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L-Theanine is an amino acid commonly found in tea. Theanine, together with caffeine, produce a distinct cognitive enhancement profile without the jitters or other side effects. In addition, theanine has many other surprising health benefits.
There’s something calming about sipping a cup of green tea, and it may be the L-theanine. An amino acid found naturally in green tea and some mushrooms, L-theanine is said to alleviate anxiety, improve sleep, and reduce stress.
To date, scientists have yet to extensively explore the benefits of L-theanine. However, preliminary research suggests it may help lift mood and calm the body’s response to stress and anxiety.
L-theanine (also called theanine, or sometimes r-glutamylethylamide) is an amino acid that impacts nerve impulses in the brain and the release of neurotransmitters, including GABA. It is known as natural ananxiolytic because it can have a calming, sedative effect on the body and mind without making you feel drowsy — which is why it’s often used to reduce anxiety, hyperactivity and sleep-related problems. (1)
L-Theanine, along with other components of green tea, reduced triglyceride and fatty acid levels in the blood. The food intake and body weight decreased in the mice given theanine .
As part of a calorie-controlled diet, replacing a snack with green tea or another low-calorie hot beverage could aid weight loss.
The L-theanine in green tea can create a savory taste, also known as umami flavor. ResearchTrusted Source suggests that umami flavors may reduce appetite, which often helps with weight loss.
L-theanine may help promote weight loss in both a direct and indirect manner. Indirectly, theanine’s ability to calm the nervous system may help weight loss by preventing anxiety and stress, thereby reducing the likelihood of emotional overeating. In “The Ounces Countdown Weight Loss Approach,” author Patrick Hafner reports that theanine increases the release of dopamine, the neurotransmitter responsible for feelings of pleasure and reward, which may also help weight loss by decreasing overeating. Directly, the combination of theanine and catechins, a type of antioxidant found in green tea, may increase thermogenesis and decrease triglyceride levels, which may promote fat oxidation, although this result has only been confirmed in animal studies.
A review article published in the August 2011 issue of the “Journal of the Science of Food and Agriculture” reports that theanine has been linked to improved weight loss and increased feelings of relaxation. Another review article, published in 2006 in the “Journal of Herbal Psychopharmacology,” reports that theanine has been shown to have a relaxing and calming effect on the nervous system and may increase concentrations of mood-enhancing neurotransmitters such as serotonin and dopamine.
L-theanine affects the brain in a number of ways. Acting as a anxiolytic, it is known to amplify alpha brain waves, allowing for a type of calm alertness and even heightened creativity.
Theanine has also been shown to boost levels of GABA, as well as other hormones and compounds that promote calm, focus, regulated mood, and more.
By itself, l-theanine is effective nootropic. But when combined with caffeine…there’s a pronounced synergistic effect. This means you experience heightened focus, awareness, and energy, as well as reduced stress and improved mental endurance to even higher levels.
A hot cup of tea can help anyone feel more at ease, but research suggests it may be the most beneficial for those dealing with high levels of anxiety.
Five randomized-controlled trials with a total of 104 participants found L-theanine reduced stress and anxiety in people who were experiencing stressful situations.
Another study found that it increased relaxation without causing drowsiness and reduced resting heart rate.
A study published in the Journal of Clinical Psychiatry focused on people with schizophrenia or schizoaffective disorder. Researchers found that L-theanine decreased anxiety and improved symptoms.
Green tea is the top source of L-theanine, and many studies have found evidence that green tea can help reduce inflammation and support heart health. Some experts believe that green tea is protective of cardiovascular health mostly because it provides theanine, rather than due to other active compounds like green tea catechins or theaflavins.
Theanine may help to prevent blood pressure spikes in response to stressful events and help regulate nitric oxide. Nitric oxide is a molecule that our bodies produce to help cells communicate, regulate blood pressure by dilating arteries, reduce inflammation, support the immune system, improve sleep quality and more. The endothelium layer of our arteries produce nitric oxide, which helps relax narrowed blood vessels and increases oxygen and blood flow. Adequate production of nitric oxide can help to protect against artery-blocking clots or obstructions, heart attacks, stroke and other cardiovascular problems.
Some studies have also found that administration of L-theanine after a stroke, ideally within 12 hours but potentially up to 24 hours later, may help protect brain cells and reduce damage caused by the stroke. (10)
To date, little is known about the safety of using L-theanine supplements in the long term. L-theanine is generally considered safe when consumed in green tea. However, the National Institutes of Health (NIH) cautions against drinking more than five cups of green tea daily.
There’s also some concern that taking L-theanine in combination with sedatives, lipid-lowering medications, and/or drugs used in chemotherapy may produce harmful effects.
Dietary supplements have not been tested for safety. Because they are largely unregulated, the content of some products may differ from what is specified on the product label.
- Research studies generally use from 200 – 400 mg of L-theanine
- Typical supplements come in 50 – 100 mg capsules, taken 1 – 4 times daily