Theanine is an amino acid unique to tea and one of the important flavor substances of tea.

The neuroprotective effects of theanine, especially in "mental health" such as improving cognitive levels, alleviating anxiety, improving sleep quality, and improving depressive symptoms, have gradually been confirmed. Therefore, theanine is called "happiness amino acid" by some scholars.

The neuroprotective effect
of theanine in animal experiments showed that theanine could trigger antidepressant and antioxidant activity effects in depressed mice.

Through double-blind, randomized controlled studies, it was found that L-theanine could effectively affect the cognitive function of participants aged 50 ~ 69; A randomized controlled trial in 30 healthy individuals found that taking L-theanine (200 mg/day) for 4 weeks was able to improve sleep quality through anxiolytic effects.

Compared with the intake of theanine alone, the synergistic effect of theanine complex formula, especially theanine and caffeine, is more significant in promoting "mental health".

In a combination of theanine (27 mg) and caffeine (100 mg) in 50 subjects, a significant increase in cognition was found.

丨The effect of theanine on α waves in the human brain

The anti-aging effect
of theanine In the anti-aging model bio Caenora elegans, theanine intervention from the adult stage can extend the average and maximum life expectancy by about 3.6% and 3.2%, respectively.

Under heat stress and oxidative stress, theanine (100 mg/mL) significantly increased the average lifespan of nematodes by 2.12% and 8.21%, respectively. Theanine can reduce the level of oxidative damage in the cerebral cortex of male mice in spatial isolation and improve their survival rate.

In the forced activity space environment, theanine (6 mg/kg) can effectively improve the degree of brain atrophy in fast-aging mice and maintain the brain volume of normal aging mice.

Therefore, theanine also has a positive effect on delaying aging and preventing senile diseases.

Immunomodulatory effect of theanine

According to the Proceedings of the National Academy of Sciences, theanine has the ability to improve the body's immune function and anti-infection ability.

Huo Dongxiao et al. found that L-theanine inhibits cytokines to regulate immune cells and relieve inflammatory response. Appropriate dose of L-theanine (200 mg/kg) can regulate immune effects by improving intestinal development and health, and have a beneficial effect on the growth performance of broiler chickens.

Taking theanine compound preparation can enhance human (23.3 mg/kg, oral) and mouse (120 ~ 700 mg/kg, gavage) cellular immunity and humoral immune function.

In the intervention experiment of SD male rats, it was found that L-theanine (600 mg/(kg·d)) could promote intestinal villi growth, crypt deepening, and alleviate the effect of enterotoxin Escherichia coli (E44813) on intestinal stress. In vitro studies have found that theanine can inhibit the proliferation of mouse liver cancer cells by improving immune capacity.

Theanine also
has significant anti-stress and regulatory metabolic effects in animals and humans.

After 2 weeks of gavage intervention, L-theanine (50 mg/kg) can inhibit glucose and nitrogen absorption and insulin secretion, improve glucose tolerance and insulin sensitivity, and reduce ethanamine levels and the risk of type II. diabetes mellitus by downregulating the expression of relevant genes in the small intestine of rats.

In addition, theanine can also enhance the protective effect against doxorubicin (DOX)-induced nephrotoxicity in rats by enhancing the antioxidant system of glutathione (GSH) and its related enzymes.