The AREDS 2 formulation is a specific blend of vitamins and minerals designed to slow the progression of intermediate and advanced age-related macular degeneration (AMD). However, because of the high concentration of nutrients, it is not appropriate for all individuals. Factors ranging from smoking history to pre-existing medical conditions and certain genetic traits can make these supplements potentially harmful or ineffective.
Smokers and Former Smokers
For smokers and those who have recently quit, the primary concern is with the beta-carotene found in the original AREDS formula, not the revised AREDS 2 formula. Studies found that beta-carotene could increase the risk of lung cancer in this population. For this reason, AREDS 2 replaced beta-carotene with lutein and zeaxanthin, which have not been associated with this risk.
Crucial distinction for smokers:
- Original AREDS: Contained beta-carotene and should be avoided by smokers and former smokers.
- AREDS 2: Formulated without beta-carotene, making it a safer option for smokers and former smokers seeking AMD treatment. However, users must ensure they are purchasing a genuine AREDS 2 formulation, as some companies may still include beta-carotene in 'eye health' vitamins.
Patients on Anticoagulant Medication
Individuals taking blood-thinning medications, such as warfarin (Coumadin), or antiplatelet drugs like aspirin and clopidogrel, should exercise caution with AREDS 2 supplements.
- The high dose of vitamin E (400 IU) in the AREDS 2 formulation can increase the risk of bleeding by enhancing the effects of these medications.
- Patients on blood thinners should always consult their doctor or pharmacist before starting AREDS 2.
- Some manufacturers offer AREDS 2 formulations without vitamin E specifically for patients with bleeding risks.
Individuals with Specific Health Conditions
Certain medical conditions can be exacerbated by the high doses of vitamins and minerals in AREDS 2.
- Kidney or Liver Disease: The body's ability to process and excrete high levels of fat-soluble vitamins (like Vitamin E) and minerals (like zinc) can be impaired in individuals with kidney or liver disease. This can lead to a dangerous build-up of these nutrients. Patients with Chronic Kidney Disease (CKD) should avoid high-dose supplements unless prescribed by a specialist.
- Gastrointestinal Distress: The high dose of zinc (80 mg) in standard AREDS 2 formulas can cause nausea, vomiting, or stomach upset in some people, particularly when taken on an empty stomach.
Individuals Unlikely to Benefit from AREDS 2
AREDS 2 is a targeted treatment, and not all patients with eye conditions will benefit. The studies specifically showed benefits for slowing AMD progression, not preventing other vision issues.
- Early-Stage AMD: The benefits of AREDS 2 are proven for individuals with intermediate or late-stage AMD. There is no evidence that the supplements help people with early AMD or those without the condition.
- Cataracts: While the original AREDS study investigated the effect of the supplements on cataracts, no benefit was found. The AREDS 2 study also found no overall effect on cataract progression.
- Glaucoma: AREDS 2 vitamins are not designed to treat or prevent glaucoma and have no effect on the condition.
Potential Drug Interactions and Genetic Considerations
The high mineral content of AREDS 2 can interact with other medications and may have varied effects based on individual genetics.
- Antibiotics: Zinc can interfere with the absorption of certain antibiotics, like tetracyclines and quinolones. Spacing the intake of the supplement and medication by a few hours can minimize this issue.
- Bisphosphonates: Used to treat osteoporosis, bisphosphonates can have their absorption affected by the high levels of zinc in AREDS 2.
- Genetic Polymorphisms: Research suggests that certain genetic variations, such as those in the CFH and ARMS2 genes, can alter how an individual responds to zinc supplementation. For some, high zinc may have a negative effect or provide no benefit, while others may experience maximum benefit.
A Comparison of Who Should and Should Not Take AREDS 2
| Factor | Who Should Take AREDS 2 | Who Should NOT Take AREDS 2 (or with caution) |
|---|---|---|
| Stage of AMD | Intermediate or advanced AMD in one or both eyes. | Early-stage AMD or no AMD. |
| Smoking History | All individuals, provided they are taking a certified beta-carotene-free AREDS 2 formula. | Smokers/former smokers taking an AREDS 1 formula or unverified supplement containing beta-carotene. |
| Medication | Not on blood-thinning medications or antibiotics. | On blood thinners (e.g., warfarin) or antibiotics. |
| Underlying Health | Generally healthy liver and kidney function. | Chronic kidney or liver disease. |
| Side Effects | Not experiencing significant gastrointestinal issues. | Experiencing nausea, vomiting, or stomach upset due to high zinc. |
| Genetic Profile | Individual response to zinc is positive or neutral (should consult specialist). | Specific genetic variations (CFH/ARMS2) that cause a negative response to zinc. |
| Condition Treated | Slowing the progression of AMD. | Preventing cataracts or treating glaucoma. |
Conclusion
For individuals diagnosed with intermediate to advanced age-related macular degeneration, the AREDS 2 formulation offers a proven path to slow the disease's progression. However, its high concentration of specific vitamins and minerals means it is not a one-size-fits-all solution. Patients on blood-thinning medication, those with kidney or liver disease, and individuals concerned about genetic predisposition or drug interactions must approach supplementation with caution. Most importantly, AREDS 2 is not a preventative measure for healthy eyes or a treatment for other eye conditions like cataracts or glaucoma. Always consult a healthcare provider or ophthalmologist to confirm if AREDS 2 is right for your specific health profile before beginning supplementation.
For more information on the Age-Related Eye Disease Studies, visit the National Eye Institute website.
