Healthy people without a history of cardiovascular disease are unlikely to benefit from regular use of aspirin, according to a new British study.
Doctors have long recommended a daily dose of the painkiller to reduce the risk of heart attack or stroke, but the study found that aspirin also raised the risk of internal bleeding. The study, which was published online in the Archives of Internal Medicine, is the largest ever conducted on the effects of aspirin on people without cardiovascular disease.
Researchers at St. George’s University of London analyzed data from nine clinical trials involving over 100,000 participants with no prior history of cardiovascular disease. Half of the participants took aspirin and half took a placebo for about six years.
The researchers found that deaths related to cardiovascular disease occurred at essentially the same rate for people who did and did not take aspirin. There was a modest decrease in non-fatal heart attacks, but that benefit was almost entirely offset by a 30 percent increase in life-threatening or debilitating internal bleeding. This means that one stroke or heart attack was averted for every 120 people treated with aspirin, while one in 73 people taking aspirin suffered significant internal bleeding.
The lead author of the study emphasized that people with a history of heart conditions should not stop taking aspirin.
“The beneficial effect of aspirin on preventing future cardiovascular disease events in people with established heart attacks or strokes is indisputable,” said Dr. Rao Seshasai of also from St George’s University of London. “However, the benefits of aspirin in those individuals not known to have these conditions are far more modest than previously believed and, in fact, aspirin treatment may potentially result in considerable harm due to major bleeding.”
Many doctors prescribe regular aspirin for people without a previous history of heart attack or stroke, but who may be considered at risk of cardiovascular disease because of family history or obesity.
Some studies have also suggested that aspirin lowers the risk of cancer by reducing inflammation, which speeds the growth of blood vessels in tumors. The St. George study found that aspirin did not reduce the risk of death from cancer.
“There is an enormous interest in understanding the role of aspirin in cancer prevention, said Dr. Seshasai. “No evidence of benefit was found in the studies reviewed, but more research is needed given these were only of six years in duration.”