Can´t function... Need caffeine!

By Catherine Saxelby

If you’re having trouble falling asleep at night, check how much caffeine you’re drinking, suggests nutritionist Catherine Saxelby. It could be the culprit... How does caffeine affect you? How do you know when it’s too much? How much caffeine do you ingest? Three things to help you fall asleep

We all love the lift we get from a café latte or a can of energy drink. The caffeine they contain boosts our concentration, gives us ‘energy’ and overcomes the perception of fatigue – the three main reasons for its popularity in our fast-pace world.

Caffeine is a natural stimulant and is found, in varying amounts, in coffee, guarana, tea, cocoa and chocolate. It is also added as in ingredient to cola soft drinks and ‘energy’ drinks. These often claim they have ‘natural’ caffeine from guarana, a vine native to South America, implying that it’s somehow ‘better for you’.

In reality, there are around 60 plants that contain caffeine – it acts the same way and still adds to your total intake.  Tea leaves and coffee beans are ‘natural’ too but we can overdo the caffeine from them.

How does caffeine affect you?

Caffeine acts on the central nervous system, speeding up the heartbeat and rate of breathing, dilating blood vessels and relaxing smooth muscles. It helps you concentrate, overcomes tiredness and enhances physical performance in athletes.

Most people can handle 300 milligrams of caffeine (equivalent to four cups of instant coffee or two espresso coffees OR two energy drinks) a day with no health problems. 

Sensitivity to caffeine, however, varies enormously.  Some people find they’re ‘over-stimulated’ after just one cup, while others appear to be able to sip coffee all day long without any ill effect, especially if they’ve built up their tolerance to it.  However if you notice you have trouble sleeping or any of the other symptoms listed below, you’re probably drinking too much.  

During pregnancy, it’s wise to limit caffeine to 150–200 milligrams (one cappuccino or two instant coffees) a day. Earlier reports of caffeine causing low-birth-weight babies or miscarriage have not been supported at moderate levels, but may occur at high intakes.  

Back to Top

How do you know when it’s too much?

The six telltale signs
If you drink coffee all day, you can be overloading your system with caffeine without realising it.  Over time, if you’re a regular sipper, it’s easy to gradually build up a tolerance to caffeine, so you can take in large amounts without noticing problems. Here’s the 6 telltale signs that you could be drinking too much: 

1. Insomnia
2. Upset stomach or heartburn
3. Too-rapid heartbeats (tachycardia)
4. Nervousness
5. Irritability
   
6. Over-anxiety (‘coffee jitters’).

At high intakes, caffeine can act as a mild diuretic, which means it triggers more frequent urination which can lead to dehydration, a concern in hot weather.

Back to Top

How much caffeine do you ingest?

Caffeine is found in coffee, energy drinks, tea, cocoa and chocolate. The table below provides an approximate guide to the amount of caffeine found in beverages and chocolate.

The most concentrated sources are coffee and energy drinks so these are the first two to cut back on if you can’t sleep.

Figures give average values only. There is a lot of variation between brands and types of drinks.

Caffeine concentration varies with the type of coffee beans or tea leaves and the strength of the brew – the stronger the coffee or tea, the more caffeine you drink.

Back to Top

Three things to help you fall asleep

1. Try to halve the amount of caffeine you drink overall - limit your intake to a maximum of two espresso coffees OR two energy drinks OR three to four instant coffees OR a combination such as one espresso plus two instant coffees.
2. After 4pm, stop drinking any caffeinated drinks as caffeine can take three to seven hours to clear through your system. Instead, switch to decaf coffee or tea, coffee substitute (made from roasted barley, chicory or dandelion root), herbal teas (peppermint or lemon with ginger are pleasant and refreshing) or rooibos (red tea) which are caffeine-free. Note: green tea contains caffeine even though it’s often enjoyed as a herbal tea.
3. Before bed, sip a mug of hot milk with a little honey or try one of the 'sleepy time' herbal tea blends - these contain chamomile, valerian, lemon balm, passionflower, hops, skullcap or other sedating herbs which are believed to induce sleepiness and rest.

Back to Top