This Much Regular Aspirin Could Reduce Your Risk of Colorectal Cancer, Study Finds

Key TakeawaysA recent study found regular use of aspirin can lower the risk of colorectal cancer, especially for individuals with unhealthy lifestyles.While more research is needed to understand how regular aspirin use might reduce colorectal cancer risk, experts say that aspirin may block pro-inflammatory signals that contribute to cancer development.Patients should consult their healthcare provider before taking aspirin to weigh its potential benefits and risks carefully.

Key Takeaways

A recent study found regular use of aspirin can lower the risk of colorectal cancer, especially for individuals with unhealthy lifestyles.While more research is needed to understand how regular aspirin use might reduce colorectal cancer risk, experts say that aspirin may block pro-inflammatory signals that contribute to cancer development.Patients should consult their healthcare provider before taking aspirin to weigh its potential benefits and risks carefully.

Aspirin is often used as a go-to remedy for relieving headaches, reducing fevers, and easing menstrual cramps. Now, research shows that regular aspirin use might also lower the risk of colorectal cancer.

The study, published in the journalJAMA Oncology, showed that people with the least healthy lifestyles benefited the most from taking aspirin. This includes individuals who indicated they had a higher alcohol intake, little to no physical activity, poor diet quality, higher body mass index (BMI), and smoked or previously smoked.

These factors were each already known to increase a person’s risk of colorectal cancer, first study authorDaniel Sikavi, MD, a gastroenterology fellow at Massachusetts General Hospital and Clinical Fellow in Medicine at Harvard Medical School, told Verywell in an email.

“Our results show that aspirin can proportionally lower this markedly elevated risk. In contrast, those with a healthier lifestyle had a lower baseline risk of colorectal cancer, and therefore, their benefit from aspirin was still evident but less pronounced,” Sikavi said.

Here’s what else you need to know about the study and why regular aspirin use could lower colorectal cancer risk, according to experts.

Why ‘Unhealthy’ People Reap the Most Aspirin Benefits

A Note on Gender and Sex TerminologyVerywell Health acknowledges thatsex and genderare related concepts, but they are not the same. To reflect our sources accurately, this article uses terms like “female,” “male,” “woman,” and “man” as the sources use them.

A Note on Gender and Sex Terminology

Verywell Health acknowledges thatsex and genderare related concepts, but they are not the same. To reflect our sources accurately, this article uses terms like “female,” “male,” “woman,” and “man” as the sources use them.

The team found that among those with lifestyle factors linked to higher colorectal cancer risk—such as regular tobacco and alcohol use, a poor diet, lack of exercise, and a higher BMI—those who took aspirin regularly had an 18% lower risk of developing colorectal cancer.

The researchers also found participants with the least healthy lifestyles had a 3.4% chance of developing colorectal cancer over 10 years if they didn’t take aspirin regularly, compared to a 2.1% chance if they did. “This corresponded to a 1.3% lower absolute risk of cancer associated with taking aspirin,” Sikavi said.

On the other hand, those with the healthiest lifestyles had a 1.6% chance of colorectal cancer with regular aspirin use and a 1.5% chance without it, leading to a 0.1% lower absolute risk of cancer over 10 years, Sikavi said.

“This means that in the least healthy group, treating 78 patients with aspirin would prevent one case of colorectal cancer over a 10-year period, while it would take treating 909 patients to prevent one case for the healthiest group,” said Sikavi.

It’s important to note that people with healthier lifestyles already had a lower chance of getting colorectal cancer to begin with,Andrew Chan, MD, MPH,a gastroenterologist at Massachusetts General Hospital and professor in the Department of Immunology and Infectious Diseases, told Verywell in an email. Because of this, while taking aspirin did still help reduce their cancer risk, the effect wasn’t as strong as it was for people with less healthy lifestyles.

“We can go beyond one-size-fits-all strategies for cancer prevention. We know that there are very specific lifestyle factors that put people at risk for colorectal cancer,” Chan said. “And I think this provides some proof of principle that there is an option for us to help reverse some of those lifestyle risk factors. And that’s through an inexpensive and easy-to-use and well-established drug like aspirin.”

Comparing Acetaminophen and Aspirin

Why Might Regular Aspirin Use Lower Colorectal Cancer Risk?

While this study cannot determine why regular aspirin use can be effective in reducing cancer risk, it may be due to aspirin’s well-known anti-inflammatory properties,Wael Harb, MD, a board-certified hematologist and medical oncologist at MemorialCare Cancer Institute at Orange Coast and Saddleback Medical Centers in Orange County, CA, told Verywell.

Aspirin has anti-inflammatory effects because it blocks an enzyme called cyclooxygenase (COX), which is involved in inflammation and cell growth, Harb said. “By reducing the production of proinflammatory molecules called prostaglandins, aspirin may help lower the risk of cancers, including colorectal cancer, since chronic inflammation is a known risk factor.”

Aspirin also appears to block signaling pathways within cells, which can prevent them from growing and spreading, such as tumor cells, Sikavi said.

It’s important to note while these are some possible ways aspirin might work, more research is needed to fully understand these mechanisms, Harb said.

Cancer can develop differently in each person. For instance, Harb said some cases of colorectal cancer may be related to environmental factors, while others might involve a weakened immune system.

For people with less healthy lifestyles, their immune system and metabolism might not be as strong, making them more vulnerable to cancer, said Harb.“This increased risk could explain why aspirin seems to be more beneficial for them compared to others. Instead of recommending aspirin for everyone [with cancer], we should target its use to those who are likely to gain the most from it.”

USPSTF: Adults 60+ Should Not Start Taking Daily Aspirin

Are the Findings Enough to Change Current Guidelines?

The U.S. Preventive Services Task Force (USPSTF) previously recommended that most adults aged 50 to 59 take a low-dose daily aspirin to prevent colorectal cancer. However, in 2016, they withdrew this recommendation due to concerns about an increased risk of gastrointestinal bleeding and the need for more research.

The USPSTF requires strong evidence from multiple, well-conducted studies before making any changes to guidelines, Harb said. Although this recent study is large and presents compelling results regarding the reduction of colorectal cancer risk, he said it’s likely that the USPSTF will want to see additional evidence before revising their recommendations.

“While the study’s findings are promising, it’s important for the USPSTF to carefully review the evidence and consider specific subsets of patients to see if there’s a subset of people that might benefit from aspirin use, as highlighted in the study.”

What Are the Risks of Using Aspirin?

The risks of using aspirin can vary from person to person, so it’s important to assess an individual’s likelihood of experiencing side effects before starting regular use, Harb said. “If the risks outweigh the benefits, it’s best to avoid taking aspirin.”

The most common side effect of regular aspirin use is bleeding, especially within the gastrointestinal tract, Harb said. This can occur because aspirin can cause inflammation in the stomach lining or lead to peptic ulcers.

Sikavi added that people who are taking blood thinners such as Coumadin (warfarin), Eliquis (apixaban), and Xarelto (rivaroxaban) are more likely to have bleeding, as well as people living with bleeding disorders.

Other side effects of aspirin use include nausea, vomiting, stomach pain, and heartburn. More serious side effects include hives, rash, fast heartbeat, cold, clammy skin, or loss of hearing.

Study: Benefits of Daily Aspirin May Not Outweigh the Risks

Should You Use Aspirin Regularly to Prevent Colorectal Cancer?

Despite the study’s findings, Harb said that it’s still too early to recommend that people start taking aspirin regularly to prevent colorectal cancer.

Instead, he suggests focusing on regular screening, which is one of the most important approaches to preventing colorectal cancer. “We have effective tools like colonoscopies that can detect colon cancer at early stages, making it highly treatable,” Harb said.

Additionally, there areless invasive tests, such as stool tests that detect blood or DNA changes linked to colorectal cancer, and even anFDA-approved blood testfor early detection, said Harb.

Before starting or stopping aspirin or any other medication, it’s important to consult with your healthcare provider, Harb said. They can help you weigh the risks and benefits and guide you in making the best decision for your health.

What This Means For YouBefore starting any new medication, including over-the-counter options like aspirin, experts recommend talking with your healthcare provider first. It’s also a good idea to discuss strategies for preventing colorectal cancer with your provider.

What This Means For You

Before starting any new medication, including over-the-counter options like aspirin, experts recommend talking with your healthcare provider first. It’s also a good idea to discuss strategies for preventing colorectal cancer with your provider.

4 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Sikavi DR, Wang K, Ma W, et al.Aspirin use and incidence of colorectal cancer according to lifestyle risk.JAMA Oncol.Published online August 1, 2024. doi:10.1001/jamaoncol.2024.2503AIM At Melanoma Foundation.Weakened immune system.U.S. Preventive Services Task Force.Aspirin use to prevent cardiovascular disease: preventive medication.National Library of Medicine: MedlinePlus.Aspirin.

4 Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Sikavi DR, Wang K, Ma W, et al.Aspirin use and incidence of colorectal cancer according to lifestyle risk.JAMA Oncol.Published online August 1, 2024. doi:10.1001/jamaoncol.2024.2503AIM At Melanoma Foundation.Weakened immune system.U.S. Preventive Services Task Force.Aspirin use to prevent cardiovascular disease: preventive medication.National Library of Medicine: MedlinePlus.Aspirin.

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

Sikavi DR, Wang K, Ma W, et al.Aspirin use and incidence of colorectal cancer according to lifestyle risk.JAMA Oncol.Published online August 1, 2024. doi:10.1001/jamaoncol.2024.2503AIM At Melanoma Foundation.Weakened immune system.U.S. Preventive Services Task Force.Aspirin use to prevent cardiovascular disease: preventive medication.National Library of Medicine: MedlinePlus.Aspirin.

Sikavi DR, Wang K, Ma W, et al.Aspirin use and incidence of colorectal cancer according to lifestyle risk.JAMA Oncol.Published online August 1, 2024. doi:10.1001/jamaoncol.2024.2503

AIM At Melanoma Foundation.Weakened immune system.

U.S. Preventive Services Task Force.Aspirin use to prevent cardiovascular disease: preventive medication.

National Library of Medicine: MedlinePlus.Aspirin.

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