Researchers from Imperial College and King’s College in the United Kingdom analyzed 13 clinical trials involving more than 164,000 participants without cardiovascular disease between the ages of 53 and 74.
The researchers wanted to find out if aspirin prevented cardiovascular disease in this population and what the risk of bleeding was that required hospitalization.
The findings, published in the Journal of the American Medical Association (JAMA), suggest that although regular aspirin use will prevent cardiovascular disease in people who have never had a heart attack, it won’t reduce the odds of dying if you do have one and comes with a significant risk of bleeding.
“More people have bleeding complications from aspirin than those who are protected from a heart attack or stroke,” Dr. Salman A. Arain, associate professor of cardiovascular medicine at the McGovern Medical School at UT Health in Houston, told Healthline.
“Aspirin is an antiplatelet agent. Platelets are cell fragments that float around in the blood and stick together to form clots when activated. Activated platelets are important in forming blood clots after an injury, like a cut,” Arain explained.
“But aspirin can increase the risk of prolonged bleeding after an injury. It also makes the risk of bleeding higher in patients who may be using blood thinners for other reasons,” he said.
Aspirin also blocks cyclooxygenase. This enzyme reduces the body’s ability to produce chemicals that can cause inflammation.
The researchers analyzed data from nine different clinical trials to find that the recommended aspirin dose of 75 to 100 milligrams (mg) per day only protected against cardiovascular disease in individuals weighing less than 154 pounds.
It took a 300 mg or higher dose to effectively protect individuals weighing 154 or more pounds.
Body weight affects how our bodies use many medications.
In general, the more someone weighs, the higher a dose may be needed for a drug to work properly.
The Aspirin in Reducing Events in the Elderly (ASPREE) trial examined the preventive effects of 100 mg of aspirin daily versus a placebo in about 19,000 Australian and U.S. participants 70 years old and older who had no cardiovascular disease, dementia, or disability.
Researchers found no evidence that aspirin provided any cardiovascular benefit, although participants taking aspirin still showed a higher risk for major bleeding.
It’s not a simple question to answer.
While doctors accept that aspirin will protect people who already have a diagnosis of cardiovascular disease, they’re less clear on whether it helps those who haven’t received a diagnosis.
“If you already had a heart attack or stroke, then yes. Although the opposite is not a hard no,” Dr. Robert Segal, cardiologist and co-founder of LabFinder, told Healthline. “Depending on your lifestyle or health history, it’s best discussed with your healthcare provider.”
“They’re more effective at preventing a second or third episode,” he continued, “so all patients who have had a heart attack or embolic stroke (stroke related to a blood clot) should take a statin as long as they can tolerate it.”
However, Segal cautions that “statins shouldn’t be taken when you’re pregnant, breastfeeding, or you have an active liver disease. There are also medications that you cannot take together with statins.”
“This study reinforces the idea that aspirin should be used cautiously in patients with risk factors for coronary artery disease and stroke, and that lifestyle modification and risk factor treatment may be the safer method to prevent an event,” Arain said.
- Get regular exercise and other physical activity.
- Eat a healthy diet low in saturated fat, refined sugars, and simple carbohydrates.
- Don’t smoke, and avoid secondhand smoke.
- Maintain a healthy waistline.
- Treat and manage other risk factors, like high blood pressure or diabetes.
But while aspirin has its pros, new research suggests it does carry an increased risk of internal bleeding that requires hospitalization.