Caffeine is a bitter substance derived from the leaves, fruit and seeds of various plants and acts as a natural pesticide against threatening insects.
Caffeine is of course found in high amounts in the seeds of the coffee plant and the leaves of the tea bush but it’s also commonly found in:
kola nuts – used to flavour cola drinks
guarana berries - which contain about twice the amount of caffeine as coffee beans
cacao pods – used to make chocolate products
The effects of caffeine on the body
Caffeine is a central nervous system stimulant which can increase your alertness and give you an energy boost. In the short term it can reduce physical tiredness, make you think faster and more clearly, increase your focus and improve your physical coordination.
As a stimulant, too much caffeine can make you anxious, jittery, restless or irritable. It can also stop you from sleeping well and may even cause dizziness, abnormal heart rhythms, headaches or other problems. In some people, too much caffeine can significantly increase blood pressure.
If you’ve been using caffeine regularly and you suddenly stop you may get symptoms associated with withdrawal, which can include headaches, temporary feelings of depression, muscle aches and irritability.
The dependency cycle can be hard to break so if you experience these symptoms, try to persevere until they stop rather than just taking in more caffeine to make them disappear.
The main sources of dietary caffeine
Here is a rough indication of how much caffeine there is in common sources:
Coffee – depending on type, generally between 60-150mg
Tea – standard black tea contains between 40-80mg
Cola drinks – a standard 330ml can contains around 30-40mg
Energy drinks - a 250ml can contains around 70-100mg
Chocolate – a 50g bar of chocolate contains around 30-50mg
Other sources of caffeine
Caffeine is also found in a number of different types of prescription and over the counter medicines, including some weight control products, cold and flu treatments and painkillers.
Recommended limits and toxic levels
The generally recommended limit for caffeine intake is somewhere around 300 mg per day depending on body size, sex and degree of tolerance - although pregnant women are advised to keep within 200mg per day.
If you have heart problems you should discuss your caffeine intake with your doctor as it will affect how hard your heart works.
If you suffer from anxiety problems or panic attacks you may find that caffeine will make you feel worse and if you’re not sleeping well or are prone to digestive upsets or any type of inflammatory bowel condition then reducing your caffeine intake may help.
Top tips for reducing your caffeine intake
Although caffeine can be addictive, cutting back to within healthy limits doesn’t need to be difficult, especially if you do it gradually over a week or two - here are some effective tips:
Switch to decaffeinated coffee or tea
Replace energy drinks with caffeine-free soft drinks, fruit and vegetable juices, fruit smoothies and squashes (diet versions preferably).
Try alternative hot drinks such as fruit and herbal teas, green tea, chai and roasted grain drinks.