How to Explain Legions of Alt Med Believers?

I have a family member with some apparent gastrointestinal issues. The other night, while visiting, she was belching like a frat house drunkard. The episodes picked up in intensity after dinner. It was quite the entertainment for my two boys, who began gulping their grape juice to keep up with their best imitations. Amid the barnyard display, I learn this is a recurring problem for my poor relative and that she's treating it with colonics. I tried to reason with her, explaining that there is no scientific basis for colonic cleanses. It was no use and I eventually (and stupidly) resorted to mockery, which, of course, gave my relative all the reason she needed to tune me out. "You're always so negative on anything that is a natural health solution," my relative said to me, which was a reference to our previous discussions on alternative medicine. Yes, she is believer and yes, my previous attempts to undermine that faith fell on deaf ears. My relative is not uncommon. There are millions of very intelligent people who have bought into the mythology of alternative medicine, especially the claims of homeopathy. The evidence is out there that this stuff is bogus. So why do many believers in alternative medicine discount science? Are they in denial? Not properly informed by journalists? What's the story here?