The link between L-Theanine and sleep

Sleep deprivation is associated with a higher risk of various chronic diseases such as depression, obesity, cardiovascular disease, diabetes, and leads to reduced quality of life as well as negative socioeconomic consequences . Substances that induce sleep, such as medications and herbs, can often lead to dependence and other side effects. Meanwhile, L-theanine (γ-glutamylethylamide), a naturally occurring amino acid found abundantly in tea leaves, has anxiolytic effects through the generation of α brain waves without addiction and other side effects. associated with normal sleep induction.

L-Theanine is an amino acid found mainly in green and black tea or some mushrooms. It is also available in pill form. It is known that L-Theanine can help relieve anxiety, stress and reduce insomnia.
Most people know that L-theanine helps people relax, however, this compound has many other potential health benefits such as:
Reduce anxiety and stress
Sip a cup of tea Heat can help you feel good, and research also shows that it not only relaxes the mind, but doesn't cause drowsiness. A review of 5 randomized controlled trials involving 104 participants, 4 trials using L-Theanine showed reduced stress and anxiety in those exposed to stressful situations. Another study published in the Journal of Clinical Psychiatry focused on people with schizophrenia or a schizophrenic disorder. Researchers found that L-Theanine reduced anxiety and improved symptoms.
Increases concentration
Combined with caffeine, L-Theanine can help increase focus and attention. One small study found that a combination of L-Theanine 97mg and caffeine 40mg helped a group of young adults focus better on assigned tasks. A typical cup of coffee contains 95mg of caffeine. Most study participants also felt more alert and less tired.
Strengthens the immune system
Some authors suggest that L-Theanine can improve the function of the body's immune system. A study published in the journal Beverages found that L-Theanine may help reduce upper respiratory tract infections. While another study also showed that the antioxidants in green tea and other antioxidants may be effective in preventing flu. In addition, L-Theanine may also help improve inflammatory symptoms in the intestinal tract. However, more research is needed to confirm and expand on these findings.
Aids in Tumor and Cancer Treatment
L-Theanine has also been implicated in amplifying the anti-tumor effects of some chemotherapy drugs. Because of these promising findings, the researchers hope that L-Theanine may also help improve the anti-cancer effects of chemotherapy. Although there is no clear evidence that tea prevents cancer, some studies show that people who regularly drink tea have lower rates of cancer. A study in China found that women diagnosed with ovarian cancer who drank at least one cup of green tea a day lived longer than those who didn't. Another study in tea drinkers versus non-drinkers found that women who drank green tea were 32% less likely to develop pancreatic cancer.
Controlling blood pressure
L-Theanine may be beneficial for people who develop high blood pressure after experiencing stressful situations. One study found that L-Theanine helped lower blood pressure in these cases. In the same study, researchers noted that caffeine had a similar but less beneficial effect. Some studies indicate that L-Theanine can promote a good night's sleep, this may be because it helps promote relaxation during sleep.
In one trial, scientists showed that doses of 250 mg and 400 mg of L-Theanine significantly improved sleep in animals and humans. Additionally, taking 200 mg of L-Theanine daily has been shown to reduce resting heart rate, pointing to this compound's ability to promote relaxation.
L-Theanine may also help boys diagnosed with attention deficit hyperactivity disorder (ADHD) sleep better. One double-blind study looked at the effects of L-Theanine on 98 boys aged 8 to 12 years. A random group was given two 100 mg L-Theanine tablets twice daily. The other group received a placebo drug. After 6 weeks, the group taking L-Theanine had longer, more restful sleep. Although the results are promising, more research is needed before it can be proven safe and effective, especially for children.
Meanwhile, another study in people diagnosed with schizophrenia also found that L-Theanine improved sleep quality in this subject.

Currently, no confirmed or direct side effects of L-Theanine use have been documented. In general, drinking tea and taking supplements containing L-Theanine products is so far safe. But it's important to note that the U.S. Food and Drug Administration (FDA) doesn't set standards. Manufacturers are solely responsible for ensuring their products are safe.
However, although some studies show promising results for the anti-tumor properties of L-Theanine, some teas that contain amino acids may have other ingredients that may be harmful to those people being treated for cancer. According to Memorial Sloan Kettering Cancer Center, the polyphenol EGCG found in green tea may decrease the effectiveness of certain chemotherapy drugs, such as Bortezomib. For that reason, it's important for people taking chemotherapy drugs to talk to their treating doctors before deciding to drink green tea as part of their treatment plan.
Although no side effects have been reported from taking L-Theanine, because of the caffeine content of tea leaves, consuming large amounts of green tea can lead to symptoms such as nausea, abdominal pain, irritability. harsh, uncomfortable.
Women who are pregnant or breastfeeding also limit the amount of tea they drink to avoid caffeine overdose. To be on the safe side, consult your doctor about what might be of use for you.

Because there are no formal conclusive studies, a safe dose of L-Theanine is not known. But general caffeine dosing guidelines can be helpful if you use tea. It is best for people taking L-Theanine supplements to consult their doctor for dosage instructions.
Meanwhile, a study on safe sleep therapy recommends that supplementing with 200 mg L-Theanine before bed may help improve sleep quality not by sedation but through anxiety-reducing effect. Because L-Theanine does not cause daytime sleepiness, it can be used at any time of the day. No adverse effects have been observed with oral L-Theanine supplementation at doses above 2000 mg/kg/day.
In summary, L-Theanine and sleep are linked, helping to promote relaxation without drowsiness. Unlike common sleep inducers, L-Theanine is not a sedative but a compound that promotes sleep quality through anxiolytic effects. From there, it is shown that using L-Theanine properly, properly and in the right dosage is a safe and effective natural sleep aid.

References: pubmed.ncbi.nlm.nih.go, healthline.com