Sept. 17 (UPI) -- If healthy older people take a low dose of aspirin daily, it may not lead to a longer healthy life free of dementia and persistent physical disability, according to a new study.
But researchers found in a study of 19,114 people conducted in the United States and Australia that the risk of dying from a range of causes, including cancer and heart disease, varied. Their findings were published Sunday in The New England Journal of Medicine.
Aspirin has been touted as preventing heart attacks and strokes in people with vascular conditions such as coronary artery disease.
"The concern has been uncertainty about whether aspirin is beneficial for otherwise healthy older people without those conditions," director Dr. Richard J. Hodes of the National Institute on Aging, which partially funded the study and is part of the National Institutes of Health, said in a press release. "This study shows why it is so important to conduct this type of research, so that we can gain a fuller picture of aspirin's benefits and risks among healthy older persons."
In the ASPirin in Reducing Events in the Elderly trial, 16,703 people in Australia and 2,411 in the United States were enrolled and followed up for an average of 4.7 years. The study began in 2010. In the final 12 months of the trial, 62.1 percent of the participants in the aspirin group and 64.1 percent of those in the placebo group reported that they were still taking their assigned dosage.
The minimum age was 70; 65 in the United States for African-American and Hispanic individuals because of their higher risk for dementia and cardiovascular disease. All participants had to be free of dementia or a physical disability.
Among the people assigned to take aspirin, 90.3 percent remained alive at the end of the treatment without persistent physical disability or dementia. That compares with 90.5 percent of those taking a placebo. Also, the rates of physical disability dementia were similar in both groups.
Significant bleeding, a known risk of regular aspirin use, was associated with a significantly increased risk, primarily in the gastrointestinal tract and brain. Hemorrhagic stroke, bleeding in the brain, gastrointestinal hemorrhages or hemorrhages at other sites that required transfusion or hospitalization occurred in 361 people on aspirin and in 265 taking the placebo.
They found that the rates for major cardiovascular events, which including coronary heart disease, nonfatal heart attacks, and fatal and nonfatal ischemic stroke, were similar in both groups. In the aspirin group, 448 people experienced cardiovascular events compared with 474 people in the placebo group.
The study found the higher death rate in the aspirin-treated group was due primarily to a higher rate of cancer deaths. But this small difference could be due to chance, researchers said.
Half the people who died in the trial had some type of cancer. Heart disease and stroke accounted for 19 percent of the deaths and major bleeding for 5 percent.
"The increase in cancer deaths in study participants in the aspirin group was surprising, given prior studies suggesting aspirin use improved cancer outcomes," Dr. Leslie Ford, associate director for clinical research in the National Cancer Institute's Division of Cancer Prevention, said. "Analysis of all the cancer-related data from the trial is underway and until we have additional data, these findings should be interpreted with caution."
Continuing follow-up of the ASPREE participants is crucial, said Dr. Evan Hadley, director of NIA's Division of Geriatrics and Clinical Gerontology.
"These initial findings will help to clarify the role of aspirin in disease prevention for older adults, but much more needs to be learned," Hadley said.
Hadley noted only 11 percent of participants had regularly taken low-dose aspirin before entering the study.
Older adults should follow the advice from their own physicians about daily aspirin use, Hadley said.