Whether you need it to wake up, stay productive, or you simply love the taste, coffee is here to stay. An estimated 80 percent of Americans drink the roasted bean beverage; many of us can’t even start our day without that kick of caffeine.
But have you ever wondered what actually happens to your body when you drink coffee? No matter how you take it—latte, cold brew, espresso—coffee works through your entire system. It affects a host of processes in your body, including digestion, metabolism, and vision. It makes you feel more awake, focused, and energetic; but too much can also backfire.
After 10 Minutes: Your Heart Beats Faster
It takes as few as 10 minutes for caffeine to enter the blood stream and start working after drinking coffee. You may experience a short but dramatic increase in blood pressure and heart rate.
It remains unclear what exactly causes the blood pressure spike. Some researchers believe that caffeine blocks a hormone that helps keep your arteries widened. Others think caffeine causes adrenal glands to release more adrenaline, which accelerates blood circulation and increases breathing rate. In any case, drinking coffee makes your heart beat faster.
20 Minutes: You Think Faster
Within 20 minutes of drinking coffee, the caffeine causes adrenaline to flood your body. Adrenaline causes the “fight or flight” response, a survival mechanism that forces you to make quick decisions when dealing with an immediate threat. The fight-or-flight mechanism gives you a mild boost to attention and reaction, allowing you to think faster.
20 Minutes: You Feel Happier
Many people start their day with coffee because it actually makes them happier on a chemical level. Following that adrenaline rush, dopamine, the “happy hormone” is released. This can elevate our moods and increase feeling of happiness.
30 Minutes: Sight Improves
If you wake up blurry-eyed and then feel like your vision improves after downing a cup of Joe, you’re not imagining things. Thanks to the fight-or-flight mechanism, your pupils dilate slightly, and you might actually have sharper vision for a short period of time.
40 Minutes: You Feel Stronger
4 Hours: The Energy Crash
After about 4 hours of downing that cup of coffee, the effects of the caffeine start to diminish. The feeling of energy you have starts to wear off, not necessarily because you have less energy but because your body is leaving the fight-or-flight mode it was in. If you find your energy dipping later in the day, that morning cup of coffee may well be to blame.
6 Hours: The Bathroom Trips
If you choose the coffee shop for your first date, the last thing you want to do is drink your coffee too fast. That will leave you heading for the bathroom, interrupting meaningful together time or, worse, making a bad impression. Caffeine stimulates the bladder and the bowels, which means that the more the stimulant is consumed, the greater desire is to urinate. Caffeine also increases blood flow to the kidneys and at the same time reduces absorption of water and sodium. This results in the body’s increased urgency to get rid of liquid—something to avoid for people with irritable bowel syndrome.