Statins, the cholesterol-lowering drugs taken by millions of Americans, might also reduce the risk of cataracts, a preliminary study suggests.
Adults who took statins were found to be 45 percent less likely to develop the most common type of age-related cataracts.
Other researchers warned that something other than statins might explain the results and that the study does not prove cause-and-effect.
The results were a surprise because of earlier concerns that some cholesterol medication might increase the risk of cataracts, a common clouding-over of the lens of the eye that can lead to poor vision and blindness. In fact, several cholesterol drugs never made it to market because of those concerns.
The study, published in Wednesday’s Journal of the American Medical Association, involved 1,299 Beaver Dam, Wis., residents who were followed for five years.
Nuclear cataracts — which affect the eye lens nucleus — were diagnosed in more than 200 participants, or in about 12 percent of statin users, compared with 17 percent of nonusers. After factoring in the participants’ age, the researchers concluded that statin users were about 45 percent less likely to develop nuclear cataracts.
“It was pretty surprising,” said lead author Dr. Barbara Klein, an eye researcher at the University of Wisconsin in Madison.
There were no statistically significant differences in rates for two other less common types of cataracts.
Statins, which are taken by millions of Americans and include such top-selling drugs as Lipitor, Pravachol and Zocor, dramatically lower levels of artery-clogging bad cholesterol.
Statins have also been reported to have antioxidant benefits and to attack inflammation. And both oxygen damage to the body and inflammation are believed to be related to cataracts.
More than 20 million have cataracts
Cataracts affect more than 20 million Americans and are a major cause of vision impairment and blindness worldwide. Most are associated with aging; more than half of U.S. adults in their 70s and older are affected.
Cataracts are usually treated with surgery, typically an outpatient procedure in which the clouded lens is replaced with an artificial lens. Cataract removal is among the most common U.S. operations; by some estimates more than 1 million Americans undergo it each year. The surgery is often covered by insurance.
In the latest study, the statin-cataract relationship remained strong even when the researchers factored in whether participants smoked, a habit that is linked to the development of cataracts.
But Debra Schaumberg, an eye specialist at Harvard’s Brigham and Women’s Hospital, cautioned against over-interpreting the results.
“While I agree with the authors that the potential for a relatively benign and inexpensive preventive therapy for cataract would have substantial public health importance, I think it is still far too early to assign any such role to statin medications,” she said.
Similarly, researcher Natalie Kurinij of the National Eye Institute, which helped fund the study, said the study does not mean people should take statins to ward off cataracts.
“There was no information on duration of use or the doses used. You would really need that kind of information in order to make a definitive call,” she said.
The Research to Prevent Blindness, a New York-based foundation, also contributed funding for the study.