Approximately one in six adults in the United States has high cholesterol, a risk factor for chronic conditions like heart disease and diabetes, according to the Centers for Disease Control and Prevention. For millions of people, doctors prescribe statins, including such popular brand names as Lipitor, Zocor and Crestor, among others, to lower LDL or "bad" cholesterol.
After some anecdotal reports that statin users experienced short-term memory lapses, the U.S. Food and Drug Administration issued warnings in 2012 that these medications may increase risk of memory loss. But now a new study suggests those warnings may be unfounded.
Researchers at Rutgers and the University of Pennsylvania looked at 482,542 new statin users and compared them to an equal number of people who were not taking any cholesterol-lowering drugs. Additionally, new statin users were also compared to another 26,484 people taking nonstatin lipid-lowering drugs (LLDs).
The results, published today in The Journal of the American Medical Association-Internal Medicine, showed that more patients taking statins did indeed report short-term memory loss in the 30-day period after first taking the drug when compared to people not taking any cholesterol-lowering drugs. However, the same was true for patients taking nonstatin LLDs.
"These are drugs that work by completely different mechanisms, and it's not biologically plausible that they'd have the same effects," lead study author Dr. Brian Strom, chancellor of Rutgers Biomedical and Health Sciences, told CBS News.
Strom's conclusion then was that statins do not cause memory loss, but people are more likely to recognize health problems when they start a new drug -- a so-called "detection bias."
"People have memory problems all the time," he said. "You lose your keys. You forget somebody's name. When you get put on a new drug you're more likely to blame it on the drug you just took."
When starting a new drug, people are also more likely to visit the doctor more frequently, which can add to detection bias. "If you go to the doctor more, you're going to be more likely to report medical issues of any kind," said Dr. James Underberg, clinical assistant professor of medicine at New York University Medical School. "You could take a group of people who go to the doctor and find they report more instances of fever or a cold or almost anything." Underberg was not involved in the study.
Furthermore, Strom pointed out that studies have consistently shown statin use is associated with improved long-term memory. "The theory behind that is that statins prevent heart disease, which occurs in the brain, as well," he said. "So by decreasing mini strokes and hardening of the arteries in the brain, it would improve long-term memory, and there's good data showing that."
Both doctors emphasized that although, like all prescription drugs, both statins and LLDs may have side effects, people should not stop taking these medications without consulting their doctors.
"Statins are one of the most effective methods of preventing heart disease," Strom said. "They are remarkably safe and people should not be reluctant to use them because they fear of possible short-term memory loss."