Many seniors are putting their own lives at risk when they take a combination of drugs and supplements, a new study found.

In this study conducted at the University of Illinois at Chicago, the researchers set out to examine how current trends in medicine and dietary supplements are affecting the health of older adults. The researchers analyzed data of more than 2,000 participants between the ages of 62 and 85. The participants were interviewed in 2005-2006 and 2010-2011.

The researchers found that from 2005 to 2011, the number of seniors who were taking drug combinations, which included prescription medications, over-the-counter (OTC) drugs and dietary supplements that could have led to potentially dangerous health situations, nearly doubled from 8.4 percent to 15.1 percent.

This increase was most likely due to the fact that changes in insurance allowed for polypharmacy, which is the use of four or more prescription medications, a practice that is more common in older adults. The percentage of adults who had at least five prescription medications increased from 30.6 percent to 35.8 percent.

The researchers also noted that the availability of generic versions of certain drugs could have also increased access. For example, when they looked at the drug simvastatin (Zocor) specifically, they found that the percentage of older adults who were on it increased from 10.3 percent to 22.5 percent. The drug, which treats high cholesterol, was made available in its generic form in 2006.

Use of dietary supplements, particularly omega-3 fish oils, has also increased during the study's time frame. The researchers were not sure why older adults were taking more supplements since studies have yet to find strong evidence that these supplements have clinical benefits.

OTC drug use was the only statistic that declined. From 2005 to 2011, the number of older adults who used these drugs went from 44.4 percent to 37.9 percent.

Lead researcher Dima Mazen Qato cautioned that based on this study's findings, doctors should be more aware of what kind of drugs their older patients are taking. Even though certain drugs might be good for one's health, combining them with other drugs could potentially negate those effects or cause a dangerous one.

"Many older patients seeking to improve their cardiovascular health are also regularly using interacting drug combinations that may worsen cardiovascular risk," Qato explained. "For example, the use of clopidogrel in combination with the proton-pump inhibitor omeprazole, aspirin, or naproxen - all over-the-counter medications - is associated with an increased risk of heart attacks, bleeding complications, or death. However, about 1.8 percent - or 1 million - older adults regularly use clopidogrel in interacting combinations."

The investigators stated that although they did not assess risk of death from these drug combinations, policy makers should work to improve safety measures for people who have to talk multiple drugs.

"Improving safety with the use of multiple medications has the potential to reduce preventable adverse drug events associated with medications commonly used among older adults," the authors wrote.

The study was published in JAMA Internal Medicine.