A new study found that some common over-the-counter medications may help prevent the risk of colon cancer.

Researchers at Massachusetts General Hospital and Harvard Medical School in Boston studied 20 years of health data on more than 80,000 women. They found that regular use of aspirin and NSAIDS was associated with a reduced risk of colorectal cancer -- but only after long-term use.

"It appeared that it really required prolonged consistent use of over a decade before we saw significant benefit," researcher Dr. Andrew Chan said in a news release.

In fact, it took at least 10 years of taking a lot of pills.

"It was the highest doses of aspirin and NSAIDS that were needed to prevent colorectal cancer," said Chan. "Specifically for aspirin, it really required more than 14 standard adult aspirin tablets per week to really realize the maximal benefit."

Priscilla Groves, 56, found out she had colon cancer a year ago.

"I was getting episodes of severe pain and vomiting over and over which would last about eight, 10 hours," Groves said.

The new findings, published in Wednesday's issue of the Journal of the American Medical Association, sounded like good news to Groves, who worries about her son getting colon cancer.

"I would think it would be something that, maybe it should just be a part of everyone's regimen to do it unless you have a problem with your stomach and can't do it," Groves said.

And that is a real concern. Women who took more than 14 tablets a week for 10 years reduced their risk of colon cancer by half. But researchers found that all those tablets also caused a greater risk of bleeding in the stomach and intestines.

"It would be nice to develop a pill that people could take to prevent cancer," said Chan. "At this point, I don't think we have that. I think we have a lot of research that suggests we're getting closer to that point."

Past studies have shown negative health effects associated with long-term NSAID use, like an increased risk for high blood pressure.

Chan said regular cancer screenings are still the best way to protect yourself against colon cancer. Experts say other prevention measures include exercise and eating a high-fiber, low-fat diet.