We all know how important caffeine is in our lives. It’s the little pick-me-up we all need to get through the day. But have you ever wondered where this magical elixir came from?
Caffeine has been around since the dawn of time. It’s found in nature in many different forms, from coffee beans to tea leaves to chocolate. But it wasn’t until humans started drinking these beverages that we realized just how powerful this compound was.
Caffeine stimulates the brain and nervous system, enhancing wakefulness and concentration. Small doses can help us feel more alert and improve our focus. But too much caffeine can lead to jitters, anxiety, and even insomnia.
Come with us on this vivid journey to explore more of one of the most important substances in our daily lives.
The Evolution of Caffeine: How Plants Fight Back
Caffeine has a long and storied history, all the way back to 49 million years ago. That’s when plants first developed caffeine as a way to protect themselves from angry, hungry insects. It was an adaptation to the environment and one that’s served plants well ever since. The most popular plant that contains caffeine is coffee, but it’s by no means the only one. You can find it in all sorts of plants1.
Some plants in the tropics developed a new, deadly poison to protect themselves from harmful insects and rival plants. This poison is now known as caffeine – a natural pesticide that can be found all over the world. But don’t worry, it’s not deadly to humans. Unless you drink, like, a thousand cups of coffee. Then it might kill you2.
As it turns out, caffeine is a product of evolution. For millions of years, plants have been developing caffeine as a way to protect themselves. Scientists still don’t know exactly how or why plants make caffeine, but our huge appetite for it shows that they’re doing something right3.
While it might seem logical that coffee, tea, and cacao would be related since they all contain caffeine, a recent genome study shows that the genes that brew caffeine in coffee differ from those that make the compound in tea and cacao. In other words, these plants have been separated for a long time and have independently evolved the capacity to make caffeine3.
Caffeine is like a chemical vestige of the plant kingdom’s ancient past. It all started with a compound called xanthosine. Coffee plants have an enzyme that severs a dangling arm of atoms from xanthosine; then, a second enzyme adds a cluster of atoms at another spot. To finish things off, the plant uses two more enzymes to add two different groups. Voila! Xanthosine has been turned into caffeine. Caffeine and related xanthine alkaloids are found here and there throughout the plant kingdom2.
The caffeine evolution in coffee started when a gene for an N-methyltransferase mutated, changing how the enzyme behaved. This may not sound like much, but it was a big deal at the time. Later, the plants accidentally duplicated the mutated gene, creating new copies. Those copies then mutated into still other forms. What all this means is that coffee has undergone a lot of changes over the years2.
The origins of caffeine in coffee are murky, but we know it started with a single gene that mutated. This gene then duplicated itself and mutated again, creating different forms of caffeine. It’s like a game of telephone, where each generation changes the message slightly until it’s completely unrecognizable. In this case, the message is caffeine, and it’s gotten stronger and stronger over time2.
It’s pretty amazing how plants can adapt to their surroundings. They can synthesize compounds that help them survive in their ecological niches. And as we learn more about these compounds and their functions, we can see how different plant lineages have developed different ways to synthesize them. It’s all part of their natural adaptation to different ecological conditions3.
Caffeine Hits the Spot: How Plants Use It to Attract Pollinators
In order to protect themselves, many plants produce toxic compounds that make them unappetizing to would-be consumers. Caffeine is one such compound, and at high doses, it can be harmful to insects. As a result, insects have evolved taste receptors that help them avoid ingesting caffeine. At the same time, some plants make nectar with a small dose of caffeine to feed insects and other animals, so they’ll spread their pollen4.
Insects use their sense of taste to figure out which plants are the best to eat. Just like humans need to ensure we’re eating healthy, nutritious food, insects need to ensure they’re getting the same. However, some plants produce poisonous chemicals to keep insects away. These chemicals can be harmful to insects if they’re ingested. That’s why insects have special receptors that help them detect these poisonous chemicals, so they can avoid them and stay safe5.
Caffeine is bitter tasting to mammals and is toxic and repellent to honeybees at high concentrations. If bees can detect caffeine, they might learn to avoid flowers offering nectar containing it. Pollinators drive selection toward concentrations of caffeine that are not repellent but still pharmacologically active5.
Evidence suggests that these compounds can change pollinator behavior by making them better remember rewards. For example, honeybees given a little caffeine (which you can find naturally in coffee and citrus nectar) are three times more likely to remember a floral scent they’ve learned than bees just given sucrose4.
Two caffeine-producing plant genera, Citrus and Coffea, have large floral displays with solid scents and produce more fruits and seeds when pollinated by bees. Caffeine confers a selective advantage when these plants interact with pollinators. We might expect it to be commonly encountered in nectar4.
Data shows that plant-produced alkaloids like caffeine have a role in addition to defense: They can pharmacologically manipulate a pollinator’s behavior. When bees and other pollinators learn to associate a floral scent with food while foraging, they are more likely to visit flowers bearing the same scent signals. Such behavior increases their foraging efficiency while leading to more effective pollination. It’s like the plants are giving the pollinators a little nudge in the right direction. They’re giving them a boost of energy, like a caffeinated drink, to help them be more efficient in their work4.
The Journey of Caffeine: From Ethiopia to Germany.
Different cultures have been consuming caffeine for centuries without even knowing it! In the mid-19th century, a group of German scientists and philosophers finally discovered caffeine.
Ethiopians were the first to experiment with caffeine. They chewed the beans or ground them with fat to make a rudimentary energy bar. Later, they brewed the leaves with boiled water as a weak tea. It was in the 1400s that someone accidentally roasted the beans and discovered how good they smelled. They ground them and brewed a potent black beverage6.
Caffeine was fully understood as a substance in the middle of the 19th century. This event involved Johann Wolfgang von Goethe (1749 – 1832), one of Germany’s most influential writers and philosophers. They also dabbled in the realm of science. Goethe was a supervisor at the University of Jena and an active stimulator of scientific progress7.
In 1818, Friedlieb Ferdinand Runge (1794-1867) arrived in Jena and was soon introduced to Döbereiner. Runge told him about his experiences in isolating the active substances of some plants, and thus Döbereiner scheduled a meeting with Goethe and Runge on October 3rd, 1819. When they met, Goethe was very friendly and asked a lot of questions about Runge’s work7..
Goethe interviewed the young researcher and asked if he knew what was in the box. When the researcher said no, Goethe explained that a Greek researcher gave him unroasted coffee seeds as a uniqueness7..
Shortly after, in 1820, Runge isolated the energizing and pick-me-up chemical we now know as caffeine from coffee seeds and called it “Kaffein,” which later became “caffeine” in English. This term was included in the medical vocabulary in 1823. In 1826, Martius isolated guaranine from the guarana plant, and in 1827 Oudry found theine in tea. However, all of these proved to be the same chemical compound afterward7..
Ludwig Medicus (1847–1915) was a regular Joe who liked to put his feet up after a hard work day. In 1875, he proposed the structure of caffeine in his academic dissertation. He was ahead of his time and deduced the structure with the already-known pure compound. Nowadays, caffeine has been isolated from 60 other plants besides the better-known species7..
Callus cultures’ first reports of caffeine formation were back in the 20th century (Keller et al. 1971, 1972). Researchers took transects from coffee fruit to create primary cultures. After 4-5 weeks, 95-98% of the caffeine was present in the agar medium. Most likely, it diffused there8.
The Robusta genome was sequenced in 2014, and Arabica in 2017. Even though these two genomes offer coffee researcher hope, they still have a lot of research to do before they can create a better-tasting and healthier cup of coffee. The genes that produce desired flavors and aromas are the key to success; however, they still have to factor in weather and farming techniques. Who knows, maybe one day we can enjoy a cup of coffee that not only tastes great but is also good for us!9.
From Coffee Beans to Soft Drinks: The Many Forms of Caffeine
Did you know that there are over 60 plants that contain caffeine as an active ingredient? That’s a lot of coffee! Caffeine is found in leaves, seeds, or fruit of plants, and it’s consumed in beverages such as coffee, tea, chocolate, and soft drinks. Alternative names for caffeine include theine, guaranine, and mateine.
Coffee is the product that contains the highest and most variable quantity of caffeine in the human diet (between 0.8-1.8%). The amount of caffeine present in coffee depends on the coffee beans’ genetic makeup and the time and method of preparation. Generally, it oscillates between 30 and 175 mg per 150 ml. Decaffeinated coffee contains between 2 and 8 mg per 150 ml 10.
The caffeine contents of green coffees vary widely between the different Robusta and Arabica species, and even within each species, there is a wide range of values for caffeine contents (Ky et al. 2001; Silvarolla et al. 2004). Robusta coffee, in general, has higher caffeine content, with an overall mean value of 2.2 %, whereas that of Arabica is about 1.2 %, with a range of 0.6-1.9 % (Clarke and Macrae 1985; Franca et al. 2005; Belay et al. 2008; Belay 2010a). Intermediate values have also been reported for commercially less important species, such as Liberica with a mean value of 1.35 % and Arabusta with about 1.72 % (Clarke and Macrae 1985). The coffee paracoffea genus, available in Africa and Asia, has low caffeine contents of about 0.2 % (Clarke and Macrae 1985). 11.
Like many other foods we eat and drink, the composition of coffee is very complex – think of all the different ways you can order it! It depends on the species and varieties of the plants, how they are grown, and the methods used for picking and processing the fruit. Just as different combinations of ingredients can create very different flavors in your favorite recipes, these same factors which influence the overall quality and chemical composition of raw coffee beans creates regions with their own coffee ‘terroir.’ These include the location, altitude, and weather of the plantation, the soil composition, fertilization, and finally, the cultivation, harvesting, and drying methods used 11.
| Product | Volume / Weight | Mean Caffeine (mg) |
| Roasted Coffee | 100 ml | 41-83 (60) |
| Instant Coffee | 100 ml | 27-72 (50) |
| Starbucks Coffee | venti 20 fl. oz. | 415 |
| Black Tea | 100 ml | 10-46 (25) |
| Green Tea | 100 ml | 8-17 (12) |
| Lipton 100% Natural Lemon Iced Tea | 20 fl. oz. | 35 |
| Dark Chocolate | 100 g | 17-118 (68) |
| Milk Chocolate | 100 g | 1-38 (20) |
| Hot Chocolate | 100 ml | 1-49 (34) |
| Monster Energy | 16 fl. oz. | 160 |
| Red Bull | 8.4 fl. oz. | 80 |
| Coca Cola | 12 fl. oz. | 35 |
| Pepsi | 12 fl. oz. | 38 |
The Caffeine Conundrum: To Drink or Not to Drink?
Caffeine has been shown to increase resting brain activity, meaning it helps us process information more quickly and efficiently. Of course, like anything, too much of a good thing can be bad for you. If you consume large quantities of caffeine, it can lead to some unpleasant side effects like jitteriness, anxiety, and insomnia. So be careful not to overdo it, and enjoy that extra energy boost responsibly!7
Coffee is like a magic potion containing thousands of different chemical compounds. But the one it’s most famous for is caffeine – the most widely consumed pharmacologically active compound in the world. Although a lot of attention has been focused on caffeine, it’s important to remember that it’s not the only compound in coffee. Of course, coffee beans are seeds containing a wide range of macro- and micronutrients12.
When you drink caffeine, it’s like getting a bunch of excited, chatty toddlers in your brain. The adenosine receptors can’t handle all the stimulation, and it causes a bunch of neurotransmitters to be let loose. The main culprits are dopamine and glutamate, which get freed up and start stimulating and exciting everything they see. But it doesn’t stop there – adrenaline and serotonin get involved too, and before you know it, you’re feeling the euphoric jolt we all know and love13.
If you’re like most people, you’re probably familiar with the effects of caffeine. But did you know that it can also negatively affect your health? For example, large quantities of caffeine can cause various physiological and psychological effects, such as relaxation of bronchial muscles, stimulation of the central nervous system, gastric acid secretion, and diuresis. Moreover, sleeping habits, performance, and concentration are modified by caffeine7.
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