To apply this to your example, cannabis was linked to heart disease in daily smokers. As one would expect, the study showed a dose dependent relationship with cannabis and risk.

Just like you can find “some” people who drink daily and become centenarians, you have to be careful about the way you characterize the risk. I believe the better data show more than 4 drinks a week does increase your health risk substantially.

In both cases, it seems like moderation is key, although I maintain cannabis is far safer when you compare the ratio of therapeutic to toxic dosage. But that’s acute risk, where the study you’re talking about is chronic risk.