A government-backed health panel on Monday said taking a daily dose of aspirin can help prevent both cardiovascular disease and colorectal cancer, but the recommendation stoked a long-running disagreement about whether the practice carries more risks than benefits in some patients.

The announcement marked the first time the U.S. Preventive Services Task Force, an independent advisory panel of medical experts, has endorsed the combined benefits of aspirin in preventing cardiovascular problems and colorectal cancer in certain patients. Those conditions collectively kill hundreds of thousands of Americans each year.

The group on Monday recommended a daily low-dose aspirin for adults ages 50 to 69 who are at increased risk of cardiovascular disease. It also said aspirin can help reduce cancer risk if taken "for at least 10 years." The panel added that the benefits of taking aspirin can vary depending on a person's age and health, and that people should consult with a doctor before taking aspirin regularly.

[Aspirin can help prevent a second heart attack, but what about a first?]

"Taking aspirin is easy, but deciding whether or not to take aspirin for prevention is complex," Kirsten Bibbins-Domingo, vice chair of the task force and a professor of medicine at the University of California, San Francisco, said in announcing the recommendation.

While doctors widely agree that patients who have suffered heart attacks or other cardiac events can benefit from taking low-dose aspirin, they are far less united about whether people who haven't yet had such troubles should take aspirin proactively -- a practice known as "primary prevention." That's because taking an aspirin a day carries its own risks, namely bleeding in the stomach and brain.

In its recommendation Monday, the U.S. task force concluded that available evidence suggests that adults ages 50 to 69 who are at increased risk of cardiovascular disease could benefit from daily aspirin use, even if they have not had previous heart problems. That stance seems at odds with findings published last year by the Food and Drug Administration.

[Daily dose of aspirin may cut colon cancer risk -- but don't run to the drugstore just yet]

"The FDA has reviewed the available data and does not believe the evidence supports the general use of aspirin for primary prevention of a heart attack or stroke," the agency wrote in May 2014. In addition, the FDA denied a request by pharmaceutical giant Bayer to change the labeling on aspirin to allow marketing of the product for prevention of heart attacks in patients with no prior history of cardiovascular disease.

"There’s an incredible paradox here," said Steven Nissen, chairman of cardiovascular medicine at the Cleveland Clinic. "You have two different arms of the government [giving] exactly opposite advice."

Nissen said he believes existing evidence doesn't support people taking aspirin before they have any cardiovascular problems, especially given the bleeding risks.

"I personally believe that a majority of people taking aspiring are 'the worried well' -- people who believe they are at risk, but they really are not," he said. "I think in this case, the U.S. Preventive Services Task Force is wrong, and the FDA is right."

Douglas Owens, a member of the task force and a professor of medicine at Stanford University, said the group's recommendation isn't so black and white.

"It is nuanced," Owens said. "You need to make two assessments. One is, what is someone's risk of cardiovascular disease? And the second is, what is their risk of bleeding complications? ... Those assessments should be made by patients with their clinicians."

Even within age groups, the recommendations can vary. Owens noted that people ages 50 to 59 who are at risk of cardiovascular disease are likely to see more benefits from a daily low-dose aspirin than people ages 60 to 69. But even then, he said, the decision should be an individual one.

"Our conclusion was for people in these specific groups, the benefits outweigh the potential harms," Owens said. "[But] this is a decision you make with a clinician. You don’t just go to the drugstore and start [taking] aspirin by yourself."

Ranit Mishori, a professor of family medicine at Georgetown University, called the task force's new recommendation "very intriguing and even exciting," particularly regarding prevention of colon cancer, she said it likely won't change how she approaches the topic with her patients.

“While I am excited to offer this as an option to my patients," Mishori said in a statement about the new recommendation, "I will continue to emphasize and insist they adhere to other colorectal cancer prevention strategies such as maintaining a healthy diet — eating a diet rich in fruits and vegetables and low in red meat — exercising, not smoking, and to recommended colorectal screening protocols."

The task force said it will accept public comments on Monday's draft recommendation through Oct. 12.

Read more:

Provocative study raises questions about human transmission of Alzheimer's protein -- FAQ

Scientists: Why running makes you so happy

In awesome feat of engineering, paralyzed man takes steps with robotic exoskeleton

Secrets of aging may be in long-lived smokers, a 'biologically distinct' group