Long-term daily multivitamin supplement use can lower the cataract risk in men, suggest researchers.
Researchers based at Brigham and Women's Hospital and Harvard Medical School - as part of the Physicians' Health Study II (PHS II) - conducted a randomized, double-blind study from 1997 to 2011 of 14,641 U.S. male doctors age 50 and older.
Half took a common daily multivitamin, as well as vitamin C, vitamin E and beta carotene supplements. The other half took a placebo. The researchers followed the participants to identify how many participants in each group developed new cases of two common eye diseases: cataract, which is a clouding of the eye's lens, and age-related macular degeneration (AMD), the deterioration of the eye's macula that is responsible for the ability to see fine details clearly.
The researchers found that in the placebo group 945 cases of cataract developed, which were self-reported and confirmed by medical records, while only 872 cases of cataract developed in the multivitamin group, representing a 9 percent decrease in risk.
This risk was even lower, at 13 percent, for nuclear cataract, which occurs at the center of the lens and is the most common variety of cataract associated with the aging process.
William Christen, ScD, the study's lead author and researcher from Harvard Medical School, said that if multivitamins really do reduce the risk of cataract, even by a modest 10 percent, this rather small reduction would nonetheless have a large public health impact.
The study has been published in journal Ophthalmology.