While I can certainly understand the frustration, I wouldn't recommend physically assulting someone. Besides...the stupidity of another person isn't worth assault charges. Doesn't mean you can't THINK about doing it, though!
Seriously...stick with what you KNOW is true and ignore the uninformed idiots who just repeat what they've heard without actually checking to see if it's true or not. As for your partner, I'd encouarge them to see if them can find any legitimate studies that support any of the BS that they have been believing.