With something as basic and necessary as sleep, it’s puzzling and troubling that so many people have problems with it.
Insomnia and other sleep disorders are prevalent: the American Sleep Association estimates that between fifty and seventy million American adults suffer from a sleep disorder. (1)
While many choose over-the-counter or pharmaceutical sleep aids, these come with a variety of side effects and other serious implications. Working with your body’s own chemistry may offer a more long-lasting and healthy alternative.
Drinking green tea before bed, on the other hand, is a natural solution to your sleep problems. L-theanine is an amino acid that is found in many plant species but in only two that we consume: medicinal mushrooms and tea. We mean true tea from the Camellia sinensis plant, not herbal teas made from herbs, spices, and other types of plants (e.g., rooibos).
When ingested, L-theanine is able to penetrate the blood-brain barrier to affect neurotransmitters.
L-theanine and the Brain
Firstly, L-theanine promotes mental alertness. (2) Its chemical structure is similar to that of glutamate, a stimulating neurotransmitter. Because of this, L-theanine readily binds to glutamate’s neuroreceptors and the effect in the brain is much the same as glutamate. This neurotransmitter modulates synaptic strength and speed. While binding to glutamate receptors, L-theanine blocks the transport of glutamate, further exciting cellular activity. (3)
Secondly, while stimulating neural activity, L-theanine reduces anxiety and stress by increasing serotonin, dopamine, and GABA (gamma-aminobutyric acid) hormones in the brain. (4) GABA is a hormone that is responsible for moderating feelings of fear or anxiety. Serotonin is an anxiolytic hormone (inhibits anxiety) that influences mood and is involved in the sleep process. Dopamine, on the other hand, is a hormone responsible for feelings of pleasure and well-being. Pharmaceuticals developed to treat anxiety and depression artificially block some hormones with promoting the production of these three.
Thirdly, L-theanine stimulates alpha brain waves to improve relaxation, reduce anxiety, and promote calmness. (5)
Lastly, L-theanine stimulates cognition and memory without raising blood pressure and stress. (6)
The Chemistry of Tea
Black, green, white, yellow, and oolong tea all contain L-theanine. These all come from the same plant but are processed differently to develop their flavor and caffeine content. The interaction between L-theanine and caffeine in tea is a synergistic marvel.
Caffeine alone, as found in coffee, can boost alertness and mental acuity but once it wears off, there’s often an energy crash. In tea, L-theanine and caffeine work together to enhance the performance of both while the neurostimulation of caffeine is balanced by calming hormones stimulated by L-theanine. (7)
Research into acute cognitive and mood effects of L-theanine and caffeine combined found better improved mental performance and decreased mental fatigue than with caffeine alone. (8) Essentially, you experience alertness without the caffeine crash.
“Tea has been shown to raise skin temperature to a higher level, to increase critical flicker fusion threshold, and to reduce physiological stress responses and increase relaxation ratings when compared with coffee or other control beverages matched for caffeine level,” writes the Journal of Nutrition. (9)
Drinking Green Tea Before Bed
In the context of sleep, L-theanine’s anti-anxiety and calming effects are what make it effective. Studies on the impact of this amino acid on sleep quality have shown it remarkably effective. L-theanine helps to induce deeper (hence, more restful) sleep so that you wake up more refreshed and less groggy. (10, 11) When in an already relaxed state, L-theanine enhances relaxation. (12)
Other Benefits of L-theanine
Here are a few more reasons to drink green tea before bed:
- It is readily bioavailable, retaining its molecular integrity at close to 100% by the time it reaches the small intestine. (13)
- Heals stomach ulcers by supporting antioxidant function. (14)
- Protective of the liver and promotes healing caused by alcohol damage. (15)
- Kills cancer cells and inhibits tumor growth; adds to the efficacy of chemotherapy agents. (16, 17)
- Reduces symptoms in people with schizophrenia. (18)
- Prevents stroke and cerebral hemorrhage. (19)
- Protects the central nervous system from oxidative damage, with implications for the prevention or reduction of neurodegenerative disease such as Huntington’s. (20)
How can you get L-theanine?
The best way to get L-theanine is through tea. Black tea contains it in greater amounts than green tea, Pu-erh tea, or white tea and matcha green tea has more than regular green tea. Matcha is green tea buds that are slowly acclimated to the shade shortly before harvest to boost the amino acid, chlorophyll, and antioxidant content. Instead of leaves, matcha comes in powder form. If you are sensitive to caffeine before bed, drink yellow or green tea before bed to make sure you get a restful sleep. Whatever tea you drink, steep for at least 7 minutes before drinking to release the highest amount of L-theanine. (21)
L-theanine is also available as a supplement and works for stress reduction and as a sleep aid. The problem with supplements is that they are often synthetic and there is no way to gauge their true potency. Dosage is therefore also difficult. Hence, you’re better off drinking tea. (22)