The original formulation of the nutritional supplement AREDS was recommended for the prevention of age-related eye disease and included beta-carotene, which has been associated with an increased risk of lung cancer in former smokers and people who smoke, reports the National Eye Institute. In one study, 2 percent of those who took the supplement developed lung cancer, compared to 0.9 percent who took a formula with no beta-carotene. Of these, 91 percent were former smokers.Continue Reading
Additionally, the high-dose vitamin E in both the original and revised AREDS formulas was associated with a 17-percent increased risk of prostate cancer in a 2011 study, states the National Eye Institute. However, a 1994 study showed that men taking 50 milligrams of vitamin E daily had a 35-percent reduction in the risk of prostate cancer, while a study in 2009 showed that a similar dose of vitamin E had no effect on the risk of prostate cancer.
Other rare side effects of the original AREDS formula include bleeding, blood clots, joint pain, nausea, diarrhea and yellow discoloration of the skin, reports WebMD. High doses of vitamins and minerals may also interfere with the actions of some medications, explains the National Eye Institute.
The original AREDS formula contained vitamin C, vitamin E, beta-carotene, copper and zinc, according to the National Eye Institute. The revised formula, in which the beta-carotene was removed, also contains 10 milligrams of lutein, 2 milligrams of zeaxanthin and 1,000 milligrams of omega-3 fatty acids, as well as a lower dose of zinc. The revised formula has been shown to reduce the risk of advanced age-related macular degeneration in people who already have the disease.Learn more about Side Effects