L-Theanine (γ-glutamylethylamide) is a unique amino acid that is not derived from protein sources like many other amino acids. It’s a non-protein amino acid found in green tea (Camellia Sinesis), a widely consumed beverage associated with positive health benefits. The structure of L-Theanine resembles that of L-glutamic acid, which is a precursor of the main endogenous antioxidant glutathione. The primary amino acid in green tea accounts for 1% to 2% of the leaf dry weight. L-Theanine supplements are generally available in the form of tablets or capsules in doses between 50 and 200 mg. L-Theanine is a transparent, colourless, odourless, water-soluble white crystalline powder.

 

Theanine is biosynthesized in tea plants with the amino acid alanine present in high amounts in the root, with the enzyme alanine decarboxylate, and produces ethylamine mostly found in leaves. Another free amino acid glutamic acid mainly found in stem reacts with ethylamine to produce theanine. Leaves of the tea plant are the storehouse of theanine although roots are the source of the free non-essential amino acid theanine.

 

Theanine occurs as isomers of L and D form. L-Theanine is the most readily absorbable form of Theanine. D-Theanine’s biological effects are unknown as not many studies have been carried out.

 

ZENITH NUTRITION L-THEANINE

Zenith Nutrition L-Theanine is a vegetarian dietary supplement that provides 100mg of L-Theanine per serving of the supplement. The supplement is manufactured in a GMP-certified unit and has gone through stringent testing for assurance on purity and potency. The supplement does not contain sugar, preservatives, corn, soy, dairy, yeast and gluten.

 

L-THEANINE HELPS REDUCE ANXIETY

L-Theanine promotes hypotensive effect by blocking the binding between L-glutamic acid and glutamate receptors in the brain.

L-Theanine reduces anxiety and attenuates rise in blood pressure at times of high-stress response.

L-Theanine produces hypotensive effects by regulating the peripheral nerves and vascular system.

L-Theanine supports good levels of dopamine and GABA in the brain to promote a relaxation-like effect.

 

L-THEANINE BOOSTS COGNITIVE HEALTH

L-Theanine boosts brain function by increasing the concentration of brain neurotransmitters such as dopamine, GABA, 5-hydroxytryptamine (5-TH), and glycine.

L-Theanine stimulates the expression level of nerve growth factor (NGF) and hippocampus.

L-Theanine reverses abnormal levels of corticosterone and catecholamine in the brain and serum and promotes the maturity of nervus centralis which is beneficial in the development of brain function.

L-Theanine improves learning and memory ability by protecting from oxidative brainwaves.

L-Theanine helps increase levels of dopamine in the brain which promotes focus and feelings of happiness.

 

L-THEANINE HAS ANTI-FATIGUE, ANTI-DEPRESSION EFFECTS

L-Theanine is helpful to reduce physical and mental fatigue by raising the levels of dopamine and hepatic glycogen, and decreasing the concentrations of 5-HT and serum urea.

L-Theanine intake prevents stress-induced impairments of hippocampal potentiation and improves memory.

L-Theanine helps reduce heart rate and decreases salivary immunoglobulin A (s-IgA) responses to acute stress.

L-Theanine reduces fatigue by reducing heart rate and mediating attenuation of sympathetic nerve activation or suppressing the excitation of the cortical neurons.

L-Theanine decreases the activity of the sympathetic nervous system and significantly suppresses the increase in salivary alpha-amylase induced by anxiety.

L-Theanine supports alpha brain wave generation, which is associated with an awake, alert, and relaxed state. An increase in alpha waves in the cerebral cortex has been proposed as an index of increased relaxation and alert mind state.

 

L-THEANINE PROMOTES A POSITIVE MOOD

L-Theanine supports calming sensation and positive mood by significantly enhancing the amounts of the main inhibitory neurotransmitter in the brain called GABA.

L-Theanine benefits mood by regulating the activity of another inhibitory amino acid neurotransmitter, glutamate in the brain. L-Theanine binds to the same brain cell receptors and blocks them to glutamate’s effect. This mechanism helps protect from the stress-inducing effects of glutamate, and in turn induces calming, relaxing effect.

L-Theanine helps lower the stress hormones cortisol and corticosterone and avoid their negative impact on memory and mood.

L-Theanine can modulate the release of serotonin and dopamine to bring about calming effects.

 

L-THEANINE SUPPORTS HEALTHY IMMUNITY

L-Theanine can enhance serum immunoglobulin and alleviate and protect against inflammation and infections. L-Theanine not only helps reduce stress levels but by doing so, L-Theanine counteracts the harmful effects of stress by giving a boost to the immune cells to fight infection. L-Theanine supplementation helps improve the body’s immune system by enhancing T lymphocyte function, and by decreasing anti-inflammatory cytokines and interleukins. It helps regulate the secretion of central nervous system stress hormones.

 

L-THEANINE SUPPORTS SLEEP

L-Theanine does not literally induce sleep, it helps reduce anxiety and stress which are the root causes of sleeplessness or repeated wakefulness. L-Theanine does not act as a sedative but improves the quality of sleep by lowering anxiety and promoting relaxation. Studies have found L-Theanine to be a safe, effective, non-addictive that does not cause side effects commonly associated with prescription sleep medications. L-Theanine improves sleep efficiency, produces feelings of prolonged and restful sleep, and reduces fatigue upon rising by lowering anxiety. Normal sleep helps to maintain better brain function and results in better cognitive health. L-Theanine reduces chemicals in the brain that cause anxiety and increase levels of calming brain chemicals that promote relaxation and can help with sleep.

 

L-THEANINE HAS ANTIOXIDANT & ANTI-INFLAMMATORY ACTIVITY

Mental stress can particularly increase your brain’s free radical load. L-Theanine protects the neuronal cells from damage through its antioxidant activity that keeps normal cellular levels of GSH.

L-Theanine helps improve brain function by inhibiting different neurological functions like catalase, superoxide dismutase, and succinate dehydrogenase.

 

WHY SHOULD ONE SUPPLEMENT WITH L-THEANINE?

Although theanine is present in most green teas, the amount present is unpredictable. Supplemental form of L-Theanine is a potential health-beneficial supplement and a cost-effective way to get an adequate dose of the active ingredient in green tea.

 

AFTER HOW MANY MINUTES OF SUPPLEMENTATION CAN WE FIND EFFECT?

L-Theanine when consumed gets metabolized in the body into glutamate and ethylamine, it crosses the blood-brain barrier. A relaxing effect is usually noted when L-Theanine is taken at doses 100mg-200mg within 30 to 40 minutes after L-Theanine is taken and lasts for 8 to 10 hours.

 

DOES L-THEANINE PRODUCE ANY SIDE EFFECTS?

L-Theanine has an effect on blood pressure, it may help lower blood pressure and hence should be avoided by people with low blood pressure.

People taking pharmaceutical medication are advised to consult a healthcare professional before taking supplements.

Pregnant and breastfeeding women should be particularly cautious and must take physician’s advice before planning to take supplements.

 

DOES L-THEANINE CAUSE DROWSINESS?

L-Theanine does not cause drowsiness or act as a sedative. Unlike the anti-anxiety drugs, L-Theanine does not result in increased drowsiness, slowed reflexes, or impaired concentration, L-Theanine promotes calmness without causing jittery feelings. L-Theanine supplements do not cause a risk of tolerance or develop dependence. Produces anti-anxiety and relaxing effects without producing sleepiness. L-Theanine does not cause daytime drowsiness but can be used for inducing sleep at any time of the day.

 

CAN THEANINE BE TAKEN IN CONJUNCTION WITH CAFFEINE?

The combination of L-Theanine and caffeine is found to benefit cognitively demanding tasks. The studies suggest that L-Theanine supports caffeine action, it enhances mental performance, task accuracy, alertness, reduces mental fatigue, and also modulates effects of increased blood pressure caused by a higher dose of caffeine. L-Theanine may help counteract some of the negative effects of caffeine.

The combination of L-Theanine and caffeine is proven by studies to improve both speed and accuracy of performance of the attention-switching task at 60 minutes and to reduce the susceptibility to distracting information in the memory task at about 60 min and 90 min, improves attention span, enhances ability to process visual formation.

 

WHEN SHOULD YOU TAKE L-THEANINE?

Since L-Theanine’s main role is to mitigate the negative impacts of stress on the body, L-Theanine supplementation can be majorly beneficial when taken during periods of high stress. When your body is under stress, there is increase in the production of stress hormones like cortisol and corticosterone. These hormones negatively impact brain function by inhibiting some brain activity, including memory, attention and learning ability. L-Theanine when taken during times of stress, works to lower stress hormones and avoid their interference with memory and learning.

L-Theanine supplement when taken before bed helps reduce sleep latency and promotes more restful sleep at night.

 

CAN L-THEANINE BE CONSUME AT DAY TIME?

Yes, L-Theanine can be consumed during day time. Adding L-Theanine to your daily routine can make notable difference to your day.

 

CAN YOU COMBINE L-THEANINE WITH GABA?

Yes, the research evidence suggests that L-Theanine when combined with GABA has a positive synergistic effect on sleep quality and sleep duration when compared to theanine or GABA alone. Activation of GABA receptors is attributed to the potential neuromodulatory properties of GABA, which seems to affect sleep behavior.

 

Reference:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6366437/

https://www.sciencedirect.com/science/article/pii/S2221169117308420

https://www.researchgate.net/publication/283753154_Health_Benefits_of_Theanine_in_Green_Tea_A_Review