Does Uncle John, the guy responsible for producing a 600-page book every year, drinking a lot of coffee? You better believe he does. Here’s how the good stuff works.
Caffeine affects neurotransmitters. Normally, those keep blood vessels mostly closed, but the stimulation by caffeine widens them, allowing more blood to flow right through them. The blood carries oxygen, of course, and that delicious, life-giving oxygen heads for the brain and body tissues, making you feel awake and refreshed. But that’s not all. Caffeine stimulates the production of the hormone, adrenaline, which famously makes the whole body speed up, particularly quickening the heartbeat.
Number 1 at Number 2
Coffee’s most famous effect on the body is as a stimulant: a cup or two perks you up and keeps you going…all the way until the time when you need more coffee. The second-most famous thing coffee does to the body—it keeps you…well, let’s just say it gets you to a place where you can read an Uncle John’s book. That’s because caffeine (as well as chlorogenic acids and other organic compounds) can lead to contracts in two different parts of the digestive system: the intestinal muscles, as well as the colon. (That’s called the gastrocolic reflex.) First, all that activity in the intestines forces whatever is in there further along, and into the colon, where more contractions push your breakfast to the rectum, and, well, you know what happens next. Water also helps the digestive system work in this way, although caffeine (and a cup of coffee packs a lot of it) is 60 percent more effective in its colon-jostling affects.
The Original Jitterbug
The caffeine in coffee is a stimulant, and a single brewed cup can contain anywhere from 50 to 100 mg of the stuff. The definition of a stimulant is anything that makes your body react by speeding up the central nervous system’s functions, which leads to you feeling more awake and alert. Too much caffeine, however, means that the central nervous system gets set to hyperspeed, which leads to too much awakeness and alertness. That, in turn produces the dreaded “jitters,” feelings of anxiety and nervousness along with a sense that your body is shaking.