Peter Attia, MD, and Marty Makary, MD, MPH, discuss the rise of peanut allergies, a uniquely American epidemic. Beginning with a 1999 study estimating mild allergies at 0.5%, they examine the controversial 2000 pediatric guideline urging strict peanut avoidance in young children. This well-intentioned advice paradoxically caused allergy rates and severe anaphylactic reactions to soar. Highlighting the importance of early exposure for immune tolerance, they reference a 2015 study showing an 80% reduction in allergy risk with early peanut introduction. Despite clear evidence, reversing deeply ingrained public health guidelines proves to be a challenging yet critical task.