Aspirin may help reduce the risk of colon cancer, a new study suggests, when taken in large doses over long periods of time.  Researchers studied more than 47,000 men for 18 years. After adjusting for age, smoking, diet, physical activity and other risk factors, they found that men who took more than two standard 325 mg aspirins a week reduced their risk for colon cancer by about 21 percent compared with those who took less. Men who took 6 to 14 a week reduced their risk by 28 percent, and those who took more than 14 pills a week had a 70 percent decreased risk.

The longer the men took aspirin, the more they reduced risk, but taking it for less than five years, or taking the equivalent of less than one and a half pills a week, conferred no advantage. Other non-steroidal anti-inflammatory medicines like ibuprofen (Motrin) and naproxen (Aleve) gave similar protections, but not acetaminophen (Tylenol).  {However, all but aspirin increase myocardial infraction, 50% or more when taken long-term--jk. At http://healthfully.org/aspirin/id17.html.  The mechanism is aspirin mediated apoptosis, at http://healthfully.org/aspirin/id19.html.) 

“The results provide additional proof that a simple drug like aspirin can help prevent colon cancer,” said Dr. Andrew T. Chan, the study’s lead author and an assistant professor of medicine at Harvard. Still, he said, “I wouldn’t recommend it to all patients, because of the side effects,” which can range from upset stomach to gastrointestinal bleeding.

The study, in the January issue of Gastroenterology, was not randomized, but a link between aspirin use and a drop in cancer recurrence had been established in other randomized trials.