Americans love nutritional supplements, and among the most popular supplements are vitamins designed to improve eye health. However, a new study shows that not all eye vitamins are created equal. Some do not contain the necessary amounts of key ingredients that have been shown to improve eye health, and some vitamin manufacturers make unsupported claims about their products.
The idea behind taking vitamins to improve eye health is a good one. The leading cause of blindness in the United States is due to a condition called age-related macular degeneration. This condition involves a deterioration of the central part of the retina — the macula — that enables clear vision. In 2001, a landmark scientific study called Age-Related Eye Disease Study, or AREDS, found that a specific formula of nutritional supplements containing high doses of antioxidants and zinc could slow macula deterioration.
A second study, AREDS2, conducted in 2011, further detailed the ingredients that seemed to help protect the eye. Those ingredients include:
- High doses of antioxidants (vitamins C and E)
In the new study, researchers identified the five top-selling brands based on market research and analyzed 11 products marketed under these five brands. They found:
- Only four of the products had equivalent doses of AREDS or AREDS2 ingredients
- Another four of the products contained lower doses of AREDS or AREDS2 ingredients
- Four of the products also included additional vitamins, herbs or minerals that are not part of the AREDS or AREDS2 formulas
All of the products’ promotional materials included claims that the supplements “support” or “promote” vision and eye health. However, none carried statements specifying that nutritional supplements have only been proven effective in people with specific stages of age-related macular degeneration. In fact, there is not sufficient scientific evidence that taking eye vitamins helps prevent other eye diseases such as cataracts or eye health in general.
“With so many vitamins out there claiming to support eye health, it’s very easy for patients to be misled into buying supplements that may not bring about the desired results,” said the first author of the study, Jennifer J. Yong, MD. “It’s also crucial that physicians remind patients that, at this time, vitamins have yet to be proven clinically effective in preventing the onset of eye diseases such as cataracts and AMD [age-related macular degeneration].”
However, for patients with intermediate or advanced age-related macular degeneration, the American Academy of Ophthalmology recommends doctors and patients consider antioxidant supplementation.
The new study was conducted by researchers at Yale-New Haven Hospital-Waterbury Hospital, Penn State College of Medicine, Providence VA Medical Center and Warren Alpert Medical School of Brown University.
“Ocular Nutritional Supplements: Are Their Ingredients and Manufacturers’ Claims Evidence-Based?” Ophthalmology, published online: Nov. 20, 2014