There's a reason people have been swapping coffee for “healthier” alternatives like green tea and mushroom brews. While green tea also contains caffeine, it also contains L-theanine, an amino acid that promotes calm and helps counteract caffeine's negative effects like insomnia, panic disorders, and anxiety. It's true that a couple of cups of coffee won't kill you, and might make you feel invincible, but people are realizing that the benefits may not outweigh the cost or heart palpitations. Tha…