Is it still a good idea to take aspirin to prevent heart disease? Here’s what the evidence says

You might have heard that taking a daily low-dose aspirin can reduce your risk of developing heart disease. But, unless you have been told to take aspirin by your doctor, recent news should make you think again, because, for many, the risks outweigh the benefits.

According to a new study, older adults in the US continue to take aspirin despite growing evidence questioning its benefits for those without a history of cardiovascular disease.

But what is the approach in the UK? Will you be advised to take a daily low-dose aspirin if you’ve never had heart issues?

For years, aspirin has been considered a simple, inexpensive way to reduce the risk of heart attacks and strokes. The idea is straightforward: aspirin thins the blood, helping to prevent the formation of clots that can block arteries and cause heart attacks or strokes. However, recent studies have raised concerns about the safety and effectiveness of this approach, especially for those without a history of heart disease.

In the UK, guidelines have evolved to reflect this new understanding. The National Institute for Health and Care Excellence (Nice), which advises the NHS in England and Wales, now recommends against the routine use of low-dose aspirin for preventing heart disease in people who have not had previous heart problems, such as a heart attack, as the risk of a bleed is too great to warrant it.

UK changed advice on aspirin in 2009

Nice changed its guidance on the use of aspirin for preventing an initial heart attack or stroke in 2009. The US Preventive Services Task Force, which issues guidance in the US, updated its recommendation on aspirin only in 2022.

The shift in advice stems from comprehensive research. For instance, a study published in the Journal of the American Medical Association found that in healthy older adults, aspirin did not significantly reduce the incidence of heart attack or stroke. However, it did increase the risk of life-threatening haemorrhage. Another large study in The Lancet corroborated these findings, emphasising the delicate balance between benefits and harms.

However, the chance that someone who has already had a heart attack or stroke will have another one is generally high enough to justify the risks associated with aspirin. This is called “secondary prevention”, and Nice still recommends using aspirin in these cases. Yet, even here there is evidence for more caution, with a UK study reporting in 2017 that people aged 75 and older more often experience bleeding while taking aspirin for secondary prevention.

While aspirin has been a cornerstone of heart disease prevention for decades, the emergence of new information feeds a constant cycle or revaluation and adaptation. It is down to health authorities to respond to new data and change guidelines, and to patients and doctors to adhere to these.

We now know that, for some, the risks associated with daily low-dose aspirin use may outweigh the potential benefits. If you’re taking a daily low-dose aspirin or considering it, speak to your doctor.

It’s important to talk to your doctor before starting or stopping any medication. Your doctor can help you understand your risk factors for heart disease and determine the best strategy for prevention.

Lifestyle changes, such as maintaining a healthy diet, exercising regularly and managing blood pressure and cholesterol levels, remain crucial for preventing heart disease.

Alex Bye does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.