For today’s edition of Dear Mark, we’ve got just two questions, but they’re meaty ones. The first concerns a new study seeming to claim that all the foods we hold dear on the Primal eating plan — or at least a big portion of them — cause Alzheimer’s disease. Could it be true, or is the study, which is an epidemiological massage of existing data, maybe not quite so definitive as that? Also, what if we had a study showing that exact opposite: that following a Primal lifestyle (not just diet) could actually reverse Alzheimer’s-associated cognitive decline? Then, I discuss the role of competitiveness in life. Having been a top endurance athlete, I know a little bit about the subject. What does it mean these days, though?