Everything you should know about L-theanine

L-theanine is an amino acid most commonly found in black and green tea leaves. It can also be found in small amounts in some mushrooms. According to many studies, L-theanine relieves anxiety or stress and is also used for insomnia problems. Thanks to these relaxing effects, it is part of many dietary supplements. Before purchasing a product containing L-theanine, read this article to learn about the potential benefits and risks associated with this amino acid.

Benefits of L-theanine

Although L-theanine is best known for its relaxing effects, there are many more potential health benefits associated with this amino acid. Which ones are they?

Relief from anxiety and stress

Have you noticed that sipping a cup of warm tea has a relaxing effect on you and you just feel a lot better afterwards? It's not just your feeling. Some scientific researches have come to the conclusion that consumption of L-theanine has a relaxing effect on people, without causing drowsiness and lowering the heart rate. [ 1 ] A controlled study with 104 participants links L-theanine to reduced levels of stress and anxiety in people experiencing stressful situations. [ 2 ] Another study published in the Journal of Clinical Psychiatry examined patients with schizophrenic disorders, and in this case, the results speak of a reduction in anxiety and an alleviation of the symptoms of said disorders. [ 3 and 4 ]

Support for concentration

Especially in combination with caffeine, L-theanine can increase concentration and attention. According to one study, after consuming 97 mg of L-theanine and 40 mg of caffeine (a classic cup of coffee contains about 95 mg of caffeine), participants were able to focus significantly better while performing demanding tasks. In addition, study participants felt more energetic and less tired. [ 5 ]

Improving immunity

According to some research, L-theanine improves the functioning of the immune system. A study published in the journal Beverages suggests that L-theanine helps reduce upper respiratory infection rates. [ 6 ] In conjunction with catechins (antioxidants) from green tea, L-theanine is associated with preventive effects against influenza. [ 7 ] Another study concluded that L-theanine has an anti-inflammatory effect in the digestive tract. [ 8 ] To confirm these conclusions, however, it is necessary to carry out further research that will confirm their validity.

In the fight against cancer

L-theanine is associated with enhancing the effects of some chemotherapy drugs used in the treatment of tumors. [ 9 ] This is a potential possibility to increase the effectiveness of chemotherapy in the fight against cancer. Official data that there is a correlation between drinking tea and a lower incidence of cancer does not yet exist. However, some studies suggest that people who drink tea regularly have a lower incidence of cancer. [ 10 ] An experiment was conducted in China with women diagnosed with ovarian cancer, and according to its results, patients who drank at least one cup of green tea a day lived longer. [ 11 ] Another study found that women who regularly drank green tea were 32% less likely to develop pancreatic cancer. [ 12 ]

Blood pressure under control

Another group for whom L-theanine can be beneficial are people with increased blood pressure in stressful situations. According to the results of one study, L-theanine helped lower blood pressure in people who usually experienced an increase in it during specific mental tasks. [ 13 ] Caffeine also achieved similar, albeit slightly less favorable, effects.

For better sleep

Other research suggests that L-theanine benefits quality sleep, which is probably related to its relaxation effects described above. In the conclusions of one study, scientists write that in doses of 250 mg and 400 mg L-theanine significantly improves sleep in both humans and animals. [ 14 ] Furthermore, L-theanine at 200 mg has been shown to help reduce heart rate and thus promote relaxation of the body. [ 15 ]

It also helps boys with diagnosed attention deficit hyperactivity disorder (ADHD) to sleep better. The study examined the effects of L-theanine on 98 boys between the ages of 8 and 12. The randomized group was given two tablets with 100 mg of L-theanine twice a day. The other group received placebo pills. After 6 weeks, the L-theanine group had significantly longer and more restful sleep. [ 16 ] Although these results sound promising, more research will be needed to confirm the efficacy and safety of L-theanine administered to children.

L-theanine: risks and side effects

Since no side effects of consuming L-theanine have been confirmed so far, the use of teas and supplements containing L-theanine is considered safe.

Here, however, it is necessary to state that some research indicates that teas containing amino acids may contain components with potentially negative effects for oncology patients. Data from the Memorial Sloan Kettering Cancer Center, an American cancer treatment center, links the polyphenol EGCG, commonly found in green tea, to a reduction in the effectiveness of some chemotherapy drugs. [ 17 ]

Oncology patients who are undergoing chemotherapy treatment should therefore always consult their attending physician in advance about the use of green tea and supplements with L-theanine.

It should also be mentioned that due to the caffeine content, consuming large amounts of green tea can lead to stomach upset or irritability. Pregnant and lactating women should definitely limit caffeine intake.

Recommended dose of L-theanine

The recommended dosage of L-theanine does not yet have sufficient support in research and scientific data, and thus has not yet been established. However, you will certainly not make a mistake if you follow the general recommendations for caffeine consumption in this direction. If in doubt, do not hesitate to consult your doctor.

L-theanine in Mindflow products

We are very well aware of the benefits L-theanine brings, which is why we used its positive effects when formulating the composition of several products. You can find this amino acid in the following products: Focus 2.0 , Focus Decaf , Active Coffee , Focus Chocolate and Sleep .