Taking statins may lower the risk of developing Parkinson's disease, particularly among people younger than 60, a new study suggests.
Overall, people who took cholesterol-lowering statins had a 26 percent decreased risk of developing Parkinson's disease over a 12-year period. For those under 60, the risk was reduced by 69 percent.
The results held even after the researchers took into account other factors that may heighten the risk of Parkinson's disease, such as smoking.
However, the results should be interpreted with caution, the researchers said. For starters, the calculations they made to determine whether their findings could be due to chance, instead of a real risk-reducing effect, showed that the results met this criteria, but just barely.
In addition, about 30 percent of people categorized as taking statins were likely taking another type of cholesterol-lowering drug.
In addition, statins have been found to lower blood levels of coenzyme Q, a substance that may protect against Parkinson's disease and is actually being tested as a treatment for the condition.
Because of this, and other potentially adverse effects of statins, more studies are needed to clarify the effect of these drugs on Parkinson's disease, including whether only certain types of statins have a beneficial effect.
Previous studies on whether statins reduce the risk of Parkinson's disease have had mixed results, although a 2005 study found that the drugs do not worsen the disease.
In the new study, researchers from Brigham and Women's Hospital and Harvard School of Public Health in Boston followed 38,000 men and 91,000 women from 1994 to 2006. Participants were periodically asked whether they were taking statins.
During the study period, 644 cases of Parkinson's disease occurred: 593 among the 118,031 people who did not take statins (or 0.5 percent), and 51 among the 11,035 people who did take statins (or 0.46 percent).
For those over 60, there was no link between statin use and a lower risk of Parkinson's disease.
Statins might lower the risk of Parkinson's because they reduce inflammation in the brain, the researchers said.
Among the study's limitations are that it did not take into account the drugs' potencies, doses or abilities to cross into the brain, said Dr. Fatta Nahab, an assistant professor of neurology and neuroscience at the University of Miami Miller School of Medicine, who was not involved in the study.
"Since the brain changes associated with Parkinson disease occur over years to decades, it will also be challenging to design clinical trials to observe the modest differences identified in this study," Nahab said.
The study is published in the March issue of the journal Archives of Neurology. One of the study researchers served as a consultant for Teva Pharmaceuticals, which manufactures a statin. The study was funded by the National Institutes of Health and the National Institute of Neurological Disorders and Stroke.