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Caffeine - Introduction

Caffeine is a naturally occurring compound found in the leaves, beans, and fruits of certain plants. In nature, it acts as a pesticide and as an inhibitor of seed germination, thus giving the plant a better chance of survival; many plant species contain trace amounts of caffeine that either kill or paralyze insects that attempt to feed on the plant. Certain seedlings that are still developing foliage contain high levels of caffeine since this is their only means of protection until they can reach a larger size and develop mechanical means of defence against insects to ensure their survival.

In humans, caffeine acts as a psychoactive stimulant drug and a mild diuretic and vaso-constrictor. It has the effect of temporarily warding off drowsiness and restoring alertness. In North America alone, approximately 90% of adults (and to a lesser extent children as well) consume caffeine on a daily basis; it is one of the few psychoactive substances that is not regulated or banned.

Although coffee was being ingested for its stimulating effects since the 9th century, the substance caffeine was actually discovered in 1819 by Friedrich Ferdinand Runge, a German chemist. He is the one who came up with the term ‘Kaffein’ for the bitter, white crystalline alkaloid compound which could be extracted from several plants.

While caffeine is often used as a generic term for the xanthine alkaloid compound irregardless of the source, purists employ the term caffeine when found specifically in the coffea plant and guaranine when found in guarana, mateine when found in mate, and theine when found in tea. Kola nuts, which give us cocoa and many other derived products, also contains caffeine.

Caffeine is found, either as a natural by-product or as an additive, in coffee, tea, cocoa, soft drinks and energy drinks and may also be found in chocolate bars, energy bars and some medications.

As a stimulant, caffeine acts on the brain and nervous system. In small doses, it can make you feel refreshed and focused. In large doses, you are likely to feel anxious and have difficulty sleeping. Caffeine, as a stimulant, works on the body similarly to the hormone adrenalin. The adrenal glands are located near the kidneys. When we are frightened or stressed, the adrenal glands inject adrenalin directly into the bloodstream. The results are dramatic and instantaneous, leading to an increased oxygen intake, a higher heart rate, and a short burst of physical energy.
As with most drugs, it is possible to develop a tolerance to caffeine, and therefore require greater amounts to achieve the same stimulating effects. Over time, it is possible to develop a dependence to caffeine.

Some symptoms of caffeine abuse or excessive intake are:

• A rise in body temperature;
• Frequent urination and dehydration;
• Dizziness and headaches;
• After the energy burst, an even greater feeling of fatigue;
• Heart palpitations;
• Restlessness and excitability;
• Anxiety and irritability;
• Trembling hands;
• Sleeplessness.

Ironically, although caffeine is often used in over-the-counter medicine against headaches, excessive intakes may also cause migraines and headaches in some people.

People who are ‘addicted’ to caffeine may feel withdrawal symptoms if they are unable to ingest it for some time. Withdrawal symptoms can include tiredness, crankiness, persistent headaches, sweating, and muscle pain. The easiest way to break caffeine dependence is to cut down gradually, giving your nervous system time to adapt to functioning without the drug.

How much is too much?
Your susceptibility to caffeine depends on your body mass, general state of health, metabolic rate, and whether or not you are used to getting regular doses of caffeine. Generally speaking, 500mg per day or less is considered an acceptable dose.