NEW YORK (Reuters Health) - People taking statins have a slightly lower risk of developing Parkinson's disease than those not on the cholesterol-lowering drugs, suggests a new study.
The findings don't mean that taking statins will ward off the degenerative movement disorder, and the researchers behind the new study say evidence that there's a link between the drugs and Parkinson's "remains unconvincing."
"Nobody should start or stop statins based on this result," Dr. Alberto Ascherio from the Harvard School of Public Health, one of the researchers, told Reuters Health.
About a quarter of adults age 45 and older in the United States take statins to lower cholesterol and ward off heart attacks. They run anywhere from $11 to more than $200 per month, and possible side effects include muscle pain, nausea and gas and liver dysfunction.
Over the years, researchers have tentatively tied the drugs to a lower risk of everything from some types of cancer to depression. But other studies have refuted the cancer link, and research has also suggested a possibly increased risk of diabetes in some patients taking statins.
Researchers had wondered if statins might increase the risk of Parkinson's disease because of their effect on an antioxidant that helps keep neurons alive. Studies on that topic have had mixed results, with no clear harm from statins showing up and at least a few finding a slight potential benefit.
In the latest trial to get at that question, Ascherio and his colleagues consulted records from two long-term studies of close to 130,000 health professionals.
Starting in 1986 or 1988, participants were surveyed every other year with questions including whether they were taking a cholesterol-lowering drug such as a statin. And throughout 1994 to 2006, researchers asked them to report whether they'd recently been diagnosed with any new conditions, including Parkinson's disease.
Between eight and nine percent of both men and women were considered regular statin users in 1994.
Over the next 12 years, five out of every 1,000 people were diagnosed with Parkinson's -- 51 who were taking statins before the diagnosis, and 593 non-users.
Ascherio's team calculated that participants taking statins were 26 percent less likely to be diagnosed with Parkinson's disease. But that could have been due to chance, the researchers reported this week in the Archives of Neurology.
In a stronger finding, younger patients -- those younger than 60 years in 1994 -- were 69 percent less likely to develop the degenerative disorder if they had been taking statins.
"It at least doesn't seem to cause Parkinson's, which was the original reason why people looked at it," said Dr. Beate Ritz, who has studied statins and Parkinson's at the University of California, Los Angeles, and wasn't involved in the new research.
"But I wouldn't yet jump to the conclusion that it would prevent it, or recommend it to people who are at risk for Parkinson's."
There are other possible explanations: for example, high cholesterol may in some way help prevent Parkinson's, Ritz told Reuters Health, and so people who would need to take statins for heart health are naturally protected.
And even if statins do prove to be protective against Parkinson's, that doesn't mean they'll do anything after a diagnosis has been made, said Dr. Benjamin Wolozin, a pharmacologist from the Boston University School of Medicine and Edith Nourse Rogers Memorial VA Medical Center.
"It probably is not the kind of thing that can modify the course of the disease if you already have Parkinson's disease," Wolozin, who wasn't tied to the new study, told Reuters Health.
The study was funded by the National Institutes of Health. One author reported a relationship with a pharmaceutical company that makes statins.
Parkinson's disease, which involves shaking and trouble with movement and coordination, is diagnosed in 50,000 to 60,000 people in the U.S. every year, according to the National Parkinson Foundation. There's no cure for the disease, but some medications can make symptoms less severe.
SOURCE: bit.ly/wKzh8B Archives of Neurology, online March 12, 2012.