For today’s edition of Dear Mark, I’m answering two questions. The first comes from Lucas, a man whose wife is unable to eat meat without feeling sick to her stomach. As a result, she’s interested in pursuing a Pegan way of eating, or “paleo-vegan.” Is it possible to be healthy while emphasizing plant foods and avoiding most meat? Is there anything she should watch out for? And last but not least, what’s the deal with commuting to work on your bike amidst urban air pollution? We all know that active commutes are supposed to be healthier than riding in a metal box, but do the negatives of breathing all those airborne particulates outweigh the positives of riding your bike? Find out what I think.