Over-the-counter pain relievers that contain ibuprofen could lower a person's risk of developing Alzheimer's disease, according to a recent study.

Study participants who took the drug daily for five years had a 40 percent lower risk of developing Alzheimer's, doctors said.

"The longer you were on ibuprofen, the odds-ratio of developing Alzheimer's disease decreased," said Dr. Angela Scicutella, with the Long Island Jewish Medical Center in New York City.

Ibuprofen is found in such drugs as Advil and Motrin.

The study found that a second pain reliever, naproxen, also reduced the risk but not by as much.

Doctors said ibuprofen might work to lower the risk of Alzheimer's because the drug reduces inflammation. In the brain, inflammation can cause a plaque substance to build up and possibly lead to Alzheimer's.

Researchers said previous studies of ibuprofen's effect on Alzheimer's have yielded conflicting results, but the most recent study is the longest one of its kind.

Amelia Tirado said the study results are encouraging, since she already she takes ibuprofen daily for arthritis.

"That sounds pretty good for me, because I need it," Tirado said.

About 10 million baby boomers are projected to develop Alzheimer's in the coming years.

Doctors cautioned they can not recommend prescribing ibuprofen to prevent Alzheimer's.

"Certainly, we are not at a point now where we would advocate that," Scicutella said.

Researchers said they will continue to study ibuprofen as a treatment of Alzheimer's and as a means to better understand the causes of the disease.

Doctors also warn that over-use of ibuprofen has been associated with kidney disease. Consult your doctor before taking any medications.