Understanding the Effects of Caffeine
Many people will tell you that a good cup of tea or coffee can solve any problem, but do the benefits outweigh the side-effects of caffeine?
Caffeine is a powerful natural stimulant – the only food substance that actually mimics the body’s natural stress response, increasing heart rate and mental alertness. Many people find that a cup of coffee or strong tea helps them wake up in the morning, boosts their energy throughout the day and keeps them awake when working or driving home late at night. It can heighten awareness and improve reaction time: research has shown that athletes get a better workout if they take small amounts before hitting the gym.
The Dangers of Caffeine
There are undoubtedly benefits, but there is also a danger that caffeine can become addictive and can adversely affect sleep patterns and general behaviour. Caffeine addicts may suffer from withdrawal symptoms if deprived of their ‘fix’, including headaches, fatigue and depression. As with all things, moderation is the way to go – now enjoy that cup of coffee!
How Much Caffeine is good for you?
Caffeine is the most widely used drug in the world – virtually everyone consumes it in some form every day. It is found in coffee beans, tea, cola, nuts and cocoa beans: the recommended daily maximum is 450mg for the average adult.
For a cup of coffee (double these values for a large mug):
- Decaffeinated – 2mg
- Instant – 60mg
- Freshly brewed – 105mg
- Cappuccino – 100mg
- Espresso – 100mg
- Cup of tea – 36mg
- Can of cola – 45mg
- Milk chocolate – 20mg
- Dark chocolate – 37mg
The Benefits of Caffeine
Unless you are pregnant or particularly affected be caffeine, there’s no reason not to enjoy its stimulating effects. Just make sure you don’t become addicted.
Short Term Energy Boost
Almost all of us have turned to a cup of tea or coffee, even chocolate, for a quick pick-me-up. This is because caffeine has a stimulatory effect on nerve cell activity in your brain and causes its blood vessels to constrict. Your pituitary gland responds to this increased brain cell activity by acting as though the body is facing an emergency situation, and stimulates the production or adrenaline.
Adrenaline has the following effects:
- You pupils and airways dilate
- Your heart rate increases
- Your blood pressure rises, as the blood vessels closer to the surface of your skin constrict
- Blood flow to your stomach is greatly reduced
- The liver releases sugar into the bloodstream to provide extra energy
This can help you to feel more alert and excited, which is useful before any competitive sport, such as a sprint or sports match; a job interview or exam; or if you’re feeling sleepy while driving.
Caffeine to Improve your Mood
Like all stimulants, caffeine raises your levels of dopamine, a neurotransmitter that activates the pleasure centre of the brain and lifts your mood. This feeling of pleasure is an important factor in the addictive properties of caffeine; it belongs to the same chemical group as amphetamines and cocaine. The effects of caffeine are less powerful than those of cocaine, but it works in a similar way and is just as addictive.
This can be problematic because, as the adrenaline released by coffee wears off, you may feel tired and depressed and immediately reach for another mug. It’s not healthy for your body to be in a constant state of emergency all the time and many caffeine addicts become jumpy and irritable rather than alert.
Caffeine to keep you Awake
Caffeine has a significant effect on sleep. It takes around 12 hours for caffeine to leave your system, meaning that if you have a large mug of coffee at 4pm, then by 10pm there may still be 100mg of caffeine in your system. This may be advantageous if you’re working late or on the night shift, but it can cause problems when you do get home and want to get some sleep!
Back to Normal
Research has indicated that’s coffee’s stimulant properties work best on people who are consistently performing under par due to fatigue, stress or boredom, suggesting that it normalises impaired performance rather than enhancing it under normal conditions.
Affects on Sleep
If you’ve had a lot of coffee late in the evening, you may be able to fall asleep, but will unlikely to achieve the deep sleep state that your body requires. As a result, you may wake feeling tired – and instinctively reach for a cup of coffee to wake you up, so helping to repeat the cycle.