Taking aspirin preventively can help reduce the risk of colon cancer in people who are at higher risk for the disease because of their lifestyle. This was found by a study led by researchers from the American health organization “Mass General Brigham”, published in the journal “JAMA Oncology”.

Colorectal cancer is the second leading cause of cancer death in the US. The US Prevention Task Force previously recommended daily low-dose aspirin to prevent cardiovascular events and colon cancer in all adults aged 50-59. However, in 2016 the recommendation was withdrawn in part due to concerns about aspirin’s increased risk of gastrointestinal bleeding.

In the current study, researchers analyzed health data from 107,655 participants with an average age of 49.4 years. They compared the rates of colon cancer in those who regularly took aspirin with those who did not. Regular aspirin use was defined as either two or more standard-dose tablets (325 mg) per week or low-dose daily intake (81 mg).

As found, participants who regularly took aspirin were more likely to develop colon cancer 1.98% per decade, while those who did not received 2.95%. Aspirin had the greatest benefit among people with the unhealthiest lifestyles. Those with the lowest healthy lifestyle scores had a 3.4% chance of developing colon cancer if they did not take aspirin regularly and a 2.12% chance if they took aspirin regularly.

In contrast, people with higher healthy lifestyle scores had a 1.5% chance of developing the disease if they took aspirin regularly and 1.6% if they did not take aspirin regularly.

It is noted that the lifestyle score was calculated based on body mass index, frequency of alcohol and cigarette use, physical activity and adherence to a high-quality diet.

The researchers clarify, however, that the study did not evaluate the potential side effects of daily aspirin use, such as bleeding. They also stress that this is an observational study, and it’s possible that there were additional factors that influenced the findings, although the study tried to control for a wide range of risk factors for colon cancer.