We are all familiar with the fact that tea contains theine and coffee contains caffeine. However, what many people don’t know is that theine and caffeine are actually the exact same substance. The different names have remained in use for over 200 years after the caffeine molecule was isolated, mainly to distinguish the source of the substance. The effect of caffeine, however, differs when drinking coffee compared to drinking tea.
The effect of caffeine
Caffeine (and therefore also theine) stimulates the nervous system by blocking the action of adenosine, an inhibitory neurotransmitter. As a result, more dopamine and serotonin are released, which improve mood. This allows caffeine to enhance alertness, mood, concentration, reaction time, and short-term memory.
All real tea – the tea that comes from the tea plant or the Camellia sinensis – contains caffeine. Compared to black tea, green tea generally contains less caffeine, though this can vary greatly. Tea plants grown at higher altitudes generally contain less caffeine. So if you compare a green tea grown at lower altitudes with a black tea grown at higher altitudes, the situation can be reversed.
Difference between theine and caffeine in coffee
In addition to caffeine, both green and black tea contain the amino acid L-theanine, which is not found in coffee. L-theanine can pass through the blood-brain barrier and promote the release of gamma-aminobutyric acid (GABA), an inhibitory neurotransmitter. This induces a state of relaxation without reducing alertness. Moreover, L-theanine stimulates the production of dopamine and serotonin, contributing to an improved mood. The amino acid also helps balance the effects of caffeine. In fact, the combination of L-theanine and caffeine appears to have a synergistic effect. Research shows that people who took both substances together were better able to focus than those who took only caffeine or L-theanine.
In general, green tea contains slightly more L-theanine than black tea, although the amounts can vary. For people looking for an energy boost without the jitters that coffee sometimes causes, both green and black tea are excellent alternatives.
Tea leaves in their raw form often contain more theine than coffee beans at the time they are picked. However, after processing, this balance shifts significantly. When coffee beans are roasted, the caffeine content increases significantly, so a cup of coffee can end up containing up to three times as much caffeine as tea.
Coffee is known for its strong energy boost, but this effect is often short-lived. After about 1 to 2 hours, the energy wanes. Tea, on the other hand, provides a more subtle yet longer-lasting energy. This effect can last up to 6 hours. The difference lies in L-theanine, an amino acid unique to tea. Together with the theine, L-theanine provides a gradual stimulation of the nervous system. This not only delivers a prolonged energy boost but also a calming effect, allowing you to feel relaxed while maintaining a high level of concentration.
While coffee provides a quick and powerful energy spike that fades rapidly, tea offers a balanced combination of energy and relaxation, ideal for sustained focus and alertness without the familiar restlessness that coffee can sometimes cause.
Sources:
https://www.nature.com/articles/1602489
https://pubmed.ncbi.nlm.nih.gov/20492310/
https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1467-3010.2007.00665.x
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2748160/
https://pubmed.ncbi.nlm.nih.gov/1356551/https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4728665/
https://pubmed.ncbi.nlm.nih.gov/18296328/