March 14, 2007 -- You may not want to count on beta-carotene pills to prevent age-related macular degeneration (AMD).
A new study in Archives of Ophthalmology shows that healthy men taking beta-carotene pills for 12 years were as likely to develop age-related maculopathy (ARM), which includes AMD, as men not taking beta-carotene pills.
AMD is America's leading cause of vision loss, affecting more than 13 million people in the U.S. It's uncommon in people younger than 55.
AMD targets the macula, a part of the retina that enables you to read, watch TV, drive, sew, or do anything else that requires focused, precise vision. AMD gradually damages the macula.
Vitamin and Vision Study
The new study included about 22,000 apparently healthy U.S. male doctors who were 40-84 years old at the study's start.
The researchers -- who included William Christen, ScD, of the division of preventive medicine at Brigham and Women's Hospital in Boston -- randomly split the men into two groups.
One group of men was assigned to take a pill containing 50 milligrams of beta-carotene every other day. The other group received a sham pill (placebo) containing no beta-carotene.
The men were followed for 12 years. Most took their pills dutifully during that time. Every year, they updated their medical history.
The men didn't have to get their eyes examined for the study, but the researchers did try to confirm reported ARM diagnoses.
At the end of the study, 162 men in the beta-carotene group and 170 in the placebo group had developed ARM. The difference between the two groups was so small that it could have been due to chance.
During the study, the men in the placebo group were allowed to take their own vitamins if they wanted to. Nearly 6% of the men in the placebo group took vitamins containing beta-carotene. That probably didn’t skew the results, the researchers note.
The findings held when Christen and colleagues adjusted for the men's age and other risk factors.
Long-term use of beta-carotene supplements doesn't raise or lower the odds of developing ARM, the researchers conclude.