Alcohol and marijuana have very different health effects - here's which is worse, according to science

It's a tough call. There are dozens of factors to account for, including how the substances affect your heart, brain, and behavior, and how likely you are to get hooked. Time is important, too - while some effects are noticeable immediately, others only begin to shape up after months or years of use.

The comparison is slightly unfair for another reason: While scientists have been researching the effects of alcohol for decades, the science of cannabis is a lot murkier due to its mostly illegal status.

Still, based on the studies we have, there appears to be a clear winner.