The 8+ Benefits of Theanine

The Benefits and Mechanisms of Theanine

Theanine has many benefits that protect the brain and heart, reduce stress, and improve mood. R

 
 

Basics

 
L-Theanine or 5-N-Ethyl-Glutamine

L-Theanine or 5-N-Ethyl-Glutamine

 

Theanine is a non essential amino acid. R

The biological activity of L-theanine is very high in vivo. R

L-theanine is an important bioactive component of tea, and has many physiological functions:

  • regulating immune response R R
  • preventing diseases R
  • anti-tumor R
  • relaxing neural tension R
  • anti-oxidation stress R

Regular brewed black tea contains significantly more L-theanine per cup when compared to commercially available green tea. R

There are a few different sources and forms of theanine:

  • From green tea and fungi such as tea leaves, Japanese Camellia Bay, and Bolster mushrooms R R R
  • I-L-theanine (L-theanine) 
  • D-theanine (competes for absorption) 
  • Suntheanine (manufactured from of L-theanine) 

In The Body

 
 
  • Theanine is absorbed in the small intestine after oral ingestion. R
  • Its hydrolysis is to L-glutamate and ethylamine occurs in both the intestine and liver.  R
  • It can also cross the blood–brain barrier intact, and register pharmacological effects directly. R
  • Theanine reaches the brain within an hour remains elevated for up to 5 hours.
  • Theanine promotes alpha-wave production in the brain. R

Mechanisms of Action

 
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  • L-theanine inhibits binding of glutamate to its cortical excitatory neuronal receptors: AMPA, kainate, and NMDA. R
  • The inhibition of glutamate receptor activity is thought to contribute to the anti-stress effects of L-theanine. R R

Benefits

1. Improves Cognitive Function and Mood

 
 

Theanine increases serotonin, dopamine, GABA, and glycine levels in various areas of the brain, as well as BDNF and NGF levels in certain brain areas. R R R R

In combination with caffeine, L-theanine has shown to improve memory and increase attention. R R

L-theanine improved task switching. R

L-theanine and green tea extract helped adults with mild cognitive impairment perform better on memory recognition tests. R

L-theanine with caffeine improves mood within 60 minutes. R

2. Reduces Stress, Anxiety, and Schizophrenic Symptoms

Stress symptoms and heart rates were reduced with L-theanine supplementation. R

Supplementing 400mg of L-theanine for 8 weeks reduced schizophrenic symptoms, anxiety and muscle pains in patients. R

Compared to Xanax, L-theanine was able to promote relaxation in healthy subjects. R

3. Supports The Heart

 
 

In European subjects, 3 cups of tea a day was able to reduce the rate of heart attacks by 11%. R

On Japanese subjects, stroke and heart disease were reduced by green, black, and oolong tea consumption, compared to coffee drinkers. R

L-theanine lowers blood pressure. R

4. Increases Sleep Quality  

 
 

Doses of 200mg of L-Theanine twice a day for 6 weeks improved the quality of sleep of ADHD boys. Supplementation also helped decrease sleep onset and increase sleep percentages. R

5. Has Antioxidant Properties 

In certain doses, L-theanine from green tea has antioxidant properties. R 

L-theanine through antioxidant and anti-inflammatory actions reduced bladder hyperactivity. R

L-theanine protected against liver toxicity from alcohol. R

By inhibiting NF-κB and TGF-β, L-theanine was able to prevent liver fibrosis. R

L-theanine is able to decrease oxidative damage and stopped inflammation. R

6. Has Antihistamine Properties

Histamine release from mast cells was decreased with the treatment of theanine and might possess mast cell-stabilizing capabilities. R

Theanine inhibited mast cell mediated anaphylactic reactions. R

7. Improves Immune Function

In humans, ingestion of L-theanine by drinking tea induces innate immune response and immunologic memory. R

In rats, administration of 400 mg/kg BWL-theanine improved immune function by R

  • increasing the splenic weight
  • altering the TH1/TH2 balance
  • decreasing the corticosterone levels
  • elevating dopamine and serotonin in the brain
  • regulating the mRNA expression of PLC isomers in the heart

8. Neuroprotective

L-theanine provided neuroprotection against Parkinson-related neurotoxicants. R

It may be useful for preventing PD symptoms. R

My Experience

 
 

I originally supplemented with l-theanine because I had high levels of TGF-beta 1. 

With L-theanine my blood pressure was reduced and I also had a calm but alert sense of focus and clarity.  I take it on an empty stomach, in the morning and evening. 

Where to Get Theanine

 
 

I prefer not to get theanine from tea, since tea is high in tannins. 

I use Suntheanine from Doctor's Best.  

When I make Super Coffee, I use the pure powder.

Doses are health and age-dependent. R  

According to research from the University of Newcastle in Australia, the best way to get L-theanine from tea: R

  1. Steep tea at 80 degrees Celsius for 30 minutes
  2. Use water to tea ratio of 20 ml per 1 gram
  3. Steep tea that is between 0.5 and 1 mm in particle size

Side Effects

 
 

L-theanine can cause headaches and digestive discomfort. R

It can also reduce the effects of stimulants. R

More Research

  • Promotes anti-inflammatory IL 10. R
  • Can prevent hepatotoxicity from doxorubicin. R 
  • May inhibit glutamate excitotoxicity. R
  • In weaning piglets, treatment of β-glucan and L-theanine lessened the inflammatory responses against Gram-negative bacterial infection by inhibiting pro-inflammatory cytokines hyperproduction, while enhancing anti-inflammatory cytokine production. R
  • L-Theanine prevented increased expression of NF-κB and down-regulated the pro-inflammatory (interleukin (IL)-1β and IL-6) and profibrotic (TGF-β and CTGF) cytokines. R
  • Under emotional arousal, caffeine and theanine exert opposite effects on certain attentional processes, but when consumed together, they counteract the effects of each other. R
  • Long-term green tea supplementation does not change the human gut microbiota. R
  • Top 6 Proven Health Benefits of Theanine R
  • L-theanine at a particular dose range increases sensorimotor gating in humans R