The last time this column looked at the subject of caffeine I received a few comments from people claiming that I was really scraping the bottom of the barrel in terms of drug use. Could I really justify talking about caffeine in a column such as this? Well, when you consider that caffeine is the most commonly consumed psychoactive drug in the world and that there is rarely any discussion on the risks associated with its use, I believe an occasional update is important.
It is estimated that the intake of caffeine averages between 80 and 400 milligrams per person per day -“ which works out to be between three and five cups of coffee every day. The drug has positive effects such as enhanced mental alertness, increased energy, and a sense of wellbeing -“ and apart from the taste, most people would agree that is why they have that daily cup of coffee.
The half-life (the time it takes the plasma levels of the drug to fall in the body by 50 percent) of caffeine is about 3.5 to 5 hours in most adults, which accounts for the problems that some people have with sleep disturbances when they drink coffee. Caffeine’s half-life is extended in infants, in pregnant women and in the elderly. Heavy consumption of coffee (12 or more cups per day) can cause problems such as agitation, anxiety, tremors, rapid breathing and insomnia. The lethal dose of caffeine is believed to be about 10 grams, which is roughly equivalent to 100 cups of coffee. As a result, death from caffeine is highly unusual, and the drug is usually considered to be relatively safe.
However, there are some people who should stay well away from caffeine products, particularly those with anxiety disorders. In fact there is even a clinical syndrome known as caffeinism which can be produced by the overuse or overdoses of caffeine. Symptoms include increases in anxiety, agitation, insomnia and mood changes. The condition is usually dose-related, with more than five cups of coffee drunk over a short period of time causing the most unpleasant effects. However, if you are predisposed to an anxiety disorder such as panic attacks, much lower doses of caffeine could trigger the problem.
Caffeine withdrawal is common among those people who attempt to stop their coffee consumption. People who drink the most coffee complain of headaches, drowsiness, fatigue and a generally negative mood state upon withdrawal from the drug. These symptoms typically begin slowly, maximise after one or two days and cease a few days after that. And don’t think that because you’re a tea drinker you won’t have these problems -“ a cup of strongly brewed tea is likely to have a very similar caffeine content to a cup of coffee.
There are, however, some benefits to a good cup of coffee. Caffeine constricts blood vessels, thus decreasing blood flow to the brain by about 30 percent. This reduces pressure on the brain and can effect striking relief from headaches, especially migraines. Another positive benefit is bronchial relaxation which can cause relief to asthma sufferers.
Remember: if you do not want any negative consequences, do not use the drug, and no matter how many times you have used a substance, never be blas?