perhaps it is not the action of sex, but the thoughts associated to the action that needs more examination. here are my thoughts on this topic. studies have indicated psychedelic drugs have a property about them that aids in smoking cessation. nicitine addiction is similar to being in a state of seeking sexual arousal as i imagine you know. both activities, smoking and having sex, can be enjoyable if done in moderation, but have very real health risks attached. sometimes when your mind is opened up, like on a psychedelic or meditative state you can change your outlook.
you could also try to work out at the gym. just pick healthy sex partners. don't become ill.