Article at a Glance
- L-theanine is an amino acid found in green and black tea.
- Studies show that, even with 50mg doses mimicing normal dietary behavior, theanine increases production of alpha brain waves, which are the brain waves that increase creativity and decrease depression.
- Theanine is a glutamate antagonist, meaning it blocks glutamate receptors in the brain, which is part of the reason some people report a calming effect after taking theanine.
- Theanine has also shown promise as a sleep aid and in stopping the release of histamine from mast cells.
- Despite efficacy at 50mg doses, many theanine supplements up this dose to 100mg and beyond, so keeping an eye on dose is important.
- Also, be aware that some supplements that claim to have proven efficacy in studies, such as Alpha Brain, are really just piggy backing on previous theanine research showing theanine effective at increasing alpha brain waves at 50mg doses.
If you’re researching L-theanine, also known as theanine, you may already know that it’s an amino acid, found in green and black tea, that boosts mood, and promotes a sense of calm without drowsiness. I will let Aaron get into the science of how L-theanine works to create these benefits later in this post, but before I do, I want to describe how I felt when I took L-theanine for the first time.
As you’ll see, it made me really nice to the people at Hertz rent-a-car.
- Why I supplement with L-theanine
- L-theanine can help balance glutamate levels
- How L-theanine makes me feel
- L-theanine and alcohol
- Not an everyday supplement for some people
- L-theanine benefits – proven by studies
- L-theanine and allergy
- L-theanine mechanism of action
- L-theanine dosage and complementary supplements
- Choosing a theanine supplement
- Theanine supplement comparison
Why I supplement with L-theanine
Please do not take this as an endorsement of her work on autism, of which I do not have an informed opinion, but I have found the the top level nutrigenomic theories outlined in Dr. Amy Yasko’s book Feel Good Nutrigenomics very useful. It was Dr. Yasko’s discussion of the glutamate/GABA ratio that first motivated me to use L-theanine as stand alone supplement.
Dr. Yasko believes the first step in crafting an effective health regimen is tackling imbalances in the glutamate/GABA ratio. Glutamate and GABA are both essential neurotransmitters, with important roles to play in cognitive function, however, when glutamate levels get too high, as they can during times of prolonged stress, when GAD1 mutations are present, or on a high glutamate diet, the usually beneficial glutamate can become an excitotoxin. (R)
In fact, elevated glutamate has been linked to a number of neurological diseases. (R)
See also: The MSG in your supplements
L-theanine can help balance glutamate levels
One of the supplements Yasko recommends to get glutamate levels under control is, you guessed it, theanine.
Here is what Dr. Yasko has to say on the issue:
Addressing imbalances in the glutamate / GABA ratio as well as the calcium to magnesium ratio is what I consider the starting point of this program.
Look to support with nutrients that help calm the nervous system including GABA, THEANINE, valerian root, pycnogenol, grape seed extract, resveratrol, and CoQ10.
Theanine is an important supplement for glutamate/GABA balance because it blocks glutamate receptors in the brain. (R) One of the primary reasons people experience an anti-anxiety effect when taking theanine is due to this glutamate blocking activity.
How L-theanine makes me feel
In a word, great. L-theanine gives me a calm, creative focus. I feel unrestrained by mental clutter and notice a marked improvement in mood.
For example, I was recently in San Diego, where I visit often, and was returning a Hertz rental car. When I returned the car, the people at Hertz ignored me for a very long time, taking their sweet time processing my car. This would have irritated me under normal circumstances (many years in NYC gives you this ridiculous sense of time when it comes to the performance of services, you want it now!). However, rather than indulge in a moment of self imposed stress, I waited patiently. When the Hertz man finally came over, I asked how his day was going.
I went into duck mode, water rolled off my back.
Overall happier, calmer, and less stressed. I felt a noticeable increase in creative energy. I normally have lots of ideas, but the increased focus allowed me to digest and organize, rather than feeling overwhelmed by all the things I wanted to create/ things I had to do.
As I used theanine over the course of a week, I found that it was also a meditation aide.
L-theanine and alcohol
I have found that theanine can also be a fun supplement to take socially. I will normally take 100mg prior to a night of drinking as it can reduce the effect of a hangover, and adds to the relaxing effects of alcohol. (R) How does theanine reduce hangovers? It appears theanine speeds the metabolism of alcohol by helping the body produce glutathione, although the study we cite to here is in mice and not yet established. However, I can attest anecdotally to theanine being helpful at reducing the impact after a night of drinks.
Not an everyday supplement for some people
Theanine produced solid benefits for me, both in work and socially, and I will definitely continue using it, however, it is contraindicated for those on high blood pressure medication because it lowers blood pressure. (R) When I’ve taken high doses for a number of days in a row, I have noticed a few episodes of light headedness after standing.
I wouldn’t recommend taking high doses of lumbrokinase, nattokinase or N-acetyl-cysteine alongside theanine, especially for lengthy periods of time.
Theanine will be a 1-2 times a week supplement for me, and potentially more frequently when I am looking to balance glutamate/GABA ratios.
L-theanine benefits – proven by studies
Ok, now we dig into some of the more noteworthy studies evaluating theanine.
There have been a number of studies looking at the benefits of L-theanine. The FDA considers theanine as a GRAS (“Generally recognized as safe”) supplement.
In a randomized, double blind study, theanine was shown to significantly improve sleep quality in boys with ADHD. (R)
This study found that L-theanine prevented the cold and flu and had an immune boosting effect “enhancing gamma-delta T cell function.” The New York Times, reporting on the study, had this to say in summary:
Tea increases the body’s defenses against infection and contains a substance (L-theanine) that may be turned into a drug to protect against disease, a study has found. Coffee does not have the same effect, the researchers say in an article today in Proceedings of the National Academy of Sciences. A component in tea primes the immune system to attack invading bacteria, viruses and fungi, the study concluded. An experiment showed that immune system blood cells of tea drinkers responded five times faster to germs than did the blood cells of coffee drinkers.
There are a few studies that show L-theanine improves alpha brain wave function, even at low 50 mg doses meant to mimic “normal dietary levels.” (R)
I am now passing the mic to Aaron for a deeper dive into how L-theanine works in the body.
L-theanine and allergy
Thanks, John. L-theanine’s “mechanism of action” is quite interesting.
L-theanine has shown some promise as a modulator of allergic reactions. (R) A major event in allergic reactions is the secretion of histamine from immune cells known as mast cells. Mast cells can be thought of as the first responders of the immune system, they are constantly sensing the environment and when they detect something potentially harmful they secrete a wide range of factors to kick start the immune response. When mast cells detect something as harmful (even if it’s harmless) this causes an allergic reaction. (R) Theanine inhibits histamine release from mast cells.
Interestingly, this inhibition of histamine also ties in with L-theanine’s glutamate inhibitory activities as well. Histamine can induce glutamate release (R), which as we’ve established above, is an excitatory neurotransmitter our bodies need. Excess histamine may cause an unhealthy build-up of glutamate, although there is some evidence that there is an upper maximum of glutamate build-up associated with histamine (R).
L-theanine mechanism of action
So the interesting questions then becomes how does L-theanine link all these together, and is there a single gene or SNP which is of particular interest?
Lets look at histamine first, a major gene involved in histamine metabolism is AOC1, which encodes for the enzyme Di-amine Oxidase (DAO – pay attention to that abbreviation as it’s the cause of much confusion). In health DAO functions to break down histamine following its release from mast cells, curtailing the immune response. There are several SNPs within AOC1 which are associated with reduced DAO activity, resulting in histamine intolerance, which is characterized by symptoms often associated with allergy such as headaches, flushing of the skin and irritation (R).
The benefit of L-theanine here is clear. By suppressing histamine release from mast cells (R), it is prevented from building up to harmful levels, even in those with reduced DAO activity.
We’ve already described how L-theanine can inhibit stress by blocking glutamate receptors (R). As excess histamine can lead to the buildup of glutamate there’s a clear mechanism for impaired DAO activity leading to increased histamine, leading to increased glutamate. L-theanine works by both preventing histamine release, and also blocking glutamate activity as well.
AOC1/DAO and DAO/DAAO
There’s a nice indirect mechanism linking DAO, histamine and glutamate.
However, if you read around on the internet, you may find articles discussing a direct action for DAO interacting with glutamate. While there may be evidence linking them directly I’ve not come across it; rather I think it’s a case of confusing DAO the enzyme with DAO the gene. DAO is encoded for by the AOC1 gene and functions to breakdown histamine (R). There is however a DAO gene which confusingly encodes for an enzyme called d-amino acid oxidase (DAAO), which is involved in glutamate metabolism (R).
See also: You say DAO, I say DAAO
Quite why it seemed a good idea for DAO to be encoded for by AOC1 and DAAO to be encoded for by DAO I’ll never know, but I think this is the basis for much confusion. So be careful when you’re trying to interpret your genetic results!
L-theanine dosage and complementary supplements
Ok, taking the mic back from Aaron for some closing thoughts.
I have found L-theanine to be an effective nootropic that produces a calm focus. For me, it’s an effective tool for writing, meditating, creative bursts, and even to unwind and get to sleep at the end of the day. I also like it socially.
If you’re using theanine as an anti-anxiety supplement, the calming effects for me were greatest when paired with GABA and valerian. Keep in mind that both GABA and valerian can upset the stomach, so start slow. I also don’t recommend this stack for daily use over extended periods of time, best to cycle on and off.
As we discussed, theanine lowers blood pressure. Because there can be side effects, I would encourage everyone to experiment with different doses to see what amount of theanine suits them best. Some will tolerate 200mg quite well, while others may want to dose more in line with the studies that used 50mg.
Choosing a theanine supplement
If you’ve read thus far and want to add theanine to your supplement stack, I’ve included a short section below that gives a tour around some of the best theanine products on the market, standalone supplements, as well as a couple blends that have positive reviews and are made with good manufacturing practices from brands I trust.
Theanine supplement comparison
|Jarrow Formulas Theanine 100||100mg L-theanine||60/ct|
|Onnit Alpha Brain||650mg Onnit Flow Blend (L-tyrosine, L-theanine, oat extract, phosphatidylserine), 350mg Cat's Claw bark extract, 240mg Onnit Focus Blend (L-alpha GPC, Bacopa extract, Huperzia serrata extract), 65mg Onnit Fuel Blend (L-leucine, vinpocetine, pterostilbene), 10mg Vitamin B6||90/ct|
|Jarrow Formulas GABA Soothe||225mg Ashwagandha extract, 100mg GABA, 100mg Suntheanine||30/ct|
This is the theanine I take, although I take the 100mg capsules. Jarrow also makes a 200mg capsule if you find you do well with larger doses of theanine. In both cases, the capsules are easily broken apart so you can experiment with smaller doses. Remember, it’s the 50mg dose that triggered the increase in alpha brain waves in the studies, and the 50mg dose is also closer to what you’ll find in tea, but in today’s culture we assume that more is always better, which isn’t necessarily true. I will often take apart a 100mg capsule and empty out approximately 40-50mg so I have a conservative dose. Another advantage of the Jarrow products is they use a high quality theanine, called Suntheanine.
Note: I don’t take Alpha Brain.
As a resident of Austin, Texas, I am perhaps more familiar than most with Onnit, the supplement brand started by Aubrey Marcus. You also may have heard of Onnit if you listen to the Joe Rogan podcast, as Joe has a stake in the company. Alpha Brain is one of Onnit’s top selling nootropic supplements, and it features a 200mg dose of theanine, along with a host of other ingredients, including tyrosine.
Reviews, both on the Onnit website, as well as on Amazon, are mixed, with some swearing by the product and others finding no benefit. Since Onnit adds tyrosine to the formula, efficacy may have something to do with the user’s dopamine receptor genes. We wrote a blog post on how genetics impact tyrosine metabolism, which I’d encourage you to read if tyrosine becomes a part of your supplement regimen.
I would also note that amino acids like tyrosine compete for uptake in the brain with tryptophan, which is the precursor to serotonin, so watch closely how this product makes you feel. For more on the impact of food and supplements on serotonin, see how to boost serotonin naturally and safely. As with standalone theanine blends, it’s best to cycle on and off of Alpha Brain, and be conservative with dosage.
I mention Alpha Brain in this post because I know they use quality ingredients, and because Onnit did a clinical trial that showed Alpha Brain improved alpha brain state, verbal recall and focus. Of course, this isn’t a big surprise because, as we know from theanine studies, theanine alone would likely have yielded all of these results, but nonetheless, conducting the trial is a sign of good faith and professionalism.
Note: I don’t take GABA Soothe.
But it is an interesting product because it blends theanine, GABA and ashwagandha, and adaptogenic herb used to promote relaxation. Now, you’ll remember, that for stress relief, I found theanine most effective when paired with GABA and valerian. This product adds GABA to the formula, as well as an herb that is popular with many people for reducing anxiety. The issue I see here is that the dose of GABA is very small.
There is a lot of controversy over whether GABA can cross the blood brain barrier as we know theanine does. Many say it cannot, however, in light of the fact that GABA moves out of cells much faster than it moves in, it may just be difficult to measure. For those who don’t need a large dose of GABA, this could be a product worth trying. However, as a point of reference, when I take GABA, I take a 750mg dose, which is 7 times higher than the GABA content of GABA Soothe.