It's 12:18 p.m., and by now, the glorious effects of your first coffee of the day are probably wearing off. Before you head off to Starbucks for that second cup, think about your poor adrenal glands. Caffeine gives you a mental boost by firing off neurons in the brain (sounds great, doesn't it?), which signals the pituitary to secrete hormones that get the adrenal glands to pump your body full of adrenaline. Over time, all this extra adrenal stimulation can wear out the glands, depleting your defense system, according to Natural News. For those of us who love coffee and all it does for big bursts of focus and creativity, this is lousy news, of course. So until you've got the guts to quit, just tell your adrenal glands you're sorry.