Taking a low-dose aspirin daily has no benefit in warding off dementia, disability or cardiovascular disease in healthy, older adults, and may instead increase their risk of serious and potentially life-threatening bleeding, according to a published on Sunday.

The study's results, published in The New England Journal of Medicine, add to a contentious debate among doctors over who exactly should take the drug as a preventative measure.

鈥淐linical guidelines note the benefits of aspirin for preventing heart attacks and strokes in persons with vascular conditions such as coronary artery disease,鈥 said Richard J. Hodes, the director of the National Institute on Aging at the National Institutes of Health, which funded the study, in a news release. 鈥淭he concern has been uncertainty about whether aspirin is beneficial for otherwise healthy older people without those conditions. This shows why it is important to conduct this type of research.鈥

Doctors in Australia and the United States enrolled more than 19,000 healthy people 鈥 whites over the age of 70 and blacks and Hispanics aged 65 and older 鈥 in the study. None of the participants was known to suffer from heart disease, dementia or persistent physical disability at the time of enrollment.

Half of those enrolled took low-dose aspirin 鈥 100 milligrams 鈥 daily, while the rest took a placebo each day for an average of 4.7 years.

The doctors found that taking a daily low-dose aspirin did not decrease the risk of heart attack or stroke among participants when compared with the placebo group. It also did not prolong 鈥渉ealthy independent living鈥 鈥 life free of dementia or persistent physical disability.

Instead, researchers found that aspirin use was associated with an increased risk of bleeding in the digestive tract and the brain, with 3.8 per cent of people on the drug suffering from those conditions, compared to 2.7 per cent in the placebo group.

Doctors unexpectedly also found that the group taking aspirin died at a slightly higher rate than the placebo group, with most of those deaths attributed to cancer. The authors said that 鈥渢hese findings should be interpreted with caution鈥 until more studies are completed, particularly because other research has concluded that the drug helps reduce the risk of colorectal cancer.

鈥淭he increase in cancer deaths in study participants in the aspirin group was surprising, given prior studies suggesting aspirin use improved cancer outcomes,鈥 Leslie Ford, the associate director of clinical research at the National Cancer Institute鈥檚 Division of Cancer Prevention, said in a news release. 鈥淯ntil we have additional data, these findings should be interpreted with caution.鈥