A woman takes an aspirin with a glass of waterShare on Pinterest
Experts said daily use of low-aspirin has some benefits, but there are also some risks. andreswd/Getty Images
  • Researchers report that older adults who take a low-dose aspirin every day have a higher risk of developing anemia.
  • Last year, a federal task force recommended that people over the age of 60 should not take aspirin to prevent cardiovascular disease.
  • Experts say there are some benefits of daily aspirin use for people under the age of 60.

Taking a low-dose aspirin every day could cause anemia, according to a new study published in Annals of Internal Medicine.

Researchers analyzed data from the ASPirin in Reducing Events in the Elderly (ASPREE) study for reach their conclusions.

For their study, the researchers randomly assigned 19,114 people 70 and older to take either a 100 mg aspirin or a placebo.

The scientists followed the participants for an average of 5 years, measuring the participants’ hemoglobin annually.

They measured ferritin levels at baseline and again three years after randomization. Ferritin is a protein inside blood cells that stores iron and releases it as your body needs it.

When compared to participants taking a placebo, the researchers reported that their findings included:

  • The risk of developing anemia by about 20% higher for those taking aspirin daily
  • There was a slight decrease in mean hemoglobin in those taking aspirin
  • There was a more significant decline in ferritin concentrations

They said the results suggest periodic monitoring for iron and ferritin levels of people taking daily aspirin.

“Overall, the study has a large number of participants, which gives it more value and credibility,” said Dr. Neal Patel, a family medicine specialist with Providence St. Joseph Hospital in California who was not involved in the study, told Medical News Today. “The fact that they did this study in two different countries also helps bolster the results.”

In April 2022, the U.S. Preventive Services Task Force recommended that adults 60 and over should not take aspirin to prevent cardiovascular disease.

For people 40 to 59, the task force said aspirin should be considered individually for people with an estimated cardiovascular risk of 10% or more.

“Aspirin works by thinning the blood, which helps to reduce the risk of plaque rupturing, which then reduces the risk of blood clotting.,” Patel explained. “Over the span of a person’s life, cholesterol and plaque can build up against the walls of the arteries in the heart and the body. Thus, blood now has less space to flow through, which can lead to increased pressure through those arteries. If the pressure rises high enough, there is a risk that the plaque can rip off the side of the artery wall, which can lead to bleeding.”

Once any type of bleeding occurs in the body, its goal is to stop the bleeding by creating a clot,” Patel added. “However, creating a clot in the artery can cut off the blood supply, leading to heart attacks and even strokes. Therefore, by thinning the blood, it is presumed that the chance of plaque rupture decreases since there is less pressure and shear force being applied against the plaque wall.”

Around 3 million people in the United States have anemia, according to the American Society of Hematology.

The condition occurs when there aren’t enough red blood cells or when these cells don’t function properly.

The American Society of Hematology lists the symptoms of anemia as follows:

“In older adults, the association between aspirin use and anemia is primarily related to the increased risk of gastrointestinal bleeding,” said Dr. David Cutler, a family medicine physician at Providence Saint John’s Health Center in California who was not involved in the study. “When there is chronic or recurrent bleeding from the gastrointestinal tract, it can lead to iron deficiency anemia, as iron is necessary for the production of hemoglobin in red blood cells. Chronic blood loss can deplete iron stores in the body, resulting in anemia over time.”

“It’s important to note that not all older adults who use aspirin will develop anemia and the risk varies depending on several factors such as the individual’s overall health, dose and duration of aspirin use, and any other underlying conditions they may have,” Cutler told Medical News Today. “There are alternative medications available that may have a lower risk of gastrointestinal bleeding, as well as protective medication to prevent bleeding when aspirin or other NSAID medication is used. The decision on which, if any, medication to use requires the knowledgeable weighing of risks and benefits as well as considering all alternatives.”

“Alternatives to aspirin would depend on the condition for which aspirin is being used,” Cutler added. “Some of the common uses of aspirin are for pain, inflammation, and preventing the clotting of blood, which can lead to heart attacks and strokes. Acetaminophen (Tylenol) is an alternative pain medication. Ibuprofen (Advil or Motrin) is an alternative NSAID anti-inflammatory. Clopidogrel (Plavix) is an antiplatelet drug that prevents clots.”

Daily aspirin use is associated with an increased risk of intracranial hemorrhage, according to a study completed in 2019. This can be life-threatening and can lead to stroke.

Xarelto and Eliquis, used to treat atrial fibrillation and blood clots, can significantly increase the risk of bleeding when taking aspirin daily.

“Other potential side effects, of course, include bleeding, abdominal pain, abdominal ulcers, dehydration, nausea, vomiting, rash/hives (if allergic reaction), bruising, increased risk of brain bleeds if a patient has a head injury, kidney and liver issues,” Patel said.

However, Patel said aspirin does have beneficial uses.

“I’d rather my patients take a low dose aspirin to prevent further cardiovascular complications rather than not take it and worry about risks of anemia,” he said. “Nowadays they have ‘enteric’ coated aspirin, which means that the pills can withstand the acid that is released from the stomach before they are fully dissolved in the small intestine. This may provide added protection against stomach/GI bleeds.”