An ingredient in green tea, theanine, could both strengthen the immune system and have a relaxing effect.

It was during the World Tea Expo EAST1, held in Boston, the German biochemist Reinhold Zenger introduced this compound that gives rise to increasing interest of scientists. Reinhold Zenger is responsible for the division devoted to tea, the company Plantextrakt.

Theanine is an amino acid present in the root of tea plant. The tea leaves contain from 1% to 2% on average.

It says that science

The scientific data are still preliminary, but they still arouse the interest of researchers. For example, during a trial in Florida, 124 subjects were taken during 3 months, capsules containing theanine and epigallocatechin gallate (EGCG).

According to the results, people have contracted treated fewer colds and flu than those taking a placebo, and their symptoms were less intense and long when they were malades2. The researchers collected blood samples and found in vitro that the blood of subjects produced more molecules stimulating an immune response. “If you want to strengthen your immune system, drink green tea! “Exclaimed Reinhold Zenger.

Theanine also has a relaxing effect. According to data presented by Reinhold Zenger, this substance stimulates production of alpha waves in the cerveau3. “Things have been subjected to intense physical exercise. Those who took the theanine to calm returned much more quickly than those who had been given a placebo, “he said based on a study published in 20014.

“People who have trouble relaxing, and there are many in our society, should take green tea, has advised smile, the biochemist. It keeps performance while being less stressed, because it contains both caffeine and theanine.

The cup of tea

More tea leaves are, the more they contain theanine. “The green teas from the region of Yunnan, China, are those which contain the most,” said Reinhold Zenger. Prolonged exposure to sunlight reduces the amount of theanine, which gives an advantage to teas that are grown under shade. “During my last visit to China, I noticed that several farmers had adopted this mode of culture,” he said.

More tea is infused, the more it contains theanine, also said the biochemist. The active dose of theanine is 200 mg, the level of 3 to 5 cups of green tea.

However, during a preliminary trial published in 2008, we obtained an effect with a dose of 50 mg as a supplement. According to the authors, theanine has had a calming effect, but without causing somnolence5. Theanine capsules are available commercially: the dosage generally varies between 100 mg and 200 mg.

Many teas and products of tea boast their antioxidant content, but few are now posting their content theanine.