L-Theanine primes immune cells that fight infection

L-Theanine is a non-protein forming amino acid that is extracted from the tea plant. L-Theanine is used in the daytime for improving stress and nervousness and at night with higher doses to improve the quality of sleep. Catechins are the antioxidants in the Green Tea plant.

In this review researchers at the Division of Rheumatology, Allergy & Immunology, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School note that supplementing individuals with capsules containing L-Theanine and catechins (green tea antioxidants) has recently been shown to decrease the incidence of cold and flu symptoms, while enhancing gammadeltaT cell function. Human gammadeltaT cells are lymphocytes, a type of white blood cell. These cells are a subset of T cells and are a first line of defense against microbes and tumors. These gammadeltaT cells can be primed by certain short-chain alkylamines. The largest dietary source of alkylamines is L-Theanine.

These primed gammadeltaT cells have an enhanced capacity to proliferate and to secrete cytokines (immune system messengers) upon exposure to a wide variety of microbes and tumor cells. The article is published in the February 2008 issue of the journal Nutrition Review.