IMO, the real question is "What claims do you believe about garlic and why do you believe them?" Regardless of whether you want a "western medicine" answer, if you believe garlic will help your health in some way, then you -- again, IMO -- ought to have good reason for that belief. "I've heard" and "people [...] swear by it" aren't very good ways of determining effectiveness. Adopting an unsupported belief, and then persisting in it until/unless someone proves you wrong, also isn't a very good way. Whether or not they're supported, and whether or not they're "western", claims == marketing, in the big business of health. Word-of-mouth marketing ("people swear by"), television ads, and even published papers are just different flavors of that. Some claims/marketing are more plausible than others, and it's best to have a good reason for deciding which ones to believe and which to dismiss.