This article is shared with permission from our friends at Vitagene.

Anxiety is a very common mental health disease in the United States, it’s becoming increasingly prevalent. In fact, between 1990 and 2013, the number of people suffering with anxiety and/or depression rose by 50%. Anxiety and depression are often treated in a similar way — with antidepressants — but as these drugs can sometimes have side effects, more and more people are starting to look into natural anxiety treatments. But what are some safe, natural ways to treat anxiety?

Experts believe that diet could play a big role, and that foods high in some specific compounds could hold the key to improved mental health. One of these compounds is theanine, or L-theanine, with professionals typically agreeing that there could potentially be a strong theanine-anxiety association.


What is Theanine?

Theanine is an amino acid that’s present in both green and black teas. 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 anxiety, highlighting a possible treatment.

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 secretory immunoglobulin A in saliva, for example. Its effects are somewhat similar to those of a sedative, but L-theanine is not a sedative. It’s actually considered to be an effective anxiolytic, which helps to prevent the brain from producing anxious responses to situations.

How Does L-Theanine for Anxiety Work?

It all comes down to the blood-brain barrier. The blood-brain barrier (BBR) is like a gateway that prevents bloodborne substances from crossing over into the brain; it’s 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 that it prevents many medications from reaching their target area. Research shows that 98 percent 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 pretty much useless.


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

How Theanine Benefits the Brain

Once theanine has crossed the blood-brain barrier, what does it do? This part is trickier to say with absolute certainty, 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’s also thought that it can increase levels of a protein called brain-derived-neurotrophic-factor, keeping the brain healthy.

Sources of Theanine

Unfortunately, there are very few sources of theanine 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 really the only easily accessible sources. That’s why it’s often advised that people take an L-theanine supplement, which could be 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 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 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.

Is Theanine Safe?

Theanine is one of the safest natural anxiety remedies, and it is unlikely to have any side effects. There are few — if any — known interactions, although it is always best to check with your doctor before taking a theanine supplement if you are taking any prescription medications. This is because theanine may have an impact upon the efficacy of these medications, or it could increase the risk of adverse side effects.

Want to know whether theanine is right for you? Vitagene provides actionable intelligence about your ancestry, health traits, and helps you create healthy, lasting change in your life with a diet, exercise, and supplement recommendations based on your DNA, lifestyle, family history, and goals. 

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