I was drinking my coffee this morning, like every morning since I'm a caffeine addict, and I had a thought. Well, more than one. Anyways, my first thought was: why am I so addicted to coffee? I think it is worth an article so if you are a coffee lover, keep reading.
What is caffeine?
Caffeine is a central nervous system stimulant of the methylxanthine class. It is the world's most widely consumed psychoactive drug. Unlike many other psychoactive substances, it is legal and unregulated in nearly all parts of the world. There are several known mechanisms of action to explain the effects of caffeine. The most prominent is that it reversibly blocks the action of adenosine on its receptors and consequently prevents the onset of drowsiness induced by adenosine. Caffeine also stimulates certain portions of the autonomic nervous system.
Why are we addicted?
People can develop a dependence on coffee and other caffeinated beverages quite quickly. This is due to the chemical changes that sustained consumption produces in the brain. If someone drinks caffeine on a daily basis, he or she will develop a tolerance, just as one would to other drugs or alcohol. After a while, the user requires more and more caffeine to produce the same effects of alertness. Regular caffeine drinkers become acclimated to the wake-up aspect that the substance produces, and gradually require higher amounts to achieve the same “caffeine fix.” Similar to other drugs, people who abruptly stop drinking caffeine after prolonged use will start to suffer from withdrawal symptoms and experience cravings.
How Caffeine Affects the Brain
Caffeine is addictive because of the way that the drug affects the human brain and produces the alert feeling that people crave. Soon after caffeine is consumed, it’s absorbed through the small intestine and dissolved into the bloodstream. Because the chemical is both water- and fat-soluble, it’s able to penetrate the blood-brain barrier and enter the brain. Structurally, caffeine closely resembles a molecule that’s naturally present in the brain, called adenosine. Caffeine resembles the molecule so much so that it can fit neatly into the brain cells’ receptors for adenosine, and effectively block them off. Normally, the adenosine produced over time locks into these receptors and produces a feeling of tiredness. When caffeine molecules are blocking those receptors, they prevent this from occurring, and generate a sense of alertness and energy until the caffeine is metabolized. Additionally, some of the brain’s own natural stimulants are released, such as dopamine, and work more effectively when the adenosine receptors are blocked. The surplus of adenosine cues the adrenal glands to secrete adrenaline, another stimulant, and this further increases alertness and reduces feelings of tiredness. In people who drink caffeine regularly, the brain’s chemistry and physical characteristics actually change over time. The brain cells will begin to grow more adenosine receptors in an attempt to maintain equilibrium. This is how tolerance to caffeine develops; because the brain has more adenosine receptors, it takes more caffeine to block a significant proportion of them and achieve the same desired effect.
Caffeine and training
Caffeine is Very Effective. Studies have shown that caffeine can benefit endurance performance, high-intensity exercise and power sports. However, it seems to benefit trained athletes the most. The recommended dose varies by body weight, but is typically about 200–400 mg, taken 30–60 minutes before a workout.