Dec. 22, 2015 -- It’s cheap, easy to find, and, according to some, a miracle drug.
But should you pop an aspirin every day to stay healthy?
More and more research suggests that this medicine protects against heart attacks, strokes, a variety of cancers, and even preterm birth and preeclampsia, a condition in pregnancy marked by high blood pressure and damage to organs such as the kidneys.
And most recently, a study found that salicylic acid, the active ingredient in aspirin, blocks a protein that can enter brain cells and trigger the process that leads to their death, as seen in diseases like Alzheimer’s and Parkinson’s.
But it's too soon to add protection against such brain diseases to the “pros” column when considering whether to take aspirin, says Daniel Klessig, PhD, a researcher on the new study and a professor at the Boyce Thompson Institute and Cornell University.
“While the results from our study are exciting and provide great promise as a possible treatment for neurodegenerative diseases, they will need to be followed by much more comprehensive studies, including mouse model work and human clinical studies,” Klessig says. Besides, he says, research likely will lead to compounds derived from salicylic acid that will be more effective and safer than aspirin.
That question of safety has always been at the center of the aspirin debate, even for heart disease. Aspirin’s most worrisome quality is that it can cause bleeding in the upper digestive tract, namely the stomach, and in the brain. Age increases the risk, as does having a history of bleeding.
“It’s important to discuss the risks and benefits of aspirin therapy with a physician,” says Deepak Bhatt, MD, MPH, executive director of interventional cardiovascular programs at the Brigham and Women’s Hospital.
An Aspirin Two-fer?
The U.S. Preventive Services Task Force, an independent panel of health care professionals, added a twist to the debate about whether healthy people should take aspirin. In September, it posted its draft of new guidelines about the drug's use by people 50 and older.
The guidelines are the first from a major organization to recommend aspirin to protect against cancer, in this case colorectal cancer, as well as heart disease. They're only for people ages 50-69 who have a 10% or higher risk of heart attacks and strokes over a 10-year period, and are not at an increased risk for bleeding. But the task force isn’t recommending that anyone take aspirin solely to lower the risk of colorectal cancer.
“For the patients who are taking aspirin or are thinking about taking aspirin for the purpose of cardiovascular disease prevention, it’s very easy to tell them that an additional benefit they may gain is protection against colorectal cancer,” says Andrew Chan, MD, MPH, a gastroenterologist at Massachusetts General Hospital. “I think we are starting to think more seriously about aspirin to prevent cancer.”
Klessig published a study online first in June that found that salicylic acid also blocks a protein that triggers inflammation linked to certain cancers, including colorectal cancer and mesothelioma, a rare, serious cancer usually related to inhaling asbestos.
People with no history of heart disease are at the center of the debate about the wisdom of taking aspirin to stay healthy, which is called primary prevention. While research has established that taking the drug can reduce the risk of anotherheart attack or stroke in people who’ve already had one, which is called secondary prevention, evidence that it’s worth taking to protect against a first heart attack or stroke is less clear.
For that reason, the FDA in May 2014 denied a request from Bayer for permission to add prevention of a first heart attack to the list of uses on aspirin’s label. The agency cited “insufficient data” to support such a move.
Professional groups are divided on the use of aspirin for primary prevention. The Canadian Cardiovascular Society doesn’t recommend it. Neither does the European Society of Cardiology. The American Heart Association and the preventive services task force do recommend it, but only if the potential benefits outweigh the risks.
“The potential harms (from aspirin) are actually higher than for other therapies” that protect against cardiovascular disease, such as cholesterol-lowering statin drugs, says Salim Virani, MD, PhD, a cardiologist at the Baylor College of Medicine.
Virani co-wrote a study published in January suggesting that more than 10% of U.S. patients taking aspirin for primary prevention don’t have a high enough risk of heart disease to warrant it.
People are smoking less and using statins more since the studies supporting aspirin for prevention of heart disease were done, Bhatt says. Newer, ongoing studies, which plan to enroll a total of more than 50,000 people, will help determine whether aspirin has any additional benefit on top of quitting smoking and taking statins, he says.
While research suggests people have to take aspirin for at least 5 years, if not 10, for primary prevention of heart disease and colorectal cancer, pregnant women stand to benefit from taking it for only 5 months or so, a recent study suggests.
Taking a daily baby (of course) aspirin from before the 16th week of pregnancy onward is a safe, cost-effective way to reduce the risk of preterm delivery and preeclampsia, the study concluded. Researchers used mathematical modeling to compare having all pregnant women take aspirin to the more conservative approaches recommended by the American College of Obstetricians and Gynecologists (ACOG) and the preventive services task force. Under ACOG’s guidelines, only about 1 in every 300 pregnant women is a candidate for aspirin, while the task force recommends it for about 1 in 4.
Both the task force approach and recommending aspirin to all pregnant women would lessen complications, save lives, and lower health-care costs far more than the ACOG approach, the researchers write.
“I think many of us, particularly maternal-fetal medicine specialists, are moving in the direction of broader aspirin use,” says researcher Erika Werner, MD, a maternal-fetal medicine specialist at Women & Infants Hospital of Rhode Island. No other treatment helps prevent preeclampsia, and pregnant women are generally young enough that they don’t have to worry about bleeding risks from relatively short-term use of aspirin, Werner says.
“Any patient who’s obese and over 35 should probably be taking aspirin or at least have the discussion with her doctor about the pros and cons of aspirin,” Werner says. “Almost all of the patients I’ve had that conversation with have come back and said, ‘I’m taking baby aspirin now.’”