Why You Shouldn’t Take an Aspirin Everyday, by Professor Rob Galloway
Rarely a week goes by when I don’t give at least one patient 300mg of aspirin. For people with acute chest pain, possibly having a heart attack, it can literally be life-saving. It helps make blood less sticky and breaks up clots in the arteries, allowing oxygen to get to the cardiac muscles.
Aspirin comes in low and high doses and is available to buy at most pharmacies. There’s a large 300mg dose, for the treatment of a suspected heart attack or as an anti-inflammatory and painkiller; and a 75-100mg daily dose people take to prevent heart attacks and strokes.
But as with any drug, there are risks. The unique problem with aspirin is that it is cheap and widely available, so easily self-prescribed. In fact, millions of seemingly healthy people in this country are thought to take it daily to prevent a heart attack or stroke.
For centuries, it has been used in the form of salicylic acid — derived from the bark of willow trees — as an anti-inflammatory drug. Then, in 1899, the pharma company Bayer purified it and created the drug we know as aspirin.
Initially used to treat arthritis, in the 1950s a GP in California discovered its role in preventing heart attacks and strokes, and it was quickly hailed as a wonder drug. Doctors began to recommend that anyone over the age of 55 who was worried that they were at risk of a heart attack could take the drug daily as a preventive.
Aspirin works by acting on the platelets, which play a key role in forming clots. But herein lies the problem: the way it works is also the way it can cause harm. Over the years, there has been a slew of studies reinforcing warnings of the drug’s side effects, which include internal bleeding and gastric ulcers.
Just a week ago, some news outlets reported on a study that revealed the danger of it triggering anaemia [where your body doesn’t have enough red blood cells, usually a result of bleeding] in older patients.
Published in the journal Annals of Internal Medicine, it looked at data from more than 19,000 over-65s in the U.S. and Australia who were taking daily low-dose aspirin (100mg) or a dummy tablet, over five years.
The theory was that aspirin would increase life expectancy and reduce the risks of dementia. The results showed taking aspirin made no difference — but that it did come with risks.
As we age, our risk of anaemia rises for many reasons: less iron is absorbed by our guts, bone marrow is less effective at making red blood cells, and the kidneys produce less of the hormone erythropoietin which helps with the production of red blood cells.
But the study showed the risk of anaemia was 20 per cent higher in older people taking aspirin compared with those taking the dummy tablet. When the researchers looked at the causes, they found that people taking aspirin had lower levels of iron — almost definitely caused by more bleeding in their stomachs.
Nor was it just tiny bleeds; the rate of catastrophic stomach bleeds was 50 per cent higher in those taking aspirin than those taking the dummy. So what does this mean for you and me?
A few years ago, I treated a man in his 70s. He lived a very healthy life: he was a nonsmoker, ate well and played tennis three times a week. He’d seen two of his friends die of heart attacks and had read about the benefits of taking a low-dose (75mg) aspirin daily — the dose you can buy from any pharmacy.
He came to A&E because he felt dizzy. His blood pressure was low, and just as we were trying to work out what was going on, he gave us the answer by vomiting bright red blood. We gave him six units of blood and rushed him to have an endoscopy to investigate what was going on.
The bleeding came from a stomach ulcer and was stopped. The cause was almost definitely the aspirin he was — but shouldn’t have been — taking. He survived, but he was lucky. This new study confirms that aspirin can be dangerous if taken for a significant amount of time, especially if you’re older. It might also not be suitable for doctors to recommend it as a preventive treatment, as they often do if you haven’t had a heart attack or stroke.
In 2022, the U.S. Preventive Services Task Force changed its recommendation for those over 60, advising against the use of daily aspirin to prevent a first heart attack or stroke because the benefit is outweighed by the potential risk of internal bleeding.
The advice is different if you have had a heart attack or stroke and are trying to prevent another one. The NHS also says you should only take daily low-dose aspirin if your doctor recommends it because of a high risk of heart attack or stroke.
We are also cautious when we prescribe long-term aspirin, with 2022 NHS guidance saying it should be used with caution in the elderly and those with anaemia. What about those who take aspirin because they have a specific heart rhythm problem?
My advice is to be guided by your doctor; there are new drugs that are more effective than aspirin for this. How about taking it before a flight to reduce the risk of deep vein thrombosis? The answer is an emphatic no. The risks of triggering a bleed at 35,000ft are too high. Instead, take regular walks and wear compression stockings.
Aspirin is still a drug people should have at home for emergencies because if you get severe chest pain, a 300mg dose could make a huge difference to your chance of surviving. But as a general rule, do not self-medicate — always discuss it first with your doctor.
