Caffeine is a drug belonging to a class of medicines called central nervous system (CNS) stimulants. It has the chemical formula C8H10N4O2, is soluble in water and in pure form appears as white crystals (1).
It is a natural product manufactured in the seeds, leaves or fruit of over sixty species of plants. It can also be synthesized artificially from uric acid.
An unusually bitter substance, caffeine is found in tea, coffee, chocolate and kola nuts; synthetically derived caffeine is also added to a variety of foods, soft drinks and medicines due of its ability to affect the body’s metabolism. Its bitter taste is usually disguised during the manufacturing process (2).
Most people take caffeine because it makes them more alert, lifts their spirits and offers a boost of energy. It is added to some pain killers because it enhances their effectiveness.
How Does Caffeine Work in the Body?
Adenosine molecules in the brain bind to receptor cells and settle down the central nervous system’s activity thus bringing on tiredness. Caffeine molecules look similar to adenosine and the brain can’t distinguish between the two. Hence, caffeine takes the place of adenosine molecules at the receptor cells, thus delaying fatigue (3).
Without the molecules that bring on fatigue, the levels of dopamine and glutamate (the body’s natural stimulants) increase, giving one an energy boost.
Caffeines Effects On The Central Nervous System
Roughly fifteen minutes after taking caffeine, the central nervous system is stimulated, with the most significant effect being enhanced alertness and decrease in sleep. Sustained, excessive consumption of caffeine can bring on a number of long and short term issues and side effects.
Experts believe that an average intake of 600 mg (approximately six cups of brewed coffee) can lead to side effects like insomnia, increased heartbeat, jitteriness, problems concentrating, muscle tremors, and nervousness.
Furthermore, caffeine elevates acid release in the digestive system, which may result in an upset stomach or heartburn and being a diuretic it increases the need to urinate leading to dehydration in severe cases. Once consumed, caffeine stays in the body for roughly six hours.
When adenosine is repeatedly blocked from taking its place on the receptor cells, the body automatically just builds more receptors. This means greater quantity of caffeine will be needed to plug the additional receptors and achieve the same degree of boost in alertness as before.
The increase in the amounts of caffeine will make kicking the habit more difficult. Besides blocking adenosine, it also enhances the levels of adrenaline in the blood and boosting mood in the same way as cocaine, only to a lesser degree.
Caffeine Withdrawal Symptoms
While people may make jokes about being irritable without their morning cup of coffee, some caffeine withdrawal symptoms are very real. In fact caffeine withdrawal is identified as a disorder according to studies carried out at Johns Hopkins Institute.
Research published in October 2004 issue of Psychopharmacology states caffeine withdrawal symptoms include problems concentrating, fatigue, headaches and even feelings of having flu accompanied with nausea and muscle aches (4).
Symptoms of withdrawal usually appear around 12 to 24 hours after stopping the consumption of caffeine and disappear after about one week. The symptoms are more severe for those used to ingesting large amounts of the substance (5).
- Mood swings
- Abnormal concentration
To minimize the effects, it is recommended to reduce the quantity of caffeine intake gradually over a period of several weeks. But, don’t eliminate it all together permanently, because coffee can improve cognitive brain health (make you smarter, physically and mentally), allowing you to do more of the things you love….but, better.
Plus, the health benefits of coffee completely over shadow any negative effects it may have, when consumed in moderation. So, don’t think you can go ahead and drink ten cups of coffee to get a caffeine kick, improve your ‘smartness’ and make you healthy! You’ll certainly get the kick, but this high amount of caffeine will be detrimental to your overall well being.
Stick to a couple of cups per day, or stay under your limit to see the benefits.