effect of marijuana smoke on atherosclerosis

non-professional medical subjective opinion: I think it's good for it.

Marijuana lowers blood pressure, usually by around 10-15 points. It also gently stimulates the parasympathetic nervous system, which expands blood vessels and capillaries and relaxes the nerves of the body (in contrast to the smypathetic nervous system, which is stimulated by nicotine, amphetamine, cocaine, etc., constricting blood vessels and raising blood pressure.) Cannabis also stimulates prolactin, like Viagra but gentler.That's why Viagra users are told not to use pot- when combined, they lower blood pressure so much that you can get faint and dizzy spells when you stand up, etc.

On the other hand, if you use pot and like it, Viagra shouldn't be necessary. 

No need to use a lot. The smallest amount needed to get an effect is what's best.