Mezcal is a distilled liquor made from maguey, which is a type of agave. It is similar to tequila, but tends to have a more smokey flavor, and can only come from certain areas of Mexico in order to be considered “true mezcal”. Illegal mezcal has a bad reputation, but Mark Sisson had an excellent experience with one batch of illegal mezcal.
Since mezcal is basically tequila made from a similar plant, if you include tequila in your Paleo lifestyle, there’s no reason you can’t include mezcal as well. It’s carb-free, and if you get the aged stuff, you’ll likely be getting a healthy dose of antioxidants to boot. Liquors often pick up antioxidants, in addition to flavor, from the oak barrels they are aged in and mezcal is no different.