Nootropics exist in a variety of forms including pharmaceutical medications, such as methylphenidate (also known as Ritalin), to more accessible forms such as caffeine. Many nootropics are stimulants, which means they may have an undesirable “come-down” effect as they are cleared from the body. Natural or plant derived nootropics, such as L-theanine, however, are not known to cause negative side effects, thus may be preferable options for people seeking to use nootropics long term, or who do not wish to have rebound effects.

What is L-theanine?

L-theanine is a unique water-soluble amino acid, most commonly found in tea (Camellia sinensis).

Its most well-known effect is its ability to enhance both cognitive function and relaxation without inducing sedation. Thus, in many eastern traditions, holding tea ceremonies is a calming and meditative practice, despite the consumption of caffeine within the tea.

Tea leaves contain approximately 1-3% L-theanine, which largely depends on the geographic area in which the tea is produced, the production techniques, and the type and time of harvest. Therefore, when using L-theanine for therapeutic purposes, taking a supplement which contains a specific amount of L-theanine may be more effective than consuming tea.

Brainwaves  

Brainwaves are patterns of electrical activity generated by the brain depending on our cognitive state. There are 5 brainwave states which range from our sleeping, slow wave state to peak performance state.

• Gamma - High level cognitive processes. Peak performance state. Usually present in deep concentration.
• Beta - Our waking state. Listening, thinking, problem solving, processing information and other functional processes occur in this state. 
• Alpha - Calm effortless focus and an overall sense of relaxation. Ease in switching between tasks.
• Theta - The state between wakefulness and sleep. Drowsiness.
• Delta - A closed-eye unconscious state. Most likely to occur in slow wave, deep sleep.              

The alpha state may be favourable during periods where high mental performance is required, such as during exams, presentations or general work days, as it creates a calm, non-anxious, focused state.

Nootropic effects

L-theanine, and in particular, a purified L-theanine material called AlphaWave® has been shown to increase alpha wave activity within 3 hours of ingestion. A recent clinical study examined the efficacy of AlphaWave® in response to acute stress during the pandemic. During two study periods, separated by a seven-day washout interval, participants received either AlphaWave® or placebo and were subjected to a mental arithmetic test known to induce stress.

AlphaWave® significantly increased alpha power after three hours and decreased salivary cortisol compared to placebo. Therefore, a single dose of AlphaWave® improves physiological indicators of acute stress, particularly during a period marked by accentuated daily stressors.¹

Several clinical trials have found that L-theanine taken in conjunction with caffeine improved short-term sustained attention and overall cognition.^2-4 In the majority of trials, this combination enhances alertness and accuracy in attention-switching within the first two hours following administration, and decreases mental tiredness. In addition to this, L-theanine has been shown to counteract the stimulating effects of caffeine, thereby promoting a more sustained focus without the harmful effects typically associated with caffeine consumption alone.⁵

Other health benefits

L-theanine has a number of other health benefits asides from creating calm focus. It possesses antioxidant, anti-inflammatory, anti-cancer, cardiovascular protective, liver and kidney protective and immune regulatory effects.

Clinical trials also suggest that L-theanine may be supportive for sleep dysfunction, ADHD, Tourette’s syndrome, depression and immune function.

Speak to your natural health care practitioner to understand whether L-theanine is right for you.

References

1. Evans, M., McDonald, A. C., Xiong, L., Crowley, D. C., & Guthrie, N. (2021). A Randomized, Triple-Blind, Placebo-Controlled, Crossover Study to Investigate the Efficacy of a Single Dose of AlphaWave® L-Theanine on Stress in a Healthy Adult Population. Neurology and therapy, 10(2), 1061–1078. https://doi.org/10.1007/s40120-021-00284-x
2. Anas Sohail, A., Ortiz, F., Varghese, T., Fabara, S. P., Batth, A. S., Sandesara, D. P., Sabir, A., Khurana, M., Datta, S., & Patel, U. K. (2021). The Cognitive-Enhancing Outcomes of Caffeine and L-theanine: A Systematic Review. Cureus.
3. Mancini, E., Beglinger, C., Drewe, J., Zanchi, D., Lang, U. E., & Borgwardt, S. (2017). Green tea effects on cognition, mood and human brain function: A systematic review. In Phytomedicine (Vol. 34).
4. Camfield, D. A., Stough, C., Farrimond, J., & Scholey, A. B. (2014). Acute effects of tea constituents L-theanine, caffeine, and epigallocatechin gallate on cognitive function and mood: A systematic review and meta-analysis. Nutrition Reviews, 72(8).
5. Dodd, F. L., Kennedy, D. O., Riby, L. M., & Haskell-Ramsay, C. F. (2015). A double-blind, placebo-controlled study evaluating the effects of caffeine and L-theanine both alone and in combination on cerebral blood flow, cognition and mood. Psychopharmacology, 232(14), 2563–2576. https://doi.org/10.1007/s00213-015-3895-0