Aspirin - Kill or cure?

For a drug that has been around for hundreds of years, and which most of us have in our bathroom cabinet, aspirin has provoked a remarkably regular flow of news headlines over recent years. One day it's the panacea to all our ills; the next it can do more harm than good. A study in 2013 of 77,000 people suggests that taking a regular low dose (75-300mg a day) of aspirin could cut your risk of cancer by 25% after 3 years. It could cut your risk of dying of cancer by 15% within 5 years, and possibly by as much as 37% in the longer term. Yet within weeks, another study looking at over 100,000 people suggested that the increased risk of bleeding on aspirin outweighed any possible benefit for the general population. 

So is there any way to tease out the facts behind the headlines and find a one-size-fits-all answer to the question many of us ask every day - should I take regular aspirin? The answer, sadly, is no. That's because we are all different. Like all medicines, taking aspirin carries risks as well as benefits. The most common side effect of aspirin is bleeding from the gut, which can be fatal. The longer you take it for and the greater your risk of bleeding, the greater the risk. But the higher your risk of heart disease (which it protects against) the greater the benefit. It's all a question of weighing up the pros and cons for your personal circumstances.

Questions on aspirin

How much? Most studies suggest that even if your doctor does recommend aspirin for you, taking 75mg a day (1/4 of a 'standard' aspirin painkilling tablet) is likely to help just as much as 300mg a day, and will carry a lower risk of bleeding.

Heart attack sufferers: If you've suffered a heart attack, the advice remains clear - keep taking the tablets unless your doctor advises you definitely shouldn't.

People with type 2 diabetes: Although people with type 2 diabetes are at greatly increased risk of heart attack, aspirin doesn't seem to offer the same protection it does to people who've had a heart attack. Since 2009, doctors have stopped routinely advising people with type 2 diabetes to take aspirin - speak to your doctor about your particular risks and benefits.

People with: Remarkably, research suggests regular aspirin may cut the chance of existing cancers spreading. Speak to your consultant.

People with a family history of bowel cancer: Your risk of bowel cancer may be higher if it runs in your family. Your risks of bleeding with aspirin are the same as everyone else's, but the benefit you get may be greater. Previous studies suggest you need to take it for at least 10 years to get significant benefit.

People with (AF): this common abnormal heart rhythm increases your risk of stroke by at least 500%, and this risk can be cut by a very small amount by taking aspirin However, aspirin isn't nearly as effective as a blood-thinning agent called , or newer alternatives called the 'Direct oral anticoagulants' - dabigatran, apixaban, edoxaban and rivaroxaban. What's more, the risks of bleeding with aspirin are similar to those with the more effective medicines. That's why national and international guidelines have basically stopped recommending aspirin as stroke protection if you have AF. If you are taking aspirin for AF, see your doctor about changing to a (much) more effective option.

People at high risk of side effects: If you've had a history of severe indigestion or a past, you almost certainly shouldn't take regular aspirin. You should certainly check with your doctor before you start. About 1 in 50 people with asthma also gets a worsening of their wheezing if they take aspirin.

What if I don't have any of these conditions? Previously UK guidance recommended that all over 50s should consider a daily 75mg dose of aspirin to cut their risk of heart disease. Subsequent research has suggested it may do more harm than good because of the risk of bleeding. That means it's no longer routinely recommended to prevent heart attacks. The research suggesting aspirin protects against cancer may mean it will be recommended for more people, but there are no national guidelines yet.

What age should I start and stop?

People in recent studies seemed to get protection against cancer by starting to take aspirin in their late 40s or 50s and continuing for at least a decade. By the time you reach your 70s, your risk of bleeding on aspirin increases significantly, so the risk-benefit ratio may shift again.

Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. Patient Platform Limited has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.