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Coffee is the most consumed of all beverages in the world (I know what you are thinking; it’s not alcohol!).
And, we all know that caffeine is one of the main reason for our drinking coffee. Although caffeine is contained in foods as well, more often than not we turn to caffeine beverages (coffee, tea and energy drinks) for our daily dose of caffeine.
So, what is it about caffeine that endears it so much to us all? Well, let’s find out! But, before we go into the nitty-gritty of what makes caffeine ‘special’, let us have a look at what caffeine is and indeed, what caffeine does to our minds and bodies.
What is caffeine?
Chemically speaking, caffeine is 1,3,7-trimethylxanthine.
Once we sip it in, caffeine gets absorbed through our gastrointestinal tracts (stomach and intestines) within a matter of minutes. After absorption, it moves rapidly through cell membranes and tissues, exerting its action. Even the blood brain barrier isn't able to stop caffeine; caffeine, thus effortlessly enters our brain tissue and exerts a prominent action there.
According to some estimates, caffeine starts appearing in our blood within 15 minutes of drinking coffee; the highest blood concentrations are reached in about 45 minutes. And, caffeine carries on working its magic for another 3-6 hours.
Pharmacologically, caffeine is an adenosine receptor antagonist. Adenosine is a chemical that depresses the release of excitatory neurotransmitters – noradrenaline, dopamine, serotonin, acetylcholine, glutamine and GABA. This action is mediated through the stimulation of adenosine receptors.
Blockage of the adenosine receptors by caffeine, therefore, leads to increased release of the above mentioned excitatory neurotransmitters. Caffeine can therefore be said to possess a central nervous system stimulant action.
What does caffeine do to our minds and bodies?
Here are some wonderful things – discussed in detail – that caffeine can do for you:
- Elevates mood: The effects of caffeine on mood have been extensively studies in humans. There is evidence to suggest that lower doses of caffeine (20-200 mg) may have a positive effect on mood. ‘Energetic’, ‘imaginative’, ‘confident’ and ‘alert’ are some of the terms that coffee drinkers use to describe the effects of caffeine. Additionally, improved motivation and enhanced ability to concentrate are also reported. An interesting observation is that caffeine – owing to its mood elevating abilities – has the potential to reduce the severity of depression and the risk of suicide.
- Reduces sleepiness and improves alertness and information processing: Not only does caffeine elevate mood but it can also reduce sleepiness – even when used in a doses as little as 50 mg per day. Caffeine is apparently believed to cause increase in the rate of cerebral metabolism. Regular coffee consumers report ‘better workplace performance’ and reduced reaction times. Likewise, caffeine improves self-esteem, confidence and socializing as well. Furthermore, anecdotal evidence suggests that coffee drinking works when students use it during times of examination. Similarly, usefulness of caffeine when used by elite forces – for producing wakefulness and alertness – has also been proven.
- Improves sports performance: It has long been suspected that caffeine, when taken in low-moderate doses, improves sports performance especially in trained athletes. Caffeine is of benefit in extended, exhaustive exercise situations like ultra-endurance events and in high-intensity exercises such as sprints associated with football and rugby. Furthermore, in a very interesting finding, Stuart et. al. reported that caffeine improved skill levels (ball control) of athletes under match conditions as well as in training (Stuart et al., 2005). Enhanced mental focus, reduced reaction times, improved lean muscles mass (as discussed in the subsequent section), and efficient utilization of energy substrates are some of the mechanisms thought to be responsible for caffeine’s performance-enhancing abilities. Apparently, caffeine is so efficient that four cups of ‘pre-match’ black coffee has almost become a norm in all elite level soccer tournaments.
- Suppresses appetite and induces weight-loss: Like most central nervous system stimulants, caffeine too suppresses appetite and reduces daily calorie intake. Although, how it does so is not known, caffeine seems to be as effective as amphetamines in causing appetite suppression . Interestingly, rather than reducing the portion size of individual meals, caffeine has been shown to reduce meal frequency. Another aspect of caffeine’s weight-reducing effect – or better yet, its ‘body composition’ improving effect – is its ability to alter substrate use. Whereas normally, the body relies on use of carbohydrate for producing energy, consumption of coffee shifts the balance in favor of fats. Utilization of fatty acids over carbs, especially when exercising leads to loss of body fat. Thus, decreased reliance on glycogen breakdown and increased dependence on fatty acid metabolism to provide energy to the exercising muscles is responsible for improved body composition.
A combined result of suppression of appetite and preferential burning of fat over carbs is what makes caffeine a much sought-after ingredient in most ‘fat-loss’ or ‘ergogenic’ formulations.
- Produces analgesia: Caffeine produces a mild analgesic effect. In combination with its mood-elevating effects, caffeine may prove to be quite an effective pain-killer. Caffeine is commercially available in combination with acetaminophen (paracetamol); this boosts the efficacy of either drug to produce profound analgesia.