Medical marijuana appears to have some mitigating effect on opioid use and abuse, but the relationship is far from definitive.

The US researchers assessed seven studies, five of which concluded that medical marijuana might be associated with benefits such as decreased opioid overdose rates, decreased opioid use, improved quality of life and improved pain control.

The benefits were found to be weak to moderate overall, but statistically significant.

Specifically, the data suggested a 29% reduction in opioid overdoses in US states where medical marijuana was used, as well as a 44-64% reduction in opioid use among chronic pain patients, the authors revealed during a presentation at the American Society of Anesthesiologists’ annual meeting in Orlando, Florida.