7 Surprising Wellness Benefits of L-Theanine

If you’ve ever enjoyed a warm cup of green or black tea, you’ve also sipped some l-theanine. This amino acid is found in tea leaves and certain types of mushrooms, according to The Sleep Doctor. It creates delicious umami, the savory, brothy flavor found in Japanese cuisine. But, it turns out that this compound does more than just season your food. Keep reading to find out all the wonderful health benefits of l-theanine.

Could improve mental focus
If you’re looking to improve mental focus, l-theanine could help stay alert and improve cognitive function. According to a 2008 study published in Asia Pacific Journal of Clinical Nutrition, researchers observed l-theanine increasing alpha activity in the brain, which plays an important role in attention span and alertness. In fact, l-theanine is considered a nootropic, or “smart drug” because it may boost brain health, according to Medical News Today.

Helps promote restful sleep
Have trouble falling asleep at night? Try adding some l-theanine to your supplement regime. According to the Aspen Brain Institute, neuroscientist Dr. Huberman recommends taking 100-400 mg of l-theanine about an hour before bed to promote a good night’s rest. That’s because l-theanine boosts calming brain chemicals, like GABA, to help ease into sleep.

May boost immunity
Your immune system helps your body fight off disease, and l-theanine may help that immune response. In a 2016 study published in Beverages, researchers observed the potential health benefits of l-theanine to improve immune function and to help prevent diseases like cancer. So sip some green or black tea, a source of this healthy amino acid.

Could help reduce blood pressure
High blood pressure means your body has to work harder to pump blood, which can lead to cardiovascular disease, according to the Mayo Clinic. If you have high blood pressure, consider consuming l-theanine (of course, make sure to ask your doc first). As RxList points out, the amino acid has been found to lower blood pressure. It may also reduce stress and anxiety, which can agitate your cardiovascular system. 

Promotes relaxation
If you need a chill pill, keep some l-theanine around. According to Psychology Today, l-theanine is referred to as an anxiolytic, a type of compound that promotes relaxation and may reduce anxiety. A 2020 study published in Plant Foods for Human Nutrition supports that theory, observing that the consumption of l-theanine found in green tea helps lower anxiety levels and manage stress. 

Aids in preventing colds and flu
Nutritionists in Japan had a hunch one day: They noticed that a group of school children had fewer cases than normal of the flu. Unlike your average group of kids, these children lived near a tea plantation and drank a lot of green tea! In a 2011 paper published in The Journal of Nutrition, researchers credited the consumption of tea catechins and l-theanine for the lower cases of the flu. These compounds could enhance immunity and prevent the occurrence of flu symptoms.

May reduce inflammation
Inflammation happens when your body activates your immune system and sends out inflammatory cells,According to Cleveland Clinic . And, l-theanine may reduce inflammation that can cause swelling and inflamed cells after illness or injury. A study published in the Journal of Parenteral and Enteral Nutrition, l-theanine was found to have immunomodulatory effects, such as reducing inflammation in the intestines particularly after surgery.