When the innovative Arabs of ninth-century Yemen first concocted a beverage based on the bunn cherry, little could they have suspected the impact it would have on the world. We know this drink today as coffee and its active ingredient, caffeine, is by far the most popular recreational stimulant drug the world has ever known. The American Psychiatric Association (APA) suggests that between 80 and 85 per cent of all adults consume caffeine in any given year. Most commonly ingested in the form of tea and coffee, caffeine can also be found in chocolate, soft drinks, over-the-counter analgesics (pain killers) and increasingly as an additive to weight loss aids.
In the UAE the average daily caffeine intake is about 167 milligrams - fairly modest compared with the Swedes, who manage, on average, close to 400 milligrams a day. Caffeine or 1,3,7-trimethylxanthine, as it is known in chemical circles, was first identified in 1819 by the German chemist Friedrich Ferdinand. Anyone who has ever drunk a decent cup of coffee will be familiar with the most obvious effects of caffeine - increased arousal, mental alertness and, if you drink too much, perhaps insomnia and mild agitation. In relatively massive doses caffeine can be fatal, but you would have to drink in excess of 100 cups of coffee to imbibe a lethal dose.
Caffeine achieves its stimulant effects by interfering with adenosine, one the brain's naturally occurring chemicals. Caffeine is an adenosine antagonist, meaning it reduces adenosine activity and thereby negates adenosine's inhibitory effects on other important neurotransmitters (brain chemicals), most notably dopamine which, among other things, is implicated in movement, motivation and pleasure.
Our morning coffee's ability to alter specific signalling activity in the brain makes it a psychoactive substance, sharing biochemical similarities with other more powerful and infamous psychoactive stimulant drugs such as cocaine. Arguably, as a consequence of its similarity to other stimulant drugs, caffeine and its host, coffee, have had and will continue to have their share of controversies. For example, early in the beverage's history Islamic Jurists hotly debated its permissibility, eventually ruling in favour of the bean-derived libation. History also tells us of Khair Beg, the governor of Mecca, whose attempt in 1511 to ban coffee was both massively unpopular and ultimately unsuccessful. Similarly, and more recently, the Mormon Church encouraged its adherents to abstain from caffeinated beverages, and any substance which "creates an appetite for its self".
The idea that caffeine can be viewed as a drug of dependence is still being scientifically and conceptually contested. In clinical reality few people could be described as being seriously caffeine dependent and as experiencing significant problems in social and/or occupational functioning as a result of caffeine consumption. However, caffeine-related problems do exist and they are serious enough for the APA to recognise "caffeine intoxication" as a diagnosable entity, along with the more tentative caffeine withdrawal and caffeine-induced anxiety and sleep disorders.
Caffeine intoxication, according to the APA, is characterised by restlessness, nervousness, insomnia, gastrointestinal problems, muscle twitching, rapid heartbeats (tachycardia), rambling flow of thoughts or speech, psychomotor agitation and, in rare cases, death. The prevalence of caffeine-related disorders is at present unknown however, the recent proliferation and popularity of caffeine-based "energy drinks" has brought caffeine intoxication into renewed focus.
These drinks often court controversy; for example "Blow" and "Cocaine," two of the more outrageously named energy drinks, make obvious associations with illegal stimulant drugs and each claims to be more powerful and better able to out-energise its competitors. Despite the marketing hype, these energy drinks contain highly variable amounts of caffeine. This has led some experts to call for clearer labelling of the caffeine content of such products.
Many of these drinks are marketed as "dietary supplements" so the 71-milligram limit set by the US Food and Drug Administration for soft drinks does not apply. The so-called energy drinks may vary in caffeine content from anywhere between 50 to 500 milligrams, greatly increasing the likelihood of caffeine intoxication. More worrying are the findings of a recent prospective study suggesting energy drink consumption by students could be linked to the non-medical use of prescription stimulant drugs (amphetamine and methylphenidate). These findings have raised concerns that hyper-caffeinated energy drinks may be acting as a "gateway" to harder stimulant drugs.
What goes up must come down: caffeine withdrawal, as the APA refers to it, occurs with the abrupt cessation or reduction in caffeine intake. This phenomenon is most common in those who have been heavy caffeine users (500mg per day). However, it is also occasionally reported by those with more moderate caffeine consumption habits (100mg per day). The key symptoms may include headache, fatigue, drowsiness, anxiety, depression and nausea or vomiting. Many people also experience diminished cognitive performance, especially on tasks requiring vigilance.
It is not unusual for individuals to seek medical treatment for these symptoms without actually attributing their cause to caffeine withdrawal. Despite the risk of intoxication and the prospect of having to some day suffer from withdrawal symptoms, we cannot paint too negative a picture of caffeine. Aside from the obvious social and pharmacologically (drug) mediated enjoyment caffeine gives to millions of moderate coffee and tea drinkers, it has also been shown to improve performance of various tasks requiring focused attention.
Dr Roland Griffiths, a neuroscientist at the Johns Hopkins School of Medicine in Baltimore, has spent over two decades studying caffeine and its effects. Dr Griffiths suggests it is unclear if there is a net benefit to mankind's ubiquitous consumption of caffeine. He suggests that if you need a quick pick-me-up to stay focused on the job, then it is a benefit. However, when you get addicted and can't function properly without it, then it is more bane than benefit. Ultimately he suggests caffeine is a drug and should be accorded the same respect as a drug. Consuming it is an adult decision.