have you read mark's book yet? he backs up all of his information with undeniable common sense and tons of studies, such as the nurses study.
that said, if people are skeptical, you're going to have a tough time convincing them that this is better than the eat-whole-wheat-and-bran-skip-the-yolks-and-red-meat stuff they've been listening to for decades. for me, i learned that the case against fat started when doctors were noticing health risks associated with diets high in red meat...and didn't take into account the potatoes, bread and sugary drinks...and realized that the knowledge that CW is based on was coming from really poorly executed studies. then the common sense of our evolution (as explained by mark) made me start seeing things differently, then the studies helped.
so, i guess my point is that having studies to show people is good, but they will continue to be skeptical in the face of science until they realize that something they've spent their life believing may, in fact, be untrue. they may always be skeptical, and that's ok. your change and your health will be the best proof for them.