In contrast to some recent research, a new study finds no evidence that men who use aspirin or ibuprofen are at any lower risk of an enlarged prostate.
The findings, reported in the British Journal of Urology International, conflict with an earlier study finding that benign prostatic hyperplasia -- the medical term for an enlarged prostate -- was less common in men who regularly used NSAIDs.
NSAIDs, or non-steroidal anti-inflammatory drugs, include common painkillers like aspirin, ibuprofen and naproxen.
Benign prostatic hyperplasia (BPH), meanwhile, is thought to involve inflammation. So that raises the possibility that NSAIDs could help limit prostate enlargement, explained Siobhan Sutcliffe, the lead researcher on the new study.
That's important because although it's natural for a man's prostate gland to enlarge with age, it can eventually lead to bothersome problems -- like urine leakage or frequent trips to the bathroom at night.
In the U.S., men make about 4.5 million doctor visits each year due to BPH symptoms, according to the National Institutes of Health.
A 2006 study had hinted that NSAIDs could offer some protection. Researchers found that of nearly 2,500 men they followed for a dozen years, those who used an NSAID everyday were less likely to develop BPH.
But that type of study can only show there's a correlation between NSAID use and BPH risk -- and not that the painkillers actually prevent prostate enlargement.
So Sutcliffe's team tried to confirm the connection in another study group: 4,771 men ages 55 to 74 who were part of a cancer-screening trial. At the start of that study, the men were asked about their use of aspirin and ibuprofen over the past year.
Over the next nine years, 31 percent were newly diagnosed with BPH. But there was no evidence that the risk was any lower for men who'd been regular NSAID users at the study's start.
Still, it's not the end of the story for NSAIDs and the risk of prostate enlargement, said Sutcliffe, of Washington University School of Medicine in St. Louis.
"This is really still in the early stages of investigation," she told Reuters Health.
One limit with the current study, Sutcliffe said, is that it looked only at men's NSAID use in the year before entering the trial. It's possible that longer-term use has different effects.
And then there's the 2006 study that did find a lower BPH risk among NSAID users. It's not clear why the current study came to different conclusions, according to Sutcliffe.
One reason, she speculated, could be that men in the studies tended to have different reasons for using NSAIDs. But there was no information on why men were using the painkillers, so that's just a guess.
If future studies do find that NSAID users have a lower BPH risk, then what? For one, Sutcliffe said, it would suggest that low-dose aspirin -- which many older adults already take for their heart health -- may have an added benefit.
It would also raise the possibility that NSAIDs could help treat BPH symptoms.
There are already ways to manage urinary symptoms. Some men find enough relief from lifestyle changes, like cutting down on caffeine and alcohol, and limiting fluids before bedtime.
Other men with bothersome BPH symptoms take medication. Most commonly, that means blood pressure drugs called alpha 1-blockers, which help relax the muscles of the bladder and prostate, and make urination easier. Two other drugs, finasteride and dutasteride, are sometimes prescribed; they work by lowering levels of a hormone that contributes to prostate enlargement.