Q. Who should take the combination of antioxidants and zinc like those used in the Age-Related Eye Disease Study?
People who should consider taking the combination of antioxidants plus zinc include those who are at high risk for developing advanced AMD. These people are defined as having either:
Intermediate AMD in one or both eyes. Intermediate AMD is defined as the presence of either many medium-sized drusen or one or more large drusen.
Advanced AMD in one eye, but not the other eye. Advanced AMD is defined as either a breakdown of light-sensitive cells and supporting tissue in the central retinal area (advanced dry form), or the development of abnormal and fragile blood vessels under the retina (wet form) that can leak fluid or bleed. Either of these forms of advanced AMD can cause vision loss.
Q. How do I know if I have AMD and the stage it is in?
Your ophthalmologist or optometrist can tell you if you have AMD -- and its level of development -- through an eye exam in which drops are placed in the eyes to dilate the pupils. This allows for a careful examination of the inside of the eye.
Q. I am already taking daily vitamins. Should I stop taking these vitamins if I am advised to take the combination of antioxidants plus zinc evaluated by the Age-Related Eye Disease Study?
People with intermediate AMD in one or both eyes, or those with advanced AMD in one eye only, and who are advised to take a formulation like those used in the AREDS, should review the supplements they are taking with their primary care doctors and/or eye care professionals. In addition to their study medication, most of the participants in the AREDS took a multivitamin that contained the approximate recommended dietary allowance of most vitamins and minerals. Some multivitamin supplements are available that remove the compounds in AREDS vitamins, and are therefore complementary. One example is Co-Defense.
Q. How do people obtain the formulation in the dosages used by the AREDS researchers? Will it be available in tablet form in drug stores?
Bausch & Lomb, an eye care company, was a collaborator in the AREDS and AREDS 2 studies and provided the study formulations. The company markets the formulation used in the AREDS, Ocuvite Preservision; other companies provide similar formulations. Some examples are VisiVite, and ICaps. Antioxidant vitamins and zinc can also be purchased separately; however, consumers should discuss the use of these high levels of vitamins and minerals with their doctors, and be certain to include copper whenever taking high levels of zinc.
Q. Will the formulation come in three forms: "antioxidants plus zinc," "zinc alone," and "antioxidants alone?" How will I know what to take?
Those who are advised by their primary care doctors to take the AREDS' "zinc alone" or "antioxidant alone" formulations, as well as those who choose to purchase the "antioxidants plus zinc" formulation from another manufacturer, should compare the labels of those products with the AREDS formulations. Antioxidant and zinc formulations can also be purchased separately; however, consumers should discuss the use of these high levels of vitamins and minerals with their doctors, and be certain to include copper whenever taking high levels of zinc. Your primary care doctor can help you determine which formulation and dose is best for you.
Q. Are there reasons older people, in particular, should be cautious in supplementing their diets with the nutrients and doses used in the AREDS?
Yes. There are reasons to be cautious in using high-dose vitamins and minerals, particularly among older people. Many older Americans take prescription medications, and a considerable number use over-the-counter drugs, dietary supplements, and herbal medicines. High-dose nutrients can interfere with medications and interact with other nutrients to decrease the nutrients' absorption into the body. This can ultimately affect a person's nutritional and health status. For example, the zinc concentration in the AREDS formulation is at a very high dose and could cause copper deficiency anemia. To prevent this, copper was added to the AREDS formulation. People who are being treated for chronic diseases such as cancer, heart disease, and diabetes should not take high dose nutrients without talking with their doctors. Generally, self-medication with high doses of vitamins and minerals -- such as those in the AREDS and AREDS 2 formulations -- is not recommended. Individuals who are considering taking the AREDS2 formulation should discuss this with their primary care doctors and/or eye care professionals. They can help you determine which formulation and dosages are best for you.
Q. If I have been diagnosed with early AMD, should I take the nutrients to help prevent disease progression to the intermediate stage?
There is no apparent need for those diagnosed with early AMD to take the nutrients studied in the AREDS. This is because the study did not demonstrate that the nutrients provided a benefit to those with early AMD. Many people with early AMD progressed to intermediate AMD during the study, and the AREDS formulation did not seem to slow this progression. However, if you have early AMD, a dilated eye examination every year can help determine whether the disease is progressing.
Q. How long will I have to take the nutrients?
The AREDS researchers followed participants for an average of 6.3 years (with a maximum of eight years), and AREDS2 was 5 years long, so the effectiveness of the nutrients beyond this time is unknown.
Q. What are the side effects from the AREDS and AREDS 2 formulations?
The AREDS participants reported few side effects from the treatments. About 7.5 percent of participants assigned to the zinc treatments -- regardless of whether they were the "antioxidants plus zinc" or "zinc alone" treatment -- experienced genitourinary problems that required hospitalization. Some of these problems included urinary tract infections, kidney stones, incontinence, and enlarged prostate. This compares with five percent of participants who did not have zinc in their assigned treatment that experienced the same genitourinary problems. Participants in the two groups that took zinc also reported anemia at a slightly higher rate; however, testing of all patients for this disorder showed no difference among treatment groups. Yellowing of the skin, a well-known side effect of large doses of beta-carotene, was reported slightly more often by participants taking antioxidants.