L-Theanine

L-theanine is an amino acid found primarily in green and black tea and some mushrooms. It is also available in pill or tablet supplement form.

It is said to help relieve anxiety, stress and reduce insomnia.

Before you try it yourself, find out more about the potential health benefits as well as any risks or complications.

Benefits and Uses of L-theanine

Best known for helping people relax, L-theanine would have other potential health benefits, including:

Anxiety and stress relief

Sipping a cup of hot tea can help you feel at ease, and research suggests that it not only relaxes the mind, but also does so without causing drowsiness.

In a review of five randomized controlled trials that included 104 participants, four studies linked L-theanine with a reduction in stress and anxiety in people experiencing stressful situations.

Another study published in the Journal of Clinical Psychiatry focused on people living with schizophrenia or schizoaffective disorder. Researchers found that L-theanine reduced anxiety and improved symptoms.

Increased concentration

Combined with caffeine, L-theanine can help increase concentration and alertness.

One small study found that a combination of L-theanine (97 milligrams or mg) and caffeine (40 mg) helped a group of young adults focus better during challenging tasks. A typical cup of coffee contains 95 mg of caffeine.

The study participants also felt more alert and less tired in general.

Improved immunity

Some research suggests that L-theanine may improve the function of the body's immune system. One study published in the journal Beverages found that L-theanine could help reduce upper respiratory tract infections.

Another found that green tea catechins - antioxidants - and theanine could be effective in preventing the flu.

Another study found that L-theanine could help improve inflammation in the intestinal tract. However, more research is needed to confirm and expand these findings.

Cancer and cancer treatment

L-theanine has also been associated with amplifying the anti-tumor effects of certain chemotherapy drugs. Because of these promising results, researchers expect that L-theanine may also help improve the ability of chemotherapy to fight cancer.

Although there is no conclusive evidence to show that tea prevents cancer, a number of studies suggest that people who regularly drink tea have lower rates of cancer.

Researchers in one 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 did not.

Another study that looked at tea drinkers compared to non-drinkers found that women who drank green tea were 32% less likely to develop pancreatic cancer.

Blood Pressure Management

L-theanine may be helpful for those who suffer from increased blood pressure in stressful situations.

One study found that people who usually had higher blood pressure after specific mental tasks found that L-theanine helped reduce the increase in blood pressure.

In the same study, researchers noted that caffeine had a similar but less beneficial effect.

Some research indicates that L-theanine may be helpful in getting a good night's sleep, which may be because it helps promote relaxation.

Researchers in one study found that 250 mg and 400 mg doses of L-theanine significantly improved sleep in animals and humans.

In addition, 200 mg of L-theanine has been shown to help reduce resting heart rate, indicating its ability to promote relaxation.

L-theanine may also help kids diagnosed with attention deficit hyperactivity disorder (ADHD) sleep better.

A double-blind study examined the effects of L-theanine on 98 boys between the ages of 8 and 12. One randomized group was given two 100 mg chewable tablets of L-theanine twice a day. The other group received placebo pills.

After 6 weeks, the group taking L-theanine had longer and more restful sleep. Although the results are promising, more research is needed before it can be proven safe and effective, especially for children .Other research suggests that L-theanine has improved sleep quality for those diagnosed with schizophrenia .