Citation please. I really want to see this new research you speak of.
I have reviewed every single research paper on Cannabis that was issued up until few months ago. To date, there was no conclusive evidence that it causes any damage to any part of the body. There was no conclusive evidence that it causes any permanent changes at all. This is true even when it is abused beyond all reason. There is no possible toxic or dangerous dose for cannabis.
Alcohol, on the other hand, is 100% proven and guaranteed to cause permanent damage to every organ of the body when abused. We usually don't see the full extent of damage because a failed liver or alcohol poisoning claims most alcoholics before everything else has a chance to rot.