The pros and cons of your caffeine habit

Caffeine is a naturally occurring substance that affects the brain and behaviour (even if you don’t notice it). It can be found in many different drinks and foods, and in some medication.  

The good news is that moderate doses of caffeine can enhance alertness, concentration, problem-solving ability, and cognitive performance. Yay!

The bad news is that too much caffeine can lead to stomach upset, jitteriness, trembling, and sleep problems. Boo!

Caffeine facts

• Caffeine promotes alertness by inhibiting chemicals in the brain that promote sleep.  
• It is rapidly absorbed by the body and can reach peak levels within 30-70 minutes.  
• The half-life of caffeine (that is, the time it takes the body to eliminate 50% of what was consumed) can vary between 2-10 hours, so it may take up to 24 hours to fully eliminate it from the body.
• Too much caffeine can reduce the amount of calcium your body absorbs
• A healthy adult should consume no more than 400mg of caffeine a day, and no more than 200mg in a single dose.

Caffeine content

• Chocolate drinks: 5–10mg per 250ml
• Instant coffee per tsp: 60-80mg  
• Drip or percolated coffee: 150–240mg per 250ml
• Espresso coffees with milk such as latte: 105–110mg per 250ml
• Espresso coffee: 126mg per 30ml (single shot)
• Decaffeinated coffee: 2–6mg per tsp
• Black tea: 65–105mg per 250ml
• Green tea: 37-44mg per 250ml  
• Cola drinks: 40–49mg per 375ml
• Energy drinks: up to 160mg per 250ml
• Dark chocolate bar: 40-50mg per 55g serve
• Milk chocolate bar – 10mg per 50g serve

Caffeine and sleep

Some say caffeine should be avoided for at least 3 to 7 hours before going to sleep. Others say no caffeine after lunchtime if you have sleep problems. Many people find that their sleep improves with less caffeine or only having caffeine in the morning.

If you are trying to cut down your caffeine intake for a better night's sleep, it’s best to cut down slowly to avoid headaches, tiredness, and anxiety.  

A person's age, body weight, certain medications, liver health, and susceptibility to caffeine can all affect how long caffeine stays in the body.

Sources:

betterhealth.vic.gov.au

sleepfoundation.org

jeanhailes.org.au

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