The problem is that capitalism drives people to push lies as fact, and manipulate people into believing those lies. "Well maybe people just shouldn't be so gullible" clearly isn't a solution, or the problem would be solved already.

I don't think that's an excuse to start banning books (and other media), but products like this -- especially anything that advocates a particular approach to health, nutrition, or medicine -- should be vetted by actual experts (more than one), and stores should be required to post disclaimers when the product doesn't pass muster.

Yes, there's the potential for abuse and shady dealings there, but I'd like to believe that the end result would still be better than what we have now.

Now, some people are just raised to believe in complete nonsense, so you're not going to save everyone by trying to educate them. But I think it'd help many people not get drawn in by (potentially dangerous) pseudoscience.