July, 13 HEALTH

Is L-Theanine Good for Anxiety?

Anxiety is an extremely common mental health illness in the United States and the rest of the world, and it is becoming increasingly prevalent. In fact, between 1990 and 2013, the number of people suffering with anxiety and/or depression rose by 50%. Almost 10% of the world’s population is affected by anxiety or depression, and mental illnesses including these account for a third of the global non-fatal disease burden, especially economically. It has been estimated that 1 in 5 people people in the world are affected by depression and/or anxiety.

Anxiety and depression are often treated in a similar way — with antidepressants — but as these drugs can often have serious side effects, more and more people are starting to look into natural anxiety and depression treatments. But what are some of these safe, natural ways to treat anxiety?

Green tea has been used as a restorative medicine in traditional Chinese medicine for a very long time, and now L-theanine has been extracted from green tea to treat anxiety and depression in China, Japan, and other countries in Asia. They have found that the calming effects of L-theanine compensate for the stimulating effects of caffeine found in teas like green tea and black tea.

Experts believe that diet could play a large role in anxiety treatment, and that foods high in specific compounds could hold the key to improved mental health. One of these compounds is theanine, or L-theanine. Professionals typically agree that theanine could potentially be a strong anxiety treatment.

What is Theanine?

Theanine is an amino acid that is not commonly found in the human diet, as it is not one of the essential or nonessential amino acids. L-theanine is often called a “nondietary amino acid.” Because of its structure, theanine is known to reach the brain quickly following oral consumption. L-theanine is present in various food sources but is found mainly in both green and black teas.

Theanine is found to be relaxing, but not sedating agent, and has been found to help process stress and to improve attention. It has also been found to aid in sleep quality.

When combined with caffeine–like green or black tea–theanine is found to effectively cause improved cognition and attention.

Countries that typically have a high green tea intake, like China and Japan, have a much lower rate of depression than western countries, where green tea intake is not as high. This may provide evidence of a link between L-theanine and the treatment of anxiety.

L-Theanine: A Natural Supplement for Anxiety?

Studies show that increasing intake of theanine can significantly reduce symptoms of anxiety, such as a racing heartbeat and increased secretion of immunoglobulin A in saliva. Its effects are somewhat similar to those of a sedative, but L-theanine is far from this prescription drug. It is actually considered to be an effective anxiolytic, which helps to prevent the brain from producing an anxious response to stressful situations.

Theanine has also been found to aid in sleep, which is a huge proponent of anxiety. Young boys with ADHD were studied to find if theanine would help their sleep. The scientists saw a significant increase in sleep percentage and sleep efficiency scores, and saw less activity during sleep in the boys who took the theanine. The boys took 400 mg daily of L-theanine, and the supplement showed no negative side effects. ADHD and anxiety coexist in many young people in the United States, so this study further proves that L-theanine can be a large help in the management of anxiety, particularly with sleep disturbances.

How Does L-Theanine for Anxiety Work?

L-theanine is processed in the brain through the blood-brain barrier. The blood-brain barrier is similar to a gateway that prevents blood borne substances from crossing over into the brain; it is a form of protection for one of the body’s most important organs. While this barrier is beneficial, it does have its downsides; most notably, it prevents many medications from reaching their target area. Research shows that 98% of small molecule neurotherapies, and 100 percent of large molecule neurotherapies can’t pass through the blood-brain barrier, rendering many types of common treatments for anxiety almost useless.  

L-theanine is different. It uses the leucine-preferring transport system to hitch a ride across the blood-brain barrier, allowing it to target the brain directly. Essentially, theanine is better able to get to where it needs to be efficiently.

Once past the blood-brain barrier, L-theanine enacts a variety of neurophysiological and pharmacological effects. It has been found to up-regulate inhibitory neurotransmitters, and blocks the binding of L-glutamic acid to glutamate receptors in the brain. It has also been found to potentially modulate serotonin and dopamine in select areas of the brain. L-theanine’s inhibition of cortical neuron excitation can have anti-stress effects.

The effects of L-theanine can be tracked via an EEG, but changes in brain electrical activity are dose-dependent. L-theanine has shown similar effects to electrical activity as those of meditation, which includes an increase in alpha waves in the parietal and occipital regions of the brain.

There is still much research to be done on the processes of L-theanine absorption in the body, but it is clear that the way it interacts with neurotransmitters has an effect on stress management, which plays into anxiety regulation.

L-Theanine Dosage for Anxiety

How Theanine Benefits the Brain

Once theanine has crossed the blood-brain barrier, what does it do? This question is tricky to answer with absolute certainty due to the various studies suggesting it does various actions, but it is understood that theanine helps to regulate serotonin levels and dopamine levels in the body, which are chemicals that are ultimately responsible for mood. It is also thought that it can increase levels of a protein called brain-derived-neurotrophic-factor, keeping the brain healthy. When the brain is better able to manage stress, it improves in all of its other functions: memory, cognition, attention, etc.

Sources of Theanine

Theanine is found in various foods, including green and black teas, white tea, C. japonica and C. sasanqua, and a mushroom called Xerocomus badius.

Unfortunately, there are very few opportunities for theanine consumption in the everyday western diet. In Japan, theanine is added to many foods, such as desserts, soft drinks, and herbal teas, but in the United States black teas and green teas are generally the only easily accessible sources.

It is often advised that people take an L-theanine supplement, which can be in the form of L-theanine tablets, L-theanine capsules, or L-theanine powder.

There is currently no official theanine dosage guideline in the United States, although studies have found that doses of up to 400mg per day are typically safe and well tolerated. However, you don’t need to take this much to benefit from theanine. In fact, one study found that just 50mg per day was a good L-theanine dosage for anxiety, which works out to just over 2 cups of tea per day, based on a standard 20mg dose per cup.

After taking L-theanine, participants regularly note a calming effect within 30 to 40 minutes of consumption, with dosages of 50 to 200 mg. These effects often last 8 to 10 hours.

Adding theanine to your diet can be as easy as increasing your tea intake–yummy and stress-relieving!

Is Theanine Safe?

Theanine is one of the safest natural anxiety remedies, and it is unlikely to have any major side effects.

There are few known interactions with theanine, but it is always best to check with your doctor before taking a theanine supplement if you are taking any prescription medications. Theanine may have an impact upon the efficacy of these medications, or it could increase the risk of adverse side effects. Using theanine with antihypertensive drugs may potentiate the activity of antihypertensive drugs. Some antihypertensive drugs include:

• Captopril (Capoten)
• Enalapril (Vasotec)
• Losartan (Cozaar)
• Valsartan (Diovan)
• Diltiazem (Cardizem)
• Amlodipine (Norvasc)
• Hydrochlorothiazide (HydroDiuril)
• Furosemide (Lasix)

Using theanine concomitantly with stimulant drugs may decrease the effects of stimulant drugs. Some stimulant drugs include:

• Diethylpropion (Tenuate)
• Epinephrine
• Phentermine (Ionamin)
• Pseudoephedrine (Sudafed)

Theanine may interfere with herbs and supplements which contain caffeine or have hypotensive properties.

Theanine has been found to be safe when used orally and appropriately, for up to 3 weeks. It is possibly safe for children to take theanine orally under the supervision of a physician. There is insufficient information on the safety of theanine for pregnant and breastfeeding women, therefore it is best to avoid. Orally, theanine is generally well-tolerated although rare side effects may include headaches and facial tics.

Unlike benzodiazepines, L-theanine does not increase drowsiness, slow reflexes, and impair concentration. L-theanine is non habit-forming, as it does not lead to tolerance and dependence when used over long periods of time, unlike prescription benzodiazepine medications, therefore it may be a better option for longer term anxiety treatment.

Theanine, or L-theanine, has proven to be beneficial for many people suffering from generalized anxiety disorders and/or day-to-day anxiety, and is a generally well-tolerated supplement. Some things to keep in mind if you are considering using theanine for anxiety are how accessible it is to you,  if you would like to take it as a tea (with caffeine) or as a supplement, and if its effects would have a positive impact on your life.

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