Experts say people should balance the benefits of daily aspirin use with an increased risk of bleeding. CC BY-SA 3.0
By Healthline | April 19, 2020
- A new study found further evidence for the link between taking aspirin regularly and a reduced risk of colon cancer and other digestive tract cancers.
- Experts, however, caution that those potential benefits need to be weighed against the potential increased risk of bleeding.
- Experts say people should use medical guidelines for who might benefit from taking aspirin in deciding whether to take aspirin daily.
There is a new angle in the debate over the health benefits and risks involving daily use of aspirin.
This one has to do with the potential reduction in colon cancer risk.
A new study summarized past findings of the association between regular aspirin use and a reduction in the risk of colon cancer and other digestive tract cancers.
Researchers concluded that aspirin had been associated with a 22 to 39 percent reduction in the risk of these types of cancers.
Those findings lend further support for the link between regular aspirin use and reduced risk of those cancers.
The research also raises a question, though.
In recent years, there have been increasing warnings that the potential reduction in heart disease risk from taking aspirin regularly may not be worth the potential increased risk of bleeding.
So when and for whom should this risk outweigh the potential benefits of reduced cancer risk?
The study by the numbers
The new paper reviewed 113 studies, including studies on colon cancer, stomach cancer, pancreatic cancer, and cancers of the head, neck, esophagus, liver, gallbladder, and bile ducts.
The researchers, based in Italy, found an aspirin dose between 75 and 100 milligrams a day reduced the risk of colon cancer by 10 percent. A 325 mg per day dose reduced the risk by 35 percent.
This means the benefits of aspirin increased with higher dosage.
The study also notes that the benefits increased the longer people took the aspirin.
Who should take aspirin?
But more and longer isn’t necessarily better for everyone.
After years of recommendations that daily aspirin could help prevent heart attacks and stroke in people with a higher risk for those cardiovascular issues, research in 2018 and 2019 began to change that opinion.
That research essentially found that while aspirin did provide a reduction in heart disease risk, more people suffered bleeding complications, including in the gastrointestinal tract, due to aspirin than avoided a heart attack or stroke.
The same balancing act between potential benefits and risk needs to be assessed when it comes to cancer and aspirin, experts said.
Eric J. Jacobs, PhD, senior scientific director of epidemiology research at the American Cancer Society, said that results of the new study lined up with the findings of randomized trials, which look at more carefully selected participants in more defined settings than a summary review.
“Both indicate that regular aspirin use modestly lowers risk of colorectal cancer, a point which has been well known for many years,” Jacobs told Healthline.
But he noted that “decisions about whether or not a particular person should use aspirin must carefully balance potential benefits, including lower risk of heart attacks and colorectal cancer, against potential harms, including serious gastrointestinal bleeding.”
Aspirin is recommended for certain people with high risk of heart disease or certain cancers.
But a study last year found that nearly a quarter of adults may be taking aspirin daily without a healthcare provider recommendation.
That goes against what the experts recommend.
The American Heart Association and American College of Cardiology guidelines say that adults older than 70 who haven’t had a heart attack as well as people who have a higher bleeding risk shouldn’t take aspirin.
Assessing the risk
Jacobs said the American Cancer Society hasn’t developed guidelines itself to balance the benefits and risks, but he pointed to guidelines from the U.S. Preventive Services Task Force (USPSTF).
To reduce the risk of heart disease and colon cancer, those guidelines recommend daily low doses of aspirin for adults 50 to 59 who have at least a 10 percent risk of a heart attack or stroke within the next 10 years and who aren’t at an increased risk for bleeding.
To determine whether someone is at a higher risk, Jacobs noted that a healthcare provider can evaluate the person’s medical history or use an online risk calculator.
A calculator is available from the American Heart Association and American College of Cardiology.
The USPSTF guidelines state that the cancer-reduction benefits of taking aspirin don’t show up until someone has taken the medication for 5 to 10 years.
Because of that, people older than 60 are less likely to see the benefits if they haven’t already started taken aspirin.
The risk of gastrointestinal bleeding increases with age, the guidelines note.
Other ways to reduce risk
Aspirin isn’t the only tool out there.
“Aspirin use is not the only way or the best way to lower risk of colorectal cancer,” said Jacobs.
While you can’t do anything about the fact that risk increases with age, there are other risk factors that may be more within your control.
Those include avoiding being overweight, smoking, heavy drinking, a sedentary lifestyle, or a diet high in red meat or processed foods.
And after a certain age — 45 for most people, according to American Cancer Society guidelines — regular screenings such as colonoscopies can help reduce the risks.
Like most parts of our lives currently, however, COVID-19 has the last say on even colon cancer screenings, for now.
“Because of the current COVID-19 pandemic, going to a healthcare facility for routine cancer screening is not recommended at this time,” Jacobs noted.
“However, it is important to remember to get back on track and reschedule testing for colorectal cancer when it is safe to do so and medical facilities are able to begin testing again,” he added.