Caffeine

A brief history

The world is a big place and sometimes it feels like there really is nothing new under the Sun. Nowadays, information travel is instantaneous and nearly every event that has happened has been documented and is easily accessible. However, in the old days, it would take years for information to spread, leaving the door open for the same idea to be had in different spots of the world, without any connection. This is exactly how caffeine was first identified. 

The first recordings of deliberate caffeine consumption go as far back as 3000 BCE, when Chinese emperor Shennong accidentally discovered tea, noticing that certain leaves that fell into boiling water changed its properties. Coffee didn’t arrive onto the scene until the 15th century, when it was consumed in the Sufi monasteries of Yemen. But it wasn’t until 1819 that caffeine was isolated and understood. German chemist Friedlieb Ferdinand Runge was able to isolate pure caffeine, naming it “Kaffebase” (a base that exists in coffee).

Two years later, two separate sets of French chemists, Pierre Jean Robiquet and the pair of Pierre-Joseph Pelletier and Joseph Bienaime Caventou, were able to isolate caffeine as well. The funny thing is, all three sets of chemists were able to isolate caffeine without any knowledge of each other’s work. It’s like three people showing up to a birthday party with the same gift. In the end, Pelletier was the first to publish the term caffeine (caféine in French) in print. Later, in 1895, German chemist Hermann Emil Fischer was able to synthesize caffeine from its chemical components and derive the structural formula for the compound, leading to a Nobel Prize in 1902. And the rest is history. 

Body
Caffeine is a central nervous system and metabolic stimulant. That means that it triggers your body to boost alertness, focus and energy. After ingestion, it is completely absorbed by the stomach and small intestine within 45 minutes, after which it is distributed throughout your body tissues. The half-life of caffeine in healthy adults ranges from 3-4 hours.  

Mind 
In the brain, caffeine acts as an inhibitor to adenosine receptors, reducing their activity. This leads to an increase in dopamine activity, a neurotransmitter that accounts for the stimulatory effects of caffeine. Caffeine can also lead to an increase in epinephrine/adrenaline and serotonin, causing positive changes in mood. 

Tolerance
Over time, frequent caffeine consumption leads to an adaptation in which the body substantially increases the number of adenosine receptors in the central nervous system to account for the caffeine’s inhibitory effects. This causes the body to become much more sensitive to adenosine, leading to a reduction in stimulatory effects of caffeine, known as tolerance adaptation. It also means that a reduction in caffeine will increase the psychological effects of adenosine, bringing about withdrawal symptoms.  

Withdrawal
Adenosine regulates blood pressure through vasodilation, so an increase in adenosine causes the blood vessels to dilate. This is particularly affects the head, where excess blood flow leads to headache and nausea. Fatigue and drowsiness are also common. A reduction in serotonin from cutting caffeine leads to potential anxiety, irritability, inability to concentrate and diminished motivation to initiate or to complete daily tasks. In extreme cases it may cause mild depression. These effects generally begin 12 to 24 hours after discontinuation, lasting a few days and peaking on the second day. 

Addiction vs Dependency
Although not technically addictive, caffeine produces a wide range of withdrawal symptoms that can make it very difficult for some to quit, leading it to be referred as a dependency. Paired with the short term benefits that it provides, consumers can sometimes escalate their caffeine intake to dangerous levels and develop “caffeinism”, leading to a wide range of unpleasant physical and mental conditions including nervousness, irritability, anxiety, tremulousness, muscle twitching, insomnia, and heart palpitations. Caffeinism is only seen at levels of 1,000-1500mg of caffeine per day the equivalent of drinking 5 to 7 medium (16oz) coffees per day.

People generally begin to feel the affects of caffeine within an hour, with a mild dose wearing off in around 3 to 4 hours. Body size, natural tolerance, and frequency of use affect how much caffeine’s properties are observed in individuals. 

The primary source for caffeine, a plant alkaloid, is the coffee bean, which is the seed of the coffee plant. The arabica bean typically contains about half the caffeine of the robusta bean. Caffeine is also found in the beans, leaves, and fruit of over 60 plants, such as tea leaves and kola nuts, once used for sodas.