For a pill that costs just pennies per dose, aspirin can do an awful lot. It prevents heart attack and stroke in people with a history of cardiovascular events. It’s recommended for angina and heart attack patients as soon as they arrive at the hospital. It may lower risk of colon and other types of cancer. And, yes, it’s good for the occasional aches and pains, too.
So it’s no wonder that in recent years, some health experts have been wondering whether everyone, whether or not they have heart troubles or headaches, should be taking low-dose aspirin as a preventive for some chronic illnesses. But the evidence doesn’t seem to support that idea, including a new review of nine clinical trials, published in the Archives of Internal Medicine. The study shows that aspirin does reduce the risk of heart attack in middle-aged adults without known heart disease, but that those benefits are “modest,” according to the study authors. The review showed that aspirin appeared to confer no protection against stroke or fatal heart attack, and the limited benefits against non-fatal heart attack were offset by relatively rare but dangerous side effects.
Aspirin helps to prevent heart attacks by preventing blood clots from forming, which can impede blood flow to the heart and brain. Recent studies also hint that it works to lower inflammation, which not only inhibits clot formation, but may protect unstable plaques in heart vessels from rupturing. Unfortunately, however, limited blood clotting can be dangerous as well. People who take a regular aspirin appear to be at increased risk of internal bleeding, which in some cases can be life-threatening.
The new study in Archives is the largest of its kind to date. It includes nine clinical trials which together involve more than 100,000 study participants from a number of developed countries. In each of the nine trials, participants were randomly assigned either to take a daily aspirin or to take a placebo. On average, the aspirin-takers took their pills for six years.
The analysis finds that, on average among the trials, one cardiovascular disease event was averted for every 120 people who took a daily aspirin. But there was one “nontrivial bleeding event” for every 73 people on the daily aspirin regimen. And the researchers found no significant difference in mortality between the aspirin groups and the placebo groups.
Because more people were likely to experience a bleeding episode than be protected from a heart-related event, the study authors conclude: “routine use of aspirin for primary prevention is not warranted and treatment decisions need to be considered on a case-by-case basis.” For most people, the benefits of a daily aspirin simply don’t outweigh the risks.
That’s not the case for people who have already suffered heart attack or stroke, however. This new study did not look at those individuals, since that benefit has been well documented in other studies. The bigger debate in recent years has been the effect of aspirin on adults without known cardiovascular problems.
In a separate statement to the public, lead researcher Rao Seshasai said:
The beneficial effect of aspirin on preventing future cardiovascular disease events in people with established heart attacks or strokes is indisputable. We urge people with these conditions not to discontinue their medication unless advised to do so by their physicians for valid reasons.
For everyone else, it’s back to basics if you want to protect yourself from heart disease — eat a low-fat, low-sodium diet, and get enough exercise to get your heart pumping. And no, you can’t get that in a pill.