For modern humans, the morning cup of coffee or afternoon energy drink seems like a part of the very fabric of society. But what’s the real deal with caffeine? Is caffeine good for you? Bad for you? Both?
What is caffeine?
Caffeine is an all-around defence mechanism for the plants which produce it. For one thing, it’s a natural insecticide which does a good job of paralysing and killing off nasty pests which could threaten the plant.1
Caffeine is also a great weapon against other plants. The soil around coffee seedlings becomes saturated with caffeine, which inhibits other nearby seedlings from germinating.2 This basically guarantees that the most caffeine-rich coffee seedlings are the ones which manage to survive and claim a particular patch of land.
This wonder substance is found in a variety of different plant sources including, of course, coffee beans, cocoa beans, tea leaves, kola nuts and guarana berries.
How does it affect people?
Caffeine works by interrupting natural processes in your brain chemistry which result in you becoming tired and sluggish. There’s a specific molecule called adenosine which builds up in the central nervous system throughout the day and which binds to special adenosine receptors. This ultimately results in feelings of tiredness.
What caffeine does is to block adenosine from binding to the adenosine receptors3, thereby increasing alertness. The absence of the adenosine causes neurons to fire faster, and the process also stimulates the release of dopamine and adrenaline.
In other words, it gives you a boost.
Benefits of caffeine
We all know that caffeine makes you feel more energetic. The benefits don’t end there, however:
1. Caffeine can boost your athletic performance
Research has shown that caffeine has the potential to seriously increase overall athletic performance. One 2001 study4 found that taking caffeine allowed athletes to train with greater intensity, for longer, while experiencing less fatigue as a result.
Other studies found5 that caffeine significantly reduced post-workout aches and pains over the course of several days. Further research found6 that taking caffeine before heading to the gym significantly increased the ability of the test subjects to perform intense strength exercises.
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2. Caffeine improves your mood and boosts mental function
Don’t be fooled into thinking that the benefits of caffeine are all physical, however. Some research has connected caffeine with positive mood outcomes, including a reduced risk of depression7.
This is perhaps not so surprising given the fact that, as mentioned earlier on, caffeine causes a spike in dopamine production. Low dopamine levels have been linked with depression.8 Another 2014 study linked caffeine consumption with improvements in long-term memory.9 Despite these positive studies, more research is needed in this area.
3. Caffeine may protect against disorders like Alzheimer’s disease
Caffeine consumption has been consistently linked to positive health outcomes for a range of mental disorders, including Alzheimer’s disease however more research is needed. Caffeine appears to reduce inflammation in the brain10 and prevents the accumulation of the “tau” protein, both of which are closely linked with Alzheimer’s.11
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Disadvantages of caffeine
Unfortunately, every silver lining has its cloud. Here are some of the less savoury aspects of caffeine:
1. Caffeine boosts cortisol, makes you stressed and anxious
Caffeine is known to significantly boost12 the levels of the hormone cortisol in the body. Cortisol is one of the primary stress hormones and elevated cortisol levels have long been associated with heightened anxiety.13
This probably comes as no surprise to anyone who’s ever over-indulged in caffeine. Caffeine-induced “shakes” and “butterflies” are notorious.
2. Caffeine is highly addictive
When all is said and done, caffeine is a drug and caffeine addiction can become a very real issue to those who suffer from it.
The more caffeine you consume regularly, the more likely you are to become seriously addicted. The addiction requires you to consume ever greater levels of caffeine to feel and function “normally” and if you’re forced to go without, withdrawal symptoms can set in.
Symptoms of caffeine withdrawal include:
- Extreme tiredness
- Muscle cramps
- Lack of focus
3. Heavy caffeine use increases the risk of bone fractures
This may be linked to the elevated cortisol levels, as cortisol is also known to reduce bone density14 and strength, but whatever the cause, a 2012 meta-analysis15 found that caffeine increased the overall risk of bone fractures. This risk was dose dependent, meaning that the more you drink, the more at risk you are.