A daily, low-dose aspirin regimen for people above the age of 50 may not be the most effective way to further reduce their risk for cardiovascular disease (CVD), a new study has found.

Published in the National Institute for Health Research, the study claims “fine balance” exists between daily aspirin regimens and an overall reduction in CVD for people who are otherwise healthy. Relying on randomized controlled trials, meta-analyses, and systematic reviews, the research team culled 2,572 potentially relevant papers — using 27 that fit their strict criteria — and arrived at a conclusion that only weakly favored the regimens as beneficial.

"The risks are finely balanced and for now there is not the evidence to advise people to take it,” study leader Prof. Aileen Clarke told the BBC. "It would be lovely to say over-50s should take an aspirin a day and have much less cancer, but the research hasn't yet been done and we should be cautious.” Aspirin reduces the elderly’s increased risk for heart disease by thinning the blood, making it less likely to clot inside veins and arteries. Blood-thinners also reduce the rate of stroke. Some studies have even purported that cancer risks diminish through daily aspirin regimens.

The present study deems it risky, however, because on the other side of the “fine balance” is excessive bleeding. Blood that clots within a person’s body normally puts that person at risk for numerous cardiovascular problems; if the person is bleeding, however, clotting is the desired effect. A daily aspirin regimen makes this much more of a concern. "Aspirin is extremely important for many heart patients, but for people free of heart disease the jury is still out as the risks are likely to outweigh the benefits,” said Amy Thompson, senior cardiac nurse at the British Heart Foundation.

Cardiovascular disease most often affects the obese and the elderly, not to mention those who are genetically predisposed. Roughly one-third of the U.S. population is overweight, according to the Centers for Disease Control and Prevention. As the country’s waistline grows, so too does its risk for cardiovascular disease, as the fatty deposits in the body impede blood flow. The CDC pegs cardiovascular disease and stroke as the two leading causes of death in every ethnic group in the U.S.

Present research, while important for ruling out aspirin regimens as ineffective — and potentially harmful — at keeping CVD risks low, falls short of ruling conclusively on who can benefit, aside from the already high-risk groups, from taking the medication daily. "Further research is underway which will shed light on who else is likely to benefit the most from taking aspirin,” Thompson told the BBC. Until this research is carried out, consumers looking to reduce their risks of CVD should examine their family history and closely monitor their dietary habits, as a host of risk factors can contribute to CVD’s ultimate development, rather than one factor acting alone.