Like coffee, tea is a stimulating beverage. However, its invigorating effect is gentler and more sustained over time due to a lower caffeine content and a slower absorption rate.
Theine and caffeine are actually the same molecule. Discovered in 1827 by the chemist Oudry, the caffeine found in tea was initially called "theine" before being recognized in 1838 as identical to the caffeine found in coffee. Secreted by numerous plants as a defense mechanism against parasites, this alkaloid is present in about 60 plant substances, including coffee and tea, as well as cola, yerba mate, guarana, and cocoa.
Caffeine owes its stimulating properties to a molecular structure similar to adenosine, a neuromodulator that inhibits the release of certain excitatory neurotransmitters. By binding to various receptors in place of adenosine, caffeine impacts motor activity, the sleep/wake cycle, and alertness. In moderate doses, these effects are beneficial (physical and intellectual stimulation), but in high doses, they can be detrimental (nervousness, sleep disturbances).
In a 2017 study, researchers showed that in Europe, caffeine consumption is stable and falls below the recommendations of the EFSA (European Food Safety Authority), which suggests a limit of 3 mg per kg of body weight per day for children and adolescents, and 400 mg for adults. This intake primarily comes from coffee (40% to 94%), except in Ireland and the UK, where tea represents nearly 60% of caffeine intake.
No. While the caffeine in tea and coffee share the same molecular structure, they are not absorbed by the body in the same way. In tea, other molecules -specifically tannins and L-theanine- bind to the caffeine and delay its assimilation in the digestive tract.
As a result, it is released gradually into the bloodstream and the brain, acting progressively over a longer period. This stands in stark contrast to the caffeine in coffee, which enters the bloodstream rapidly and abruptly, providing an immediate "jolt" or "kick."
The "color" of a tea is often an unreliable indicator of caffeine content, which varies greatly depending on the origin, cultivation method, and level of oxidation. However, generally speaking:
By way of comparison, for the same volume of beverage, coffee displays significantly higher caffeine levels: from 120 mg (Arabica) to 230 mg (Robusta).
These average figures should be taken with a grain of salt, as caffeine content also depends on the tea variety, its origin, the specific parts of the plant used, and its processing (oxidation). According to research published in 2007, it also varies based on water temperature and steeping time: the hotter the water and the shorter the infusion time, the higher the caffeine content.
Because Matcha is a ground powder, you consume the entire leaf. This results in a higher caffeine content than other teas: approximately 126 mg per 1 teaspoon of tea whisked with 1/2 cup of water.
Derived from a South American tree different from the tea plant (Camellia sinensis), Mate actually contains less caffeine than tea, averaging about 30 mg per 10 fl oz cup.
No. Although sometimes called "Red Tea" due to its color, Rooibos is not a tea. It is a South African plant that is 100% caffeine-free, making it an herbal tea.
It is very easy to reduce the caffeine in your tea at home without ruining the flavor:
The 30-Second Rinse: Since caffeine is one of the first components released when leaves hit hot water, simply pour hot water over your leaves, wait 30 seconds, and discard that first infusion. This removes about 80% of the caffeine.
Cold Brewing: Infusing tea at room temperature or in the fridge results in a very low caffeine content.
Tip: Avoid "rinsing" a high-end Grand Cru or highly aromatic tea, as you may lose its delicate flavor profile.
Increase Steeping Time: If you steep tea for longer (more than 3 minutes), more tannins are released. While tannins make tea taste more astringent, they also slow down the body's absorption of caffeine.
The Second Steep: Use your tea leaves a second time. By the second cup, almost all the caffeine has already been extracted.
