Blog post by Gluco Ambassador, Dave Gibson
The most commonly used drug in the world is caffeine, present in tea, soft drinks, some chocolate and of course, coffee. With the clocks changing, we’re sure to crave more of the stuff to get us through the shortened, darker days.
But what are the effects of caffeine? How much is too much? Sleep expert and nutritionist, Dave Gibson shares his thoughts and tips on how to easily reset your relationship with caffeine, to enjoy it and avoid it affecting the quality of your sleep.
Caffeine – the facts…
One of the mind-boggling stats from the British Coffee Association is that we drink roughly 55 million cups of coffee in the UK, and two billion cups of coffee worldwide every day. This worldwide consumption is 100,000 metric tonnes in weight or equivalent to 14 Eiffel towers.
Typically, caffeine in the form of coffee (and tea) is drunk in the morning and throughout the day to give us a ‘boost’ or a ‘pick me up’ and to ‘get us going’ which makes caffeine the most widely consumed psychoactive substance on the planet.3
The caffeine effect…
Part of caffeine’s attraction is that it gets into our body quite quickly and takes about 15 to 20 minutes to hit the brain. After about 45 minutes 99% has got into the blood stream and then half of it gets eliminated within four to six hours, meaning that most of us get the urge for another shot. However, our sensitivity to caffeine is genetically determined and caffeine can have a slightly different effect on our body because of this, with about 10% of the population being able to drink caffeine late at night and still get to sleep.4
When you understand how caffeine affects the body, it’s easy to see why it is so incredibly addictive.
It keeps you awake: There are 2 things that are needed to induce sleep, the desire for sleep and the need for sleep. The desire for sleep comes from Melatonin production (the sleep hormone based on night and day). While the need for sleep comes when the brain produces chemicals in response to the number of hours we have been awake. Caffeine blocks this process. When we should feel tired, caffeine literally sits in brains sleep receptors to block their activity, and therefore keeps us awake when we otherwise expect to feel tired.
It makes you feel good: Caffeine also enhances our mood. It lifts us by increasing the effect of ‘Dopamine’ which is a neurotransmitter that is commonly associated with the ‘pleasure system’ of the brain. By increasing Dopamine activity in the brain, caffeine’s effects are in fact like those of stimulant drugs (amphetamine and methylphenidate) which makes it highly addictive.5,
It pumps you up, mentally and physically: Caffeine gives us a decent boost with many relying on it to beat the afternoon lull, super charge training sessions or gee up after a bad night’s sleep. Caffeine stimulates the brain to increase the release of hormones which then direct the body to produce Adrenaline and Cortisol – the stress hormones, activating our ‘fight or flight response’ boosting and diverting energy to muscles, increasing our heart rate and generally revving the body up to increase performance and mental alertness. At its peak rate of release in the morning Cortisol helps us to wake up by boosting our energy and increasing our appetite. When we have a coffee first thing in the morning we are ‘super-boosting’ our cortisol levels, only to have them fall later, when we have the urge to have another fix of coffee.
“But what goes up, must come down….”
There are significant downsides of over use of caffeine in the long term:
- It affects your immune system: Chronic elevations of Cortisol can alter the immune system responses
- It exhausts adrenal glands Which leaves us with energy depletion. The effects if adrenalin can also cause muscle twitching and even a fast heart rate
- It affects quality and quantity of sleep Consumption of caffeine late in the day is well known for its effect on sleep. Insomniacs and those who are hypersensitive to caffeine (i.e. get the jitters after on cup) should give up caffeine altogether
- It affects our ability to absorb some essential nutrients Long term caffeine consumption effects Vitamin D and calcium absorption along with Iron
- It effects your mood and mental faculties Long term overuse of caffeine has been associated with depression, mood sensitivity, increases in anxiety, restlessness and memory fatigue
So how much can, and should we drink per day?
In controlled doses caffeine as a stimulant for either everyday life or as a performance enhancer is fine, just as professional athletes do. There is no one set response to caffeine. The way one person responds to it will be completely different to another. The problem comes when we go above the recommended 300 – 400 milligram a day suggested maximum intake which is about 3 small cups of coffee, 7 -8 cups of black tea, or two 16fl.oz energy drinks.
Five steps to reset your relationship with caffeine.
- Know what you are drinking: Oddly enough, the stronger, darker coffee roasts have lower caffeine content, with the way the beans are roasted and their brewing time will also affect caffeine levels. As a general rule
- A cup of coffee has about 80mg
- A mug of coffee has about 150mg
- A mug of tea has about 50mg
- A 12oz can of soda has about 50-60mg
- Take it in a single dose taken once a day, ideally, in the morning when you want to be most alert
- But don’t make it the first drink of the day. You wake dehydrated, so drink at least 1 large glass of water on waking. Then take your first caffeine hit at least one hour after waking up. Your body has a normal boost of cortisol first thing, so you don’t need to over-stimulate yourself too early. Instead get light into your home first thing, by opening all the curtains and get outside to naturally boost cortisol levels through exposure to sunlight.
- Set a caffeine curfew – after lunch, especially if you are sensitive to it. 2pm is a good time.
- If you need an afternoon boost, choose something caffeine free like natural glucose. Gluco tabs or juice are a great tasting and satisfying option. Glucose is nature’s natural form of energy, and is often called ‘Blood Sugar’ as it circulates in our blood as our internal source of energy. Our bodies process most of the carbohydrates we eat into glucose, which either gives us an immediate boost, or gets stored in muscle cells or the liver (as glycogen) for later. The trick when using Glucose as a boost is to use just the right amount to give ourselves a boost without taking in and storing extra ‘carb calories’ – these are better supplied within our main meals as part of complex carbohydrates, which also contain fiber.
Those who should avoid caffeine all together
It is taken as read that insomniacs should avoid caffeine intake completely until they have solved their sleep problems. As excessive caffeine intake during pregnancy has been linked to premature delivery, miscarriage and low birth weight, pregnant women should strictly limit or avoid caffeine-containing drinks, food and drugs. People with high blood pressure, Kidney or Liver disease, anxiety or depression and GORD (Gastroesophageal reflux disease) should also avoid caffeine.
If you stop drinking coffee quickly, it can lead to symptoms of withdrawal, including headaches and irritability. These typically start within a day and last for between five to seven days. If you want to avoid this you can cut back gradually, or alternate with decaf coffee.
The charts below show typical caffeine content in popular beverages. Drink sizes are in fluid ounces (oz.) and milliliters (mL). Caffeine is shown in milligrams (mg).
|Coffee drinks||Size in oz. (mL)||Caffeine (mg)|
|Brewed, decaf||8 (237)||2-5|
|Espresso, decaf||1 (30)||0|
|Instant, decaf||8 (237)||2|
|Latte or mocha||8 (237)||63-126|
|Teas||Size in oz. (mL)||Caffeine (mg)|
|Brewed black||8 (237)||25-48|
|Brewed black, decaf||8 (237)||2-5|
|Brewed green||8 (237)||25-29|
|Ready-to-drink, bottled||8 (237)||5-40|