Caffeine

Caffeine is a naturally occurring compound found in the leaves and fruits of certain plants. Caffeine is found in coffee, tea, cocoa, cola soft drinks and energy drinks. It may also be found in chocolate bars, energy bars and some over-the-counter medications, like cough syrup and slimming tablets.

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.

Like many other drugs, it is possible to develop a tolerance to caffeine, which means ever greater doses are needed to achieve the same effect.

A short burst of energy
Stimulants like caffeine work on the body in similar ways to the hormone adrenalin. The adrenal glands are located near the kidneys. When we are frightened or stressed, the adrenal glands squirt adrenalin directly into the bloodstream. The results are dramatic and instantaneous, with an increase in breathing and heart rate, accompanied by a short burst of physical energy.

Some of the signs and symptoms of excessive amounts of caffeine include:

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

• Chocolate drinks – 30 to 60mg
• Instant coffee – 60 to 100mg
• Drip or percolated coffee – 100 to 150mg
• Espresso coffees – such as espresso or latte – 90 to 200mg
• Cola drinks – 35mg
• Decaffeinated coffee – around 3mg
• Tea – 30 to 100mg, depending on the type and strength of the brew (both black and green tea contain caffeine)
• Energy or sports drinks – such as Red Bull or ‘V’ – 80 to 90mg
• Dark chocolate bar – 40 to 50mg per 55g serve
• Guarana – can contain up to 100mg per one gram of guarana
• Caffeine tablets – such as No-Doz – 100mg per tablet.

• Pregnant women – limit your caffeine intake to 200mg per day or less, or avoid it altogether. Consuming high amounts of caffeine may increase your risk of miscarriage, experiencing a difficult birth and having a baby with a low birthweight.
• Athletes – caffeine is not classified as a prohibited substance under the World Anti-Doping Code 2005 Prohibited List. However, you should check the anti-doping rules of your particular sport to ensure caffeine is not specified as a restricted drug for that sport.
• Children – at present there are no guidelines for children’s intake of caffeine. Caffeine intake should be investigated if children are showing symptoms of irritability, inability to sleep, interrupted sleep or stomach upsets. Remember that caffeine is present in many soft drinks and chocolate, not just coffee and tea.

• Your doctor
• Pharmacist
• An Accredited Practising Dietitian, contact the Dietitians Association of Australia

• Caffeine is a stimulant drug that acts on the brain and nervous system.
• Like many other drugs, it is possible to become dependent on caffeine.
• Pregnant women, athletes and children should limit their intake of caffeine.

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