the chemical also has several indirect effects, including increases in adrenaline, serotonin, and dopamine. The release of dopamine is typical in drugs of abuse, and probably accounts for caffeine’s mood-enhancing qualities—the cup of optimism!—as well as the fact that it is habit-forming. Caffeine is also a vasodilator and can be mildly diuretic. It temporarily raises blood pressure and relaxes the body’s smooth muscles, which may account for coffee’s laxative effect. (This could explain some of coffee’s early popularity; constipation was a serious matter in seventeenth- and
...more
