Humanity learned about coffee only a few centuries ago, and the story of coffee began in Ethiopia, and then took off in Yemen to become the “fuel for humanity” with which it “works every morning.”
Caffeine undoubtedly causes a biological change in our bodies. Dr. Thomas Sanders, Professor of Nutrition and Dietetics at King’s College London, explained to the British newspaper The Telegraph the changes that occur to the body from the moment we take the first sip of coffee.
8 a.m.: First sip
Some people need a dose of caffeine to get out of bed in the morning, so drinking coffee or tea in the morning is completely normal. What happens after that depends on the nature of the body and the amount you consume.
As a general rule, the average half-life of caffeine in the body is between 5 and 6 hours for healthy adults (the time that passes before the concentration of caffeine in the blood halves). “The important thing to stress is that there is a great deal of variation in individual response to coffee; some of that may be genetic, and there may also be gender differences in the way we analyze coffee as well,” Professor Sanders says.
8.05am: Placebo effect
Your mood changes immediately and you feel happy with every sip. Do not be too happy, as this is not the effect of coffee. This immediate change in your mood is likely to be a placebo effect and not a biological change. Your mood improves because you love coffee no more.
Professor Sanders says: “To feel the effects of coffee, you have to allow it to absorb and reach the bloodstream. What you feel at this stage is likely to be a psychological effect only.”
It takes about 20 minutes for caffeine to be absorbed into your bloodstream, so you should start feeling the positive effects now.
8.20am: Increased energy and increased heart rate
“The first thing you feel is an increase in your heart rate,” says Professor Sanders. “If you’re in a sluggish state, it will give you a slight boost of energy, which is why many people rely on a cup of coffee in the morning.” This is also why people with heart conditions, such as arrhythmia, are advised to avoid drinking strong stimulant drinks in the morning.
Your mental performance actually improves during these 20 minutes; You will feel more alert, energetic and able to tackle tasks. The influx of coffee into the bloodstream causes adrenaline to be released, and this activates our “fight or flight” mode.
“Your concentration levels will probably continue to improve gradually from here, peaking after about an hour,” says Professor Sanders. “It really depends on how much caffeine you have consumed, and your metabolism.”
Also at the 20-minute mark comes one of the most interesting effects of caffeine, which is your overwhelming happiness while holding your cup of coffee.
8.30am: Nature’s call
Caffeine is a diuretic, so about half an hour after your morning cup, you may feel the need to urinate (this can happen as quickly as 5 minutes after drinking it). One study found that a small cup of coffee will not cause dehydration, meaning that those who consume coffee in moderate amounts do not need to compensate with excess water.
Professor Sanders warns: “People with bladder or prostate problems may want to be more careful when drinking a cup of coffee, as the diuretic effect may be more powerful.”
9.30am: Bowel stimulation
Compounds in coffee stimulate the intestines, which causes waste to be pushed out faster than usual. So, says Professor Sanders, 60 to 90 minutes after drinking coffee, you may feel a “slight cramp in the intestines,” which indicates it’s time for another visit to the bathroom. This happens with decaf coffee too, it’s another substance in coffee, not caffeine.
“Drinking coffee has been associated with a lower risk of colorectal cancer, with one view being its effect on bowel movements,” says Professor Sanders.
Coffee has also been shown to reduce the risk of type 2 diabetes. A Harvard study showed that people who increased their coffee intake over a 4-year period had an 11% lower risk of developing the disease than those who did not increase their coffee consumption.
There is a debate in the medical community about the extent to which coffee can irritate stomach acids. Professor Sanders says: “For some people, black coffee can increase stomach acid production; but not always. The evidence is inconclusive, although some people say if your stomach is acidic, avoid black coffee.”
11am: Horrific collapse
Now you may have accomplished your long to-do list, but you’re starting to feel really tired. My caffeine level has decreased. Signs of low caffeine levels include headaches, excessive fatigue, inability to concentrate, and irritability.
12 noon: Cravings for more caffeine
Professor Sanders says: “When you consume something for a period of time, the receptors in your brain adapt to it. It takes some time for this process to return to normal after removing coffee from the system, as your body anticipates that you will have another dose, and this will wake you up.”
This expectation is what drives many of us to reach for an afternoon cup of coffee, and that starts the cycle all over again.