early detection and standard treatments are critical for managing this condition.

• To date, there is limited evidence to support the use of high-dose vitamins, special diets, acupuncture, relaxation techniques, or therapeutic touch as effective treatments for glaucoma.

Potential Side Effects and Risks

• Always follow your eye care professional's advice. It’s important not to substitute conventional treatments with unproven or experimental methods.
• Supplements such as antioxidants and zinc may only be appropriate for specific cases of advanced AMD. Consult your doctor to determine if they’re appropriate for your condition.
• Be cautious with beta-carotene supplements, especially if you're a current or former smoker, as they could elevate lung cancer risks.
• Improper use of supplements or taking them in excessive amounts may result in health issues, and some supplements could interfere with other medications.

For further details on maintaining good eye health, visit the National Eye Institute (NEI) website.

Accessing Additional Information

NCCIH Clearinghouse

The NCCIH Clearinghouse offers valuable information about complementary and integrative health approaches, including scientific research. Please note that the Clearinghouse doesn’t provide personalized medical advice, treatment recommendations, or healthcare provider referrals.

Toll-free (U.S.): 1-888-644-6226

Telecommunications relay services (TRS): 7-1-1

Website: https://www.nccih.nih.gov

Email: [email protected]

Know the Science

NCCIH and the National Institutes of Health offer tools to help you comprehend scientific research, enhancing your ability to make informed health decisions. The 'Know the Science' section includes interactive content, quizzes, and video resources, guiding you to understand scientific concepts and terminology.

Resources include:

• Explaining How Research Works (NIH)
• Know the Science: How To Make Sense of a Scientific Journal Article
• Understanding Clinical Studies (NIH)

PubMed®

Hosted by the National Library of Medicine, PubMed® provides detailed information and abstracts on research articles published in scientific and medical journals. For assistance from NCCIH on leveraging PubMed, check out their guide on finding complementary health information.

Website: https://pubmed.ncbi.nlm.nih.gov/

This document is publicly available and can be freely duplicated.

NCCIH provides this content for educational purposes and not as a substitute for professional medical advice. Always discuss any treatment decisions with healthcare professionals. Mention of any product, service, or therapy doesn’t imply endorsement from NCCIH.