Ahhhh…. that morning cup of coffee – balm for the overindulgences of the night before, crutch against the depredations of the coming day – how could we survive without it? Or the one midmorning? Or the one after lunch? Or the one at afternoon tea…?
Why do we love it so much? It’s true that the taste of a well-brewed cup of coffee is beyond comparison. And the steamy comfort of a warm mug between your hands is undeniable. The ritual, too, must play a part, the preparation of this Godly beverage.
But none of these things is really what keeps us reaching for the coffee jar. We do it because of a crystalline white powder, the chemical name for which, even in its shortened form, is all but unpronounceable (1,3,7-trimethylxanthyine). We know it as caffeine, of course, and those of us who partake in the consumption of the roasted elixir are part of the largest drug using community on the face of the planet.
Caffeine – Popular and Prevalent
First discovered in 1819 by German chemist Friedrich Ferdinand Runge, caffeine is a naturally occurring stimulant found in over sixty plants around the world. Foremost among caffeine sources are: coffee, tea, kola nut, cocoa and guarana.
It’s prevalence and popularity have made it the most widely used drug in the world and coffee, one of the major sources of naturally occurring caffeine, is second only to oil as the most traded global commodity.
Today caffeine is found in everything from energy drinks to cough syrup, from headache pills to snack bars and chocolate. The ubiquity of its use as an ingredient in carbonated drinks is such that it is sometimes next to impossible to find a caffeine-free beverage in many convenience stores.
So what does this most popular of drugs actually do?
Caffeine is quickly absorbed by the body, circulating through the bloodstream in less than 30 minutes, with peak blood levels achieved about an hour after consumption. It has a half-life within the body of 6 hours, i.e. six hours after drinking that cup of coffee you’ll still have half of its caffeine in your blood.
The best known effect of caffeine is its ability to reduce fatigue, to act as a “pick me up”. To achieve this effect it exerts a profound influence on our brain chemistry. In a nutshell: caffeine blocks a neurotransmitter called adenosine which serves to calm the body. Once adenosine is blocked the body releases adrenaline and we enter a “fight or flight” state. Additionally, as caffeine is broken down in the liver, paraxanthine is produced, which provokes the release of extra fatty acids and glycerol into the bloodstream. A second metabolite, theophylline, elevates heart rate.
All of this results in reduced fatigue, greater concentration and alertness, improved coordination, elevated mood and increased heart, respiratory and metabolic rates. No wonder we like it so much!
Unfortunately, not everything caffeine does for us is good.
Excessive use of caffeine, or the use of caffeine by individuals who are overly sensitive to it, can produce an array of undesirable effects.
As a diuretic, caffeine can lead to dehydration, frequent urination and headaches. It also raises stomach acidity, which can lead to an upset stomach and gastro-intestinal pain.
It can delay sleep and reduce the quality of sleep that is achieved. This, plus caffeine’s inherent stimulatory properties, can lead to anxiety, depression, restlessness and irritability
Caffeine appears to increase levels of calcium excreted in the urine. If this is the case then consideration should be given to its role as a possible contributing factor in osteoporosis.
High levels of caffeine consumption by pregnant women have been linked to miscarriages and low birth weight babies.
Heavy caffeine use has also been linked with high blood pressure, heartburn, ulcers, infertility and heart disease.
Should I be Worried?
Before you race to the kitchen and bin that divine Brazilian dark roast espresso, though, it might be worth noting that the almost all of the unfortunate caffeine consequences noted above occur only when the drug is used in excessive amounts.
The general consensus is that moderate caffeine consumption (2 – 4 medium to strong cups per day) does not pose significant health risks to healthy adults.
If you’d like to know how much caffeine your favourite foods and drinks contain you can find a convenient table at www.faqs.org.
Mmmm, I think it’s coffee-time again.
To hear about one man’s struggle with caffeine addiction check out this video.