Why Stress Makes Us Sick

  Well, not all stress makes us sick. Stress can motivate and energize us—it helps us perform better in front of an audience or get psyched for an adventure, like white-water rafting on the Colorado River in chilly November (shout-out to Mike, Eric, and Frederique!) or skydiving from 13,000 feet (“terrifying” and “freeing” says my brave niece, Laura, pictured). Not surprisingly, skydiving triggers a “fight-or-flight” (literally!) stress hormone response. In one study, 39 men and women who tandem jumped for the first time had increases in cortisol, stress catecholamines, inflammatory cytokines (IL-12 and interferon-gamma), and natural killer cell numbers and gene expression. Manfred Schedlowski, a German researcher I heard at a conference way back in 1993, [...]