- Promotes Relaxation Without Drowsiness*
- Supports Nervous System Health and Function*
- May Support Blood Pressure Already Within the Normal Range*
- Supports Antioxidant and Detoxification Mechanisms
- May Support Liver Health and Function*
Green tea, prepared from the Camellia sinensis plant, has been consumed since ancient times for its calming influence. Modern research has looked into this â€œancient wisdomâ€ and revealed that L-theanine, an amino acid found almost exclusively in green tea, has specific and positive effects on the brain and nervous system, especially the promotion of relaxation without drowsiness.*
Neurological and Brain Support Human studies suggest that within 40 minutes of oral administration, L-theanine positively affected alpha waves in the brain, a phenomenon indicating relaxation. An eight-week, randomized, double-blind, placebo-controlled study, based on the premise that L-theanine â€œpossesses neuroprotective, mood-enhancing, and relaxation properties,â€ suggested that 400 mg of L-theanine
per day was found to be safe and effective. A double-blind counterbalanced study suggested that oral L-theanine positively influenced heart rate and salivary IgA levels, attenuated sympathetic nervous system activation, and positively supported individualsâ€™ normal response to stress. In examining L-theanineâ€™s effect on cognition, a randomized, double-blind, placebo-controlled study of 91 subjects suggested that individuals taking a combination of L-theanine and green tea extract experienced significant increases in theta waves in several areas of the brain, indicative of increased cognitive alertness.*
In cell studies, L-theanine appears to support neuronal health despite the presence of environmental toxins that ordinarily would increase the vulnerability of nigral dopaminergic neurons and negatively affect their function. L-theanine also appears to support neurological health by exerting a positive and significant impact on neurotrophic factors in the brain and assisting cell-signaling activity.*
Research into animal neurochemistry suggests that L-theanine positively supports overall nervous system health and activity due to its
positive effects on serotonin, dopamine, and GABA levels, as well as its modulation of excitatory and inhibitory neurotransmission.
L-theanine crosses the blood-brain barrier intact and may continue to balance neurochemistry by blocking glutamate transport, significantly reducing levels of extracellular glutamate and supporting the release of dopamine and glycine from neurons.*
Hepatic, Detoxification, and Cardiovascular Support Research studying ethanol metabolism and hepatic toxicity in animals suggests that administration of L-theanine increases liver alcohol dehydrogenase and aldehyde dehydrogenase activity, reducing blood ethanol concentration within one hour compared to controls. It is also suggested that L-theanineâ€™s effect on cytochrome P450 2E1 activity,
glutathione recovery, and antioxidant mechanisms supports healthy liver tissue and function. L-theanine was observed to significantly inhibit hydrogen peroxide-induced cell death, and it may play an important role in the maintenance of liver health. L-theanine, along with green tea polyphenols, was found to provide antioxidant activity that supports healthy LDL and oxidation levels and may subsequently
support cardiovascular health. Animal and human studies suggest that L-theanine supports healthy blood pressure in the normal range, in part because it moderates the negative side effects of caffeine.*
L-theanine and SuntheanineÂ®
Although theanine exists in both L- and D- forms, L-theanine is the preferred form due to its greater
intestinal absorption and renal retention. An analysis of six commercial products revealed that five of them contained the poorly absorbed D-theanine along with L-theanine. Only Suntheanine, the brand in CinDen Nutritionalsâ€™ Sere-Calm, appeared to contain only the preferred L-theanine enantiomer. Suntheanine is protected by several patents that cover applications, such as reducing anxiety and promoting relaxation. The FDA has consequently approved the following structure/function claims regarding L-theanine: it reduces stress, it eases nervousness due to common everyday overwork and fatigue, and it reduces nervous irritability. CinDen Nutritionalsâ€™s Sere-Calm provides 400 mg of Suntheanine L-theanine per two-capsule dose.*
- Juneja LR, Chu D-C, Okubo T, et al. L-theanine â€“ a unique amino acid of green tea and its relaxation effect in humans. Trends Food Sci Technol. 1999;10:199204. http://dx.doi.org/10.1016/S0924-2244(99)00044-8.
- Ritsner MS, Miodownik C, Ratner Y, et al. L-theanine relieves positive, activation, and anxiety symptoms in patients with schizophrenia and schizoaffective disorder: an 8-week, randomized, double-blind, placebo-controlled, 2-center study. J Clin Psychiatry. 2011 Jan;72(1):34-42. [PMID: 21208586]
- Kimura K, Ozeki M, Juneja LR, Ohira H. L-Theanine reduces psychological and physiological stress responses. Biol Psychol. 2007 Jan;74(1):39-45. [PMID: 16930802]
- Park SK, Jung IC, Lee WK, et al. A combination of green tea extract and l-theanine improves memory and attention in subjects with mild cognitive impairment: a double-blind placebo-controlled study. J Med Food. 2011 Apr;14(4):334-43. [PMID: 21303262]
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