If you have developed macular degeneration, you may have heard of taking zinc to slow this disease. But is that the best choice — and does it work?
Whether you are considering zinc or other vitamins and nutrients for eye health, here’s what you need to know. Sometimes the information we have available is contradictory, or research is unclear. That’s the case with zinc. It appears to help delay age-related macular degeneration (AMD) in some studies, but not in others.
But when we consider all the information available, the best research shows that zinc works best when you use it as part of a powerful combination, says ophthalmologist Amy Babiuch, MD.
She says, yes, a zinc supplement may help slow AMD, but the best supplement to take has a mix of nutrients, not just zinc as a single ingredient.
Studies support mix of vitamins, minerals
There’s no proven way to prevent the early stages AMD. However, two extensive clinical studies found that a specific mix of vitamins, antioxidants and zinc may delay progression of advanced AMD.
Taking this supplement can help you keep your vision longer if you have intermediate AMD, or advanced AMD in one eye.
The National Eye Institute sponsored both studies. The first, the Age-Related Eye Disease Study (AREDS) found that daily high doses of vitamin A and C, beta-carotene, zinc and copper could slow the progression of advanced AMD.
Emerging from the second study, researchers found no significant changes in effectiveness when they reduced the amount of zinc and replaced the beta-carotene with zeaxanthin and lutein.
Why researchers modified the formula
The updated formulation emerging from the second study is referred to as the AREDS2 formulation. In part, investigators reduced the zinc because some nutritionists worried about the high dose.
Known side-effects of taking too much zinc include nausea, stomach pains and a slightly higher rate of problems like urinary tract infections and kidney stones.
Experts say that based on the two studies, it is unclear how much zinc is truly necessary to have a positive effect. In the second trial, the zinc dosage was reduced to 25 milligrams (mg).
Also, in the second trial, researchers removed beta-carotene because of its link with an increased risk of lung cancer in former smokers. The results showed that other antioxidants, such as lutein and zeaxanthin, don’t pose the same risks and may offer better protective benefits against advanced AMD.
Over-the-counter vision protection
“Currently, we recommend the AREDS2 formulation which includes zinc, lutein and zeaxanthin,” says Dr. Babiuch.
When you’re shopping for a supplement, she suggests looking for one that specifically states on the label that it follows the AREDS2 formulation:
- 500 mg of vitamin C
- 400 international units of vitamin E
- 25 mg zinc as zinc oxide (reduced from 80 mg in initial study)
- 2 mg copper as cupric oxide
- 10 mg lutein
- 2 mg zeaxanthin
Dr. Babiuch also recommends talking to your doctor about the AREDS2 supplement before deciding to take it. Your doctor will help make sure it won’t interfere with your current prescriptions and other medications or vitamins that you take.