Previous studies have often linked long-term aspirin use to harmful side effects, such as internal bleeding. But according to a new study published in the Annals of Oncology, the benefits of long-term aspirin use outweigh the risks, particularly in significantly reducing the risk of cancers of the digestive tract, including stomach, intestines and esophagus. Aspirin, chemically known as acetylsalicylic acid, is commonly used to reduce minor pain, relieve inflammation and reduce fever. The drug can have an antiplatelet effect when taken at low doses over a long period of time in people at high risk for heart disease and stroke. There has been controversy surrounding the benefits of long-term aspirin use. Previous studies have shown that the drug can reduce the risk of ovarian cancer and improve survival in colon cancer, yet other studies have found that it can increase the risk of age-related macular degeneration. In this study, Prof. Cuzick and colleagues decided to determine whether the benefits of continuous long-term aspirin use would outweigh the risks. Daily aspirin is important for reducing cancer risk The researchers analyzed all available studies addressing the benefits and risks of aspirin. They estimated that individuals aged 50-65 years taking 75-100 mg of aspirin daily for 5-10 years could reduce the incidence of intestinal cancer by 35% and mortality by 40%, and stomach and esophageal cancer by 30% and mortality by 35-50%. In summary, researchers estimate that daily aspirin use for 5-10 years can reduce the incidence of cancer, stroke and heart disease by 9% in men and 7% in women. The probability of death from all diseases was estimated to decrease by 4 percent when taken for more than 20 years. No benefit was found for individuals who took the drug for less than 3 years. But the researchers emphasized that continued use of aspirin increases the risk of gastrointestinal bleeding. They found that individuals aged 60 years who took aspirin daily for 10 years could increase the risk of gastrointestinal bleeding by 1.4 percent, or from 2.2 percent to 3.6 percent. However, this could only be life-threatening for about 5 percent of the population. Prof. Cuzick. emphasized that “the risk of bleeding depends on a number of known factors, which people should know before starting aspirin. One should consult with a doctor before starting the drug.” In addition, they found that long-term aspirin use increased the risk of peptic ulcers by 30 to 60 percent. But despite these side effects, the researchers believe long-term aspirin use is extremely important for cancer prevention. With serious side effects in mind, besides quitting smoking and losing weight, taking aspirin daily may be the most important thing we can do to prevent cancer, and the easier thing to achieve. Researchers also say further studies are needed to discover those most likely to benefit from long-term aspirin use and those at risk for gastrointestinal bleeding.